# Has Anyone Fooled the MES Temp Sensor Before?



## tallbm (Dec 30, 2016)

Hi everyone, I'm new here and just posted in Roll Call about 5 minutes ago.

*Has anyone found a way to fool/trick the MES temp sensor so that it reads about 30 degrees cooler than normal?*

Why am I asking this?  Well read on below for many long and boring details :)

My MES40 reports 275 degrees while my Maverick reports 245 degrees where my meat is and the MES then cycles off the heating because it believes it has reached 275 degrees.  There is a 25-30 degree difference all the time.  

This means I can never get over 245 degrees to hit 275 degrees for many good cooking reasons (hotter smokes, crisping skin, meat bark, etc, etc.).

I have searched a ton on this site over this issue (via the search feature, and via targeted Google searches isolated to "site:smokingmeatforums.com") and found many people talking about this common MES problem and many people troubleshooting to get to the root cause.

What I haven't found is anyone saying something like

"To fool the MES sensor so it reads 20 degrees low, just wrap the sensor in a ball of foil and that will do."

I'm looking for a quick simple "work around" fix so I can have the MES read 30 degrees low thereby allowing a REAL 275 degrees read by my Maverick instead of hitting the current upper limit of 245 degrees.  

I intend to let my Maverick alarm notify me of the actual temperature at 275 degrees and adjust the MES temperature to hold as appropriate.

For more Info on my setup see the following work I have put in so far:

-Applied 12"x12" ceramic tile heat sink fix to even out temps inside smoker (did this after testing 4 probes in various areas and having different results, after tile fix applied 

-Applied mailbox cold smoking mod

-Using an AMNPS (not tube but tray)

-Using Maverick ET-733


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## SmokinAl (Dec 31, 2016)

As you have read this is a common problem with the MES.

Some guys luck out & the MES controller will say 275, but the temp is really 300.

In your case it's the opposite & the only thing you can do is contact MB customer service & they will probably send you a new controller.

Hopefully you will get one that is more accurate or at least is inaccurate in the right direction.

Good luck!

Al


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## tallbm (Jan 2, 2017)

SmokinAl said:


> As you have read this is a common problem with the MES.
> 
> Some guys luck out & the MES controller will say 275, but the temp is really 300.
> 
> ...


Thanks for the info.  I'll play with covering the sensor a bit while I contact Masterbuilt and see what they say about a replacement control unit :)


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## daveomak (Jan 3, 2017)

Put a therm in the exhaust hole and check the temp...   The MES smokers have terrible homogenized heat...  there are hot zones, cold zones etc...


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## tallbm (Jan 3, 2017)

DaveOmak said:


> Put a therm in the exhaust hole and check the temp...   The MES smokers have terrible homogenized heat...  there are hot zones, cold zones etc...


Good idea.

During the break in I tested 4 areas across the smoker and had big temperature variances as most report.

I then applied the 12"x12" ceramic tile heat sink work around and that evened things out quite a bit. 

I'll put a probe in the exhaust hole and see what it is reporting now.

I'm also going to take a small piece of mesquite or oak or some type of seasoned smoking wood and drill a hole the size of the sensor and put it over the sensor and see if I can figure out how to trick it a little bit while using my Maverick to help me manage the real temp.

I don't plan to go crazy but I figure covering partial way, and/or using a few different pieces/sizes of wood may be some interesting experiments to see what happens.  Again, I plan on doing this safely while using the maverick and other probes to see whats going on in the box.

Thanks :)


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## Bearcarver (Jan 3, 2017)

If you're only getting 245° with an Accurate Maverick when it's set for 275°, like Al said, call Masterbuilt, because you paid for a Smoker that goes from 100° to 275°.

To check for sure, before you call them, Boil test your maverick smoker probe, and then put it very close to the Heat sensor on the back wall (looks like a little toggle switch). That should show how close the MES is to your Maverick.

If it's not as bad as you thought, just put the Maverick probe near your food, and adjust your MES until the Maverick reads the temp you want.

I don't know why anybody would care what the temp is in your top vent, unless that's where you put the meat.

Once you test & find your Maverick to be accurate, ALWAYS trust your Maverick---Not the MES readout.

Bear


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## tallbm (Jan 3, 2017)

Bearcarver said:


> If you're only getting 245° with an Accurate Maverick when it's set for 275°, like Al said, call Masterbuilt, because you paid for a Smoker that goes from 100° to 275°.
> 
> To check for sure, before you call them, Boil test your maverick smoker probe, and then put it very close to the Heat sensor on the back wall (looks like a little toggle switch). That should show how close the MES is to your Maverick.
> 
> ...


Thanks for the advise.  I'll be sure to do the boil test before calling them.   I hope they send me a control that is more accurate or has the opposite problem where it reads lower than reality.  That would be nice for crisping chicken skin :)


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## pa42phigh (Jan 3, 2017)

My smoker is 3 years old I had this problem to my smoker was running cooler that it was saying and it would stop calling for heat I unhooked the snapdisk or high temp control  while not safe apparently this was cause of the problem working fine now


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## floridasteve (Jan 3, 2017)

Bearcarver said:


> If you're only getting 245° with an Accurate Maverick when it's set for 275°, like Al said, call Masterbuilt, because you paid for a Smoker that goes from 100° to 275°.
> 
> To check for sure, before you call them, Boil test your maverick smoker probe, and then put it very close to the Heat sensor on the back wall (looks like a little toggle switch). That should show how close the MES is to your Maverick.
> 
> ...


I did that, and they sent me a new controller, but it didn't fix the problem.  What I'm finding is that if I set the temp at 275 and put probes in various locations in the smoker, they all read close to 275 UNTIL i put something on one of the racks.  Then, the probes on that rack and above read 30* low, while those below the rack read 275.

I tried putting a large piece of 1" thick granite on the bottom shelf to act as a defuser to send the heat up the sides, and to also act as a heat sink, but that did nothing.  It's got to be heat distribution management.  I've got a couple cheap USB fans -- I think the next time I'm doing a long cook I'll try blowing some air in the chip shoot, or sucking the exhaust out faster, or just circulating air around inside the chamber.

For now when I cook birds, I use my mini. LOL

Oh, I have a 1 yr old gen 2.5 and just replaced the heating unit.  I always run it with the chip tube a couple inches out and the exhaust wide open. I have a dual probe Maveric and a 4 probe i'grill, all checked in boiling water.


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## tallbm (Jan 3, 2017)

I'm not sure I"m going to start unhooking the sensor just yet.  I did have the idea of wiring it into a probe but I don't know enough about the existing system to know if the controller would read a probe the same way it does it's current sensor.  If that were the case I could buy a 6ft replacement probe, wire it up and then I could have a probe that measures heat wherever I put it.  So if It's at the top rack, bottom rack, upper left corner, etc. etc. The unit would reflect the temp where I needed it to be measured.

Sounds like a great idea in theory but again that is a lot of speculation, research, and one potentially damaged unit leaving me without a smoker and a hole in my wallet :)

I do the mailbox mod so no fans blowing into the unit for me but if you do it please report back with your findings.

It dawned on me about 10 minutes ago that instead of using a piece of wood over the sensor I could use a wine cork.

I could much more easily modify a wine cork than a piece of wood and all I need to do is drink more wine to get more corks to carve/cut up and work with :D

I won't get to do any of this until the weekend though and not until after I make my first attempt at Ground Formed Bacon which I plan to do this weekend.

Man this is all exciting stuff.  So many firsts for me and so many little projects :D


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## Bearcarver (Jan 3, 2017)

FloridaSteve said:


> I did that, and they sent me a new controller, but it didn't fix the problem.  What I'm finding is that if I set the temp at 275 and put probes in various locations in the smoker, they all read close to 275 UNTIL i put something on one of the racks.  Then, the probes on that rack and above read 30* low, while those below the rack read 275. *If you put something big on a shelf, it will hold the heat below the "something", and the heat will build up in the lower section & shut the heating element off, leaving the upper part at a lower temp.*
> 
> I tried putting a large piece of 1" thick granite on the bottom shelf to act as a defuser to send the heat up the sides, and to also act as a heat sink, but that did nothing.  It's got to be heat distribution management.  I've got a couple cheap USB fans -- I think the next time I'm doing a long cook I'll try blowing some air in the chip shoot, or sucking the exhaust out faster, or just circulating air around inside the chamber.* Here again, if that piece of granite is big enough it will trap the heat below it. Just a possibility, because I don't know how big your granite hunk is.*
> 
> ...


*Don't know if that's any help.*

*Bear*


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## dr k (Jan 3, 2017)

TallBM said:


> I'm not sure I"m going to start unhooking the sensor just yet.  I did have the idea of wiring it into a probe but I don't know enough about the existing system to know if the controller would read a probe the same way it does it's current sensor.  If that were the case I could buy a 6ft replacement probe, wire it up and then I could have a probe that measures heat wherever I put it.  So if It's at the top rack, bottom rack, upper left corner, etc. etc. The unit would reflect the temp where I needed it to be measured.
> 
> Sounds like a great idea in theory but again that is a lot of speculation, research, and one potentially damaged unit leaving me without a smoker and a hole in my wallet :)
> 
> ...


I have a Mes 40" gen 1 and I use a deflector between the sensor and the heating element so the heat doesn't go up the back wall past the sensor out the top vent.  I raise my empty water pan and it is an obstacle to even out heat on the second to the top rack.  The water pan can be placed at any level.  It's a vertical smoker with 4 to six racks and whatever rack the Mes sensor is closest to should be the closest to the Mes controller temp.  But most likely not and then you have the other racks the sensor is no where near.  But people go by calibrated air probe placed next to the food.  I use the deflector in the pic below and elevate the water pan for even heating on the top two racks. 













CAM00897.jpg



__ dr k
__ Aug 28, 2016






Fold in half and put in the corner above the heating element













CAM00898.jpg



__ dr k
__ Aug 28, 2016






I'm happy with my results but may raise the water pan to the second from the top level and experiment. 

-Kurt


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## tallbm (Jan 3, 2017)

Dr K said:


> I have a Mes 40" gen 1 and I use a deflector between the sensor and the heating element so the heat doesn't go up the back wall past the sensor out the top vent.  I raise my empty water pan and it is an obstacle to even out heat on the second to the top rack.  The water pan can be placed at any level.  It's a vertical smoker with 4 to six racks and whatever rack the Mes sensor is closest to should be the closest to the Mes controller temp.  But most likely not and then you have the other racks the sensor is no where near.  But people go by calibrated air probe placed next to the food.  I use the deflector in the pic below and elevate the water pan for even heating on the top two racks.
> 
> Fold in half and put in the corner above the heating element
> 
> ...


Thanks for the info Kurt.  I am using the 12"x12" ceramic tile mod which I believe is similar to your deflector.  I have the tile on top of the chip feeder box putting the tile between the heating element and the MES temp sensor/thermistor.  I did not have the the water tray in, I've removed that according to what I read with some of the deflector and tile mod posts.

I did quite a bit of research today and found some amazing work done by guys that have posted on this forum.  

Basically I am convinced that the sensor/probe/thermistor that Masterbuilt uses for the controller is simply cheap and and has a high margin of error.

The user Sigmo did some good testing here  http://www.smokingmeatforums.com/t/...eading-on-display-higher-than-actual-temps/20

While the user ForageFish went a step beyond basically performing the same test as well as checking the voltage here http://www.smokingmeatforums.com/t/139353/mes-controller-reverse-engineering

Additionally ForageFish put together a solution that seems to confirm that Masterbuilt just uses a poor thermistor for the contoller temperature.

ForageFish actually increased the resistance of the thermistor circuit in a clever way to basically correct the flaw.

I'm no electrical engineer, electrician, or a hardware circuitry designer so any of you guys that happen to be one please feel free to correct anything I may misstate, but I believe I can translate what I have found into the following.  

*Info from Posts Explained:*

The thermistor (sensor/probe) that the MES controller uses is so poor that it does not behave to the specification it is calibrated to thereby reporting a higher temperature than reality.

Best analogy I can give that you buy a 12 inch ruler and you use it to measure stuff and then find out that the last 2 inches of the ruler are not calibrated properly and lead to a ruler that is 11.5 inches in length though it is reporting/claiming 12 inches in length.  Doh!!! 

Since the MES thermistor seems to be an NTC type resistor (it appears so according to ForageFish's research and solution) the resistance lessens as the temperature around the thermistor goes up but get's faulty after certain temperatures because the resistance of the thermistor/resistor is not working as defined in the specification.

ForageFish's solution was to test temps all probe temps, capture Ohms of the thermister circuit, use the data to do the math and figure out how much resistance needed to be added to the MES thermistor circuit to get the near correct reading sent to the MES controller.  With the MES thermistor resistance about corrected the MES controller temp would be very close to the real temp reported by his Omega probe.  

His solution wasn't full proof as the faulty thermistor with added resistance would report about 10 degrees higher at ambient temps but I don't think that is an issues.  It is simple to dial up the temp 10 degrees than reported higher at such low temps. 

ForageFish increased resistance to the MES thermistor circuit by adding what appears to be an SMD chip resistor in parallel to the existing resistor on the MES controller board.  Well it looks like an SMD chip resistor but don't quote me on it and feel free to confirm the exact type of resister added on your own :)  

So in short the solution was to get closer to the defined/proper specification (resistance) of the MES thermistor so it would report properly.

In my mind I think replacing the MES thermistor/probe/sensor with a new NTC thermistor/probe/sensor that is more accurate or in a better resistance range would solve the issue as well.

So basically replace the bad thermastat with a good/better one that is compatible.
 

*In Conclusion:*

I still plan to reach out to Masterbuilt but seeing all this information I don't think they are going to be able to do do much other than send a new unit unless they want me to replace the thermistor/probe/sensor myself with one they send me.

I still plan on messing around with the cork idea.  Hopefully I can insulate the MES thermistor/sensor/probe so much that I can hit higher temps in my MES.  I will simply and regulate the temp manually on the controller according to what my Maverick reports.

Let me know if all this info makes some kind of sense lol.

Again, please feel free to correct anything I may have misstated and I will correct the info.  I don't want to be putting bad or misleading info to be out there in the world for other people to stumble over :)


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## tallbm (Jan 5, 2017)

Update:  Yesterday I called Masterbuilt support and the guy asked a few questions about my issue.  I gave him my model number and told him when/where (Nov 2016/Academy Sports)  I purchased the MES and after looking he said "it is a controller issue".

I understand that customer service reps are not techs and such so I was skeptical about his answer so I flat out asked him..

"So is this a known issue with the models sold around the time I purchased mine?"

His answer was "yes".  He said for me to reply back to his email with my serial number (won't have that until this weekend) and the model number and they will send me out a new controller free of charge.

I am still skeptical that a new controller will fix the issue but only time will tell.

In any case with two controllers I can play around with ForageFish's chip resistor mod and see if that "fixes" the old controller.  If so I will have two working controllers in case one craps out after the warranty!

I'll keep you guys posted :)


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## tx0303 (Jan 5, 2017)

I recently got a Gen1 MES40 and was having the same problem as the OP. I could tell the temperature was not right so I purchased a Maverick and sure enough, with the control set on 275, the best I could do on the second shelf was 245. Did some pondering and experimenting and came to the same conclusion as Dr K. The drip pan on the fourth shelf forces the heat flow to the back wall, then up to the sensor giving a higher reading than the middle of the cabinet. I moved the drip pan up to the third shelf and success, the control now reads within 5 degrees of the Maverick probe on the second shelf. That I can work with. I think giving the rising heat a larger initial air mass before deflection causes more turbulence within the cabinet and evens out the temperature rather than the heat racing toward the vent along the walls.


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## Bearcarver (Jan 5, 2017)

TX0303 said:


> I recently got a Gen1 MES40 and was having the same problem as the OP. I could tell the temperature was not right so I purchased a Maverick and sure enough, with the control set on 275, the best I could do on the second shelf was 245. Did some pondering and experimenting and came to the same conclusion as Dr K. The drip pan on the fourth shelf forces the heat flow to the back wall, then up to the sensor giving a higher reading than the middle of the cabinet. I moved the drip pan up to the third shelf and success, the control now reads within 5 degrees of the Maverick probe on the second shelf. That I can work with. I think giving the rising heat a larger initial air mass before deflection causes more turbulence within the cabinet and evens out the temperature rather than the heat racing toward the vent along the walls.


Generally speaking the biggest problem with the Gen #1 was the fact that the heating element is on the right side, and so is the top vent.

So the heat would come from the right half of the smoker & run straight up the right side & out the top vent on the right.

That would make the right side hotter than the left.  I solved this years ago, by putting a piece of metal (Heat deflector) on the right side, just above the water pan in it's normal position. This would push the heat from the right to as far to the left as I wanted, by a simple adjustment to that heat deflector. I did this for 4 years, until I got my New Gen #2.5 MES.

The water pan had little to do with this---It was the fact that both the heating element & the top vent were on the right.

I told Masterbuilt about this problem years ago & they moved their top vent to the left side---Problem Solved !!!

Bear


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## dr k (Jan 5, 2017)

TX0303 said:


> I recently got a Gen1 MES40 and was having the same problem as the OP. I could tell the temperature was not right so I purchased a Maverick and sure enough, with the control set on 275, the best I could do on the second shelf was 245. Did some pondering and experimenting and came to the same conclusion as Dr K. The drip pan on the fourth shelf forces the heat flow to the back wall, then up to the sensor giving a higher reading than the middle of the cabinet. I moved the drip pan up to the third shelf and success, the control now reads within 5 degrees of the Maverick probe on the second shelf. That I can work with. I think giving the rising heat a larger initial air mass before deflection causes more turbulence within the cabinet and evens out the temperature rather than the heat racing toward the vent along the walls.


Your the first person that moved the pan up since I've been posting about even heat on the top two racks. Since I use the mailbox mod I removed all the chip tray metal above and below the heating element.  My heating cycles shortened since I no longer have a heat sink. Now outside air flows in over the exposed element, mixes then rises then has to go around the elevated water pan. If your cooking on the top two racks,  then you have to create chaos as the air rises so predictable currents rivers of air aren't so prevalent. If you have a full smoker the food has you covered. 
-Kurt


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## sigmo (Jan 9, 2017)

TallBM said:


> I'm not sure I"m going to start unhooking the sensor just yet.  I did have the idea of wiring it into a probe but I don't know enough about the existing system to know if the controller would read a probe the same way it does it's current sensor.  If that were the case I could buy a 6ft replacement probe, wire it up and then I could have a probe that measures heat wherever I put it.  So if It's at the top rack, bottom rack, upper left corner, etc. etc. The unit would reflect the temp where I needed it to be measured.
> 
> Sounds like a great idea in theory but again that is a lot of speculation, research, and one potentially damaged unit leaving me without a smoker and a hole in my wallet :)
> 
> ...


The problem with insulating the temperature sensor is that, ultimately, it will not achieve what you want (a different calibration of the sensor).  All it will do is alter the speed of response of the sensor.  It'll just slow the response down.  And you don't really want that.  Slowing the sensor down will result in larger temperature swings because the heater will stay on for longer periods and stay off for longer periods.  You really do want the sensor to respond rather quickly to get a "smoother" more even temperature (over time) in the smoker.


Dr K said:


> I have a Mes 40" gen 1 and I use a deflector between the sensor and the heating element so the heat doesn't go up the back wall past the sensor out the top vent.  I raise my empty water pan and it is an obstacle to even out heat on the second to the top rack.  The water pan can be placed at any level.  It's a vertical smoker with 4 to six racks and whatever rack the Mes sensor is closest to should be the closest to the Mes controller temp.  But most likely not and then you have the other racks the sensor is no where near.  But people go by calibrated air probe placed next to the food.  I use the deflector in the pic below and elevate the water pan for even heating on the top two racks.
> 
> 
> 
> ...


That's more like it.

As many of the posts have pointed out, even if the sensor is accurate, you'll get hot and cold spots in the smoker if the heat isn't evenly distributed.

Having the sensor positioned directly over the heating element has good and bad aspects.

The good is that it speeds the response of the system, resulting in more rapid cycling of the heating element, giving a more even temperature in the unit.  It's also something of a safety thing, too, because it assures that no part of the smoker is likely to be too hot.   When we block the sensor's ability to "see" the heat, we get higher temperatures and perhaps larger swings in temperature.

The bad is that the sensor "sees" the heat coming right off of the heating element, so it overestimates the temperature in the rest of the smoker.  And this is the goal of people installing baffles and such to prevent the sensor from being in the direct path of the heated air rising up from the heating element.  Again, there are pros and cons to anything we do, so it's just good to think about it and be careful to get what you really want.

Quote:


Bearcarver said:


> Generally speaking the biggest problem with the Gen #1 was the fact that the heating element is on the right side, and so is the top vent.
> 
> So the heat would come from the right half of the smoker & run straight up the right side & out the top vent on the right.
> 
> ...


Yeah.  This gets to the problem, too!

Ideally, we'd have much better mixing of the air inside the smoker so the smoke and temperature would stay very even throughout the whole volume.

But these are inexpensive devices, and there's only so much they can do.  And as folks have pointed out, the way you load the food into them, any baffles we put in, etc., all change the dynamics.  Every time you smoke something, the way you load the food in changes it all.

I've read a bit about commercial smokers, and the various manufacturers often talk a LOT about their systems for directing the heat and smoke to try to get very even cooking and smoking.  Often, things are fan-forced, and even have moving baffles that shift the direction of airflow constantly to get even cooking and smoking over the entire volume of the smoker so that the products are cooked and smoked evenly.

But those smokers cost a LOT, I'm sure.

Without active stirring of the air in the smoker, you just have to try your best to baffle things and load the food to get the heat and smoke to be as even as possible.  I tend to use disposable foil steam-pan covers and the like as baffles that I can put in place and move around depending on the sizes and shapes of the foods I'm smoking to always try to even things out.

I just got a used fan for a convection oven that I will likely try to "kludge" into my MES 40 at some point.  I will likely set up a controller to cycle it on and off so it's not blasting the air around inside of the smoker too badly, yet keeps things stirred a little better.  That's going to take some experimenting.  Keep in mind that this fan will only stir the air within the smoker.  It's not going to force air into or out of the smoker.  I'll either stay with convection for that, or add some different kind of fan setup if I decide that needs to be forced.

First things first, I guess!

Fancy laboratory drying ovens and incubators, and fancy commercial smokers seem to all employ some kind of active stirring of the air.  And if I was going to build my own smoker, I would use a design based on a lot of those ovens I've seen that use the side walls as air plenums, with perforations that force the air to flow horizontally across the chamber from one side over to the other (one side sucking, the other blowing, with the heater in the air path, but hidden).  But for now, I just want to see if I can make my existing little MES work a bit better.

Once I figure out what I'm going to do, and actually make some progress and have something to report, I'll make a thread about it.

Part of the modifications will ultimately be to use a different system entirely to control the heater based on more accurate temperature sensors.

But again, the first step I want to try is just actively stirring the air in the smoker to try to get more even heat and smoke.

This is an interesting thread, and touches on a lot of things we all seem to run up against with these smokers.


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## tallbm (Jan 9, 2017)

That is great input Sigmo!

I just received confirmation from Masterbuilt that my new controller unit is on the way so I will have that to toy with myself.  I also bought a flexible ducting hose to try and "duct" the exhaust from the opposite side of where the vent/damper is currently located.  This would have the air flow across the smoker rather than straight up from element to vent/damper.

Lots of experiments on the list lol.


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## floridasteve (Jan 9, 2017)

Bearcarver said:


> *Don't know if that's any help.*
> 
> *Bear*



Thanks Bear.  You confirmed what I suspected.  Now to figure out a way to get the heat to distribute.  I fan inside the unit stirring the air up would probably be best, but I couldn't imagine it lasting very long. LOL


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## miatawnt2b (Jan 9, 2017)

I've fooled the stock sensor... but in the opposite way you need.  Same info applies though.  You just need the proper resistor in parallel. ohms law.

http://www.smokingmeatforums.com/t/238214/350-in-a-mes30-yep-heres-my-mod

-J


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## Bearcarver (Jan 9, 2017)

miatawnt2b said:


> I've fooled the stock sensor... but in the opposite way you need.  Same info applies though.  You just need the proper resistor in parallel. ohms law.
> 
> http://www.smokingmeatforums.com/t/238214/350-in-a-mes30-yep-heres-my-mod
> 
> -J


Next time you take it to 350°, put your ear near the side wall (Top left is cool), and listen.

I had an MES accidentally get to 350°, and I could hear what sounded like the insulation between the walls crackling.

I would not intentionally take one over 325° MAX. JMO

Bear


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## sigmo (Jan 11, 2017)

TallBM said:


> That is great input Sigmo!
> 
> I just received confirmation from Masterbuilt that my new controller unit is on the way so I will have that to toy with myself.  I also bought a flexible ducting hose to try and "duct" the exhaust from the opposite side of where the vent/damper is currently located.  This would have the air flow across the smoker rather than straight up from element to vent/damper.
> 
> Lots of experiments on the list lol.


I think the experimenting is half of the fun for me!  I suspect the same is true for a lot of us.

The duct to collect the exhaust air over at the opposite corner from where the factory vent is located would be good for me, too.  The vent is directly above the heater in mine, too.

I've put some of those cheesy disposable aluminum-pan bits in various places to help direct the airflow.  If I'm not using the top rack, I usually put a sheet of that thin aluminum on the top rack such that it blocks off all but the leftmost four inches or so.  Thus, the air has to go over to the left before it can get to the vent.  But of course, that monopolizes that top rack.

I don't remember who it is on here, but they posted a photo showing how they mounted a piece to do that same thing, but they mounted it to the "ceiling" of the smoker, creating that same sort of plenum, but without wasting so much of the smoker's space.  I may have to do that or use your hose idea.


FloridaSteve said:


> Thanks Bear. You confirmed what I suspected. Now to figure out a way to get the heat to distribute. I fan inside the unit stirring the air up would probably be best, but I couldn't imagine it lasting very long. LOL


My wife bakes fancy cakes for weddings and the like.  And years ago, I installed a small stirring fan in our home oven to even the temperatures out in that unit.  But here's the secret:

I used a fan that I took out of an old gas chromatograph's column oven.  The way they work is simply to have a very long shaft between the motor and the little squirrel cage.  The motor mounts outside of the oven, and that long shaft pokes through a hole that goes all the way from the outside of the oven, through the insulation, and into the interior.  So the motor and bearings do not experience the heat of the oven.

And the little convection oven fan I got works the same way.  It has a very long shaft, and it even has a second small set of fan blades back near the motor.  I've seen these referred to as a "heat slinger" in the description of some "draft inducers" which have the same kind of task.  The idea is to act as a heat sink to cool the shaft before it goes into the front bearing.

One downside of this design is that you need to come up with some sort of enclosure to surround the motor which, of course, is mounted to the outside of the smoker.

The idea of putting a fan entirely inside of the smoker is not good if you're using high temperatures because most would not be designed to handle such temperatures and might give off some nasty fumes when they are heated, not to mention the fact that they'd likely not last very long.

I admit, though, that I have used a little computer fan to stir the smoke up when cold smoking, but even at that, I suspect the smoke might eventually gum up the bearings.  But since the little fans are so cheap, I was willing to risk it for cold smoking.


miatawnt2b said:


> I've fooled the stock sensor... but in the opposite way you need.  Same info applies though.  You just need the proper resistor in parallel. ohms law.
> 
> http://www.smokingmeatforums.com/t/238214/350-in-a-mes30-yep-heres-my-mod
> 
> -J


Pardon this long story, but:

I was looking for a way to find very cheap meat probes to use with a fancy industrial controller, and after looking around, found that I could buy entire temperature meters with meat probes on EBAY, from China, for about $8 each.  So even if I throw the meter away, I've got a meat probe for $8.

Being too impatient to wait for the cheap meter/probe units to arrive, I took the probe from one of my existing electronic oven thermometers, and characterized the probe at a variety of temperatures.  It turns out that they used a thermistor type probe, and that's no surprise since they're inexpensive.

The problem is that these thermistors are very non-linear.  So you need to implement a conversion to linearize the thermistor.  The one I tested was a negative temperature coefficient, and probably what they'd call a 400K Ohm thermistor.  The fancy PLC I plan to use has special input modules for resistances, and the "brains" actually implement some standard thermistor linearizations that you can tweak. But these input modules are not cheap, and the only ones I could find used, were for 40K thermistors.  I'm still waiting to get a few of the $8 units, but I fear they'll be the same.

I also found a few articles about how to implement the math to linearize such probes or how to approximate a linearization with a very simple two-resistor circuit.  Just do a web search for "thermistor linearization", and you'll get a lot of interesting hits.

I wonder if Masterbuilt uses the two-resistor approximate linearization circuit.  And if so, I wonder if we couldn't actually do a pretty good job of tweaking one in, over a rather wide range, by changing the values of those two resistors (assuming that's what they use, and further assuming they're accessible on the PCB of their controller).

I could also very well imagine them directly reading the resistance, and then implementing the linearization in the firmware of the microcontroller.  If that's the case, the best you can probably do is exactly what you folks are doing.  Either put a resistor in series or one in parallel depending on which direction you want to "push" the readings.  But the problem, as you folks have already noted, is that you can only achieve perfect adjustment at one temperature.

But then again, that might well be good enough!

As Bear mentioned, you probably don't want to set things up to heat these units up beyond their original design limits.  And as I've talked about before, you want to make sure that you're really comparing temperatures right at the smoker's sensor before adjusting things.  The temperatures can vary so widely from one place to another in the smoker that you must take that into account before assuming that the smoker's sensor/controller is really off.

I would hope that the snap-disk would prevent things from overheating too badly in any case.  And if I found that the snap disk was tripping prematurely, I'd likely replace it rather than jumper around it, defeating that safety system.  As Bear pointed out, I don't know what sort of insulation they use, but if it's the foam stuff, it probably can't handle temperatures too far above what the factory controller is supposed to give us.

If I was making my own smoker from scratch, I'd use some mineral insulation of some sort so that I could run it up to "oven" temperatures if I wanted to.  But I'm not sure what these MESs use.


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## Bearcarver (Jan 11, 2017)

*Heat Deflector for Gen #1 MES Units:*

This is an old picture of my Heat deflector in my old MES 30 Gen #1.

The Aluminum plate resting just above the Water Pan is actually sitting on a metal prop on the left end.

I can raise that left side to Direct more heat from the right side to the left & middle, or I can lower the left side to get less heat directed over to the left. The left & right heat balance can be had easily with this. (I don't need this in my Gen #2.5 MES 40

This Works Awesome!!!

Note:  Putting something on the ceiling (Like a Plenum) to direct the heat where you want it will allow the heat to rise on the right side all the way up through the smoker, and then jump over when it gets to the top.

Deflecting the heat at the bottom, like my Deflector does, causes the heat to go where I want it, before it rises through the food on the racks.

Bear













DSC02348.JPG



__ Bearcarver
__ Jun 24, 2011


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## tallbm (Jan 12, 2017)

Well I attempted to make a little duct out of some materials I had.  This is version 1 and it is a bit rough but I think it will be a good first attempt and if it works I'll stick with it.

Added a 2 inch elbow bracket using the screw that was already in the smoker.  It holds the chord to the meat probe to the back top of the smoker.  I just unscrewed the screw and then added back with the elbow bracket.













DSC_8849.JPG



__ tallbm
__ Jan 12, 2017






Used a foil pan and some 3inch foil semi flexible expandable ducting and some high temp Flue tape to make this contraption.

I cut as slit about 3 inches from one end of the duct and then forced an overlap to snugly fit into the exhaust vent hole in the MES.  Once it fit I Flue taped it.  The normal 3 inch diameter is slightly oversized for the MES exhaust hole so the duct must be tapered down a little bit.  The image below does not show the tapering, just the 3 inch duct.













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__ tallbm
__ Jan 12, 2017


















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__ tallbm
__ Jan 12, 2017


















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__ tallbm
__ Jan 12, 2017






Here is what it looked like installed.  The round duct at the left end was just me re-purposing materials from the 3 inch duct where I had been playing around with the design. The bracket basically holds everything up as the coil fits very snugly into the MES vent hole.













DSC_8852.JPG



__ tallbm
__ Jan 12, 2017


















DSC_8853.JPG



__ tallbm
__ Jan 12, 2017


















DSC_8854.JPG



__ tallbm
__ Jan 12, 2017






To do over I would start by installing the elbow bracket in place and then measure the amount of space I had available on the bracket for the homemade duct to sit.  The bracket idea didnt come to me until I built the contraption and couldn't get it to stick in place using wire.  

Putting the bracket in place first and then doing measurements would allow for a homemade duct to be created that would be more of a flush/perfect fit.  

I would then do a better measurement job on the 3" duct that goes into the MES exhaust vent slot.  As you can see mine is a little too long and my homemade duct was fastened too low.

After everything was measured and fit properly I would flue tape the crap out of the contraption and install it.

Doing over again this approach would create a device that takes up the least amount of space in the the smoker and keeps everything fitting as flush as possible.

Oh, I did use plain foil around the 3 inch duct pipe that goes into the MES exhuast hole.  The foil was mashed to the device while in place to fill any gaps in fitting the 3inch duct to the MES exhaust hole.

I plan to attempt a standing rib roast or pork ribs Sunday morning so I will know how it handles with smoke.

I can probably do a temp check with probes before then.

Oh, another thing I will be figuring out is how well everything seals and works with Maverick prob wires going through the door rather than the vent.  I didn't think about this at all with this project so I will try and come up with a better approach or I will simply just dedicate the probes to the smoker and fix them in place through the vent/new ducting and use foil to seal up the gaps that are made.  I have a strong feeling I'll be going this dedicated probe route.

Please feel free to give your thoughts and feedback.  I appreciate all of the input and ideas you guys come up with or help generate :)


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## Bearcarver (Jan 12, 2017)

Nice Job!!

However, I guess you didn't agree with me that it's more important to kick the heat over to the center of the smoker at the bottom, before it rises through the meat being smoked?

Also if you really think pushing it from right to left at the top is important, instead of at the bottom, why not just install a Top vent on the left, like Masterbuilt finally did with their Gen #2.5.

You could even put another identical vent in the top left, and then have two adjustable top vents. This wouldn't take any room from your smoker, and you could run your Maverick cables down either Vent.

Bear


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## tallbm (Jan 12, 2017)

Bearcarver said:


> Nice Job!!
> 
> However, I guess you didn't agree with me that it's more important to kick the heat over to the center of the smoker at the bottom, before it rises through the meat being smoked?
> 
> ...


Hi Bear.  

I don't disagree with your approach to kick the heat over at the bottom.  I have been using the following mod (ceramic tile) and can easily add the water pan like you do when I smoke.  I haven't been adding the water pan because the tile is fairly big but it wont hurt for me to try it.

(Ignore the drip pan and grates being in that position/configuration, this is just for storing and I will pull and arrange properly when I smoke)













DSC_8856[1].JPG



__ tallbm
__ Jan 12, 2017






My thought process was to get the duct in place so I could kind of mimic what you have described with the MES 2.5.

I like the idea of making another vent like you mention.  I'm going to wait to permanently modify the MES until after my warranty is up.  After the warranty is up anything I can do is fair game :)

With everything I have going right now I can go duct only, duct + ceramic tile, or duct + ceramic tile + water pan to hit all combinations.  I'm hoping some combination works.

The new controller should be here in 4 days so the weekend following that I will be able to try it out and see if it works better.  Man lots of stuff going on! :)


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## Bearcarver (Jan 12, 2017)

TallBM said:


> Hi Bear.
> 
> I don't disagree with your approach to kick the heat over at the bottom.  I have been using the following mod (ceramic tile) and can easily add the water pan like you do when I smoke.  I haven't been adding the water pan because the tile is fairly big but it wont hurt for me to try it.
> 
> ...


A long time ago, I tried the big piece of ceramic tile on the right of my MES 30, and I had big puffs of smoke coming out the top vent.

That MES 30 didn't have a Window, but I figured out that the heat from under the ceramic tile was trapped & was knocking the tile up & down with built up pressure.

I could have tilted it to avoid all the heat build up under it, but instead I elected to go with aluminum, because it's easier to cut & adjust, and works just as good.

If your ceramic tile is laying flat and tight against the back & right wall, the same could happen to you.

I don't see a good reason for the tile in there laying flat---Do you?

Like I said, the only thing I ever needed in my MES 40 Gen #1 was the adjustable heat deflector, and that worked perfectly. Easy too, as all you need is a piece of metal, and a folded up piece of foil for an adjustable prop on the left.

I could put a Temp probe on the right & on the left, and adjust the tilt of the plate to get both sides reading the same temp.

Bear


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## tallbm (Jan 12, 2017)

Bear this is what I can do with what I have at the moment.  I need to find a prop to angle the deflector.  As for now I have a little flap at the end I can bend up and down but not sure it will make any difference with the deflector already angled down.

I should be able to make it work close to what you have :)

(Edit: added image)













MetalFlap.jpg



__ tallbm
__ Jan 16, 2017


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## Bearcarver (Jan 13, 2017)

TallBM said:


> Bear this is what I can do with what I have at the moment.  I need to find a prop to angle the deflector.  As for now I have a little flap at the end I can bend up and down but not sure it will make any difference with the deflector already angled down.
> 
> I should be able to make it work close to what you have :)


At first I had a piece of aluminum bent into a "V" (upside-down), but I found a piece of scrap foil pan bent to the right size works great, and is easy to shape.

The right side of the deflector just rests on the top of the wire rack that holds the water pan, and the prop under the left end is in the water pan.

Bear


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## cflbob (Jan 13, 2017)

I just started researching why my MES has started running cooler than the thermostat is set for and found this thread.  I noticed this for the first time a couple of weeks ago while doing my first cold smoke with the external Masterbuilt smoke generator.  I was running a small load (1 pound) of salmon with the chamber set to 150, and noticed the meat probe on the side wall was reading 125 (the probe in the salmon was my remote reading ThermPro).  I turned up the thermostat to 175, the same 25 degrees as the difference between top and side.  A little while later the probe on the side said 150. 

I'm doing a few pounds of beef short ribs right now (with an umbrella to keep the rain off) and just noticed the temp difference again.  When I ran into Bear's post (#16, above):


> Generally speaking the biggest problem with the Gen #1 was the fact that the heating element is on the right side, and so is the top vent.
> So the heat would come from the right half of the smoker & run straight up the right side & out the top vent on the right.
> 
> That would make the right side hotter than the left.  I solved this years ago, by putting a piece of metal (Heat deflector) on the right side, just above the water pan in it's normal position. This would push the heat from the right to as far to the left as I wanted, by a simple adjustment to that heat deflector. I did this for 4 years, until I got my New Gen #2.5 MES.
> ...


I didn't even know I had a Gen 1, but this just seems like it has to be the root cause.  Mine is the 30" digital without a window and the controller on the back.  The heater and the vent are both on the right.

So if the problem is the heat rising straight to the vent, doesn't that say to close the vent?  Or at least don't run it wide open?  Can't recall how many times I've read on here to run it wide open. 

Is there a guide somewhere on how to tell the generations apart?  What to look for?  I have this 30" digital and a 30" analog, the one with a simple controller stuck in the side.  The analog model has some advantages, like a bigger chip tray which smoked for much more time than the digital.  It had to be checked a bit more closely because the thermostat is in that controller sticking out the side.  Over the course of the day, the temperature would drift. 

The analog smoker has the heater all across the bottom and the vent on the right, but it's just a small hole in the back, about half an inch diameter.  It sounds like it would have more even heat distribution, but since the only temperature readout is an analog thermometer stuck in the front, and the thermometer's not connected to that controller, we'd never notice this problem.


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## Bearcarver (Jan 13, 2017)

CFLBob said:


> I just started researching why my MES has started running cooler than the thermostat is set for and found this thread.  I noticed this for the first time a couple of weeks ago while doing my first cold smoke with the external Masterbuilt smoke generator.  I was running a small load (1 pound) of salmon with the chamber set to 150, and noticed the meat probe on the side wall was reading 125 (the probe in the salmon was my remote reading ThermPro).  I turned up the thermostat to 175, the same 25 degrees as the difference between top and side.  A little while later the probe on the side said 150.
> 
> I'm doing a few pounds of beef short ribs right now (with an umbrella to keep the rain off) and just noticed the temp difference again.  When I ran into Bear's post (#16, above):
> 
> ...


Closing the top vent is not a cure for the heat balance problem.

My heat deflector solves it in the Gen #1, and it sounds like you have the Gen #1.

Here (Below) is more on the MES units. One tells how to tell the various Generations apart:

*Masterbuilt Smokers (Bear's Thoughts & Findings)*

*MES Generation Number Recognition Pictures & Pics (Digital Units)*

Bear


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## cflbob (Jan 13, 2017)

Interesting.  My smoker looks like the Gen 1 30" except for one thing: the controller is rounded rather than square.  I got it at Cabela's last Christmas, if I recall correctly.  Also, the water pan is oval and the one in the picture looks round. 

Do you have a picture of your baffle handy?


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## Bearcarver (Jan 13, 2017)

CFLBob said:


> Interesting.  My smoker looks like the Gen 1 30" except for one thing: the controller is rounded rather than square.  I got it at Cabela's last Christmas, if I recall correctly.  Also, the water pan is oval and the one in the picture looks round.
> 
> Do you have a picture of your baffle handy?


The rounded controllers came out about 2010-2011.

The squared ones were earlier.

They're both Gen #1 MES.

Actually they are all oval water pans, but the MES 40 water pan is naturally bigger.

My Heat Deflector is seen in Post #24 above.

All it is a sheet of aluminum that lays there, but there is a prop on the left to raise & lower to adjust how much heat gets sent from right to left.

Bear


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## cflbob (Jan 13, 2017)

Bearcarver said:


> ...
> My Heat Deflector is seen in Post #24 above.
> 
> All it is a sheet of aluminum that lays there, but there is a prop on the left to raise & lower to adjust how much heat gets sent from right to left.
> ...


D'oh!  It's not like I hadn't just looked at that post.  Interesting idea.  Easy to grab a sheet of aluminum somewhere and give that a try.

Thanks


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## tallbm (Jan 16, 2017)

Well I have successfully reached 278 degrees with all of the modifications!  I smoked a ribeye roast yesterday and temps hit the proper high's I've never successfully hit before.

Now I don't know if it is a combination of everything added (Bear's deflector type setup + the vent duct) or any one thing in particular.  Also I need to make sure my results are repeatable.

I will play around with the configuration over my next few smokes and report back more details.  Also running the probes through the door caused no issue.  I will keep an eye on the door seal though to make sure it doesn't get worn down or permanently deformed.

I will post my ribeye roast in another thread with Qview once I get time this week.  It turned out well and I think I can improve it even more :)


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## cflbob (Jan 16, 2017)

Good to hear!  Very cool results.

This past Friday, I was smoking about 7 lbs. or beef short ribs, with the chamber set to 235.  My "meat probe" on the left wall was reading 190.  I kept increasing the thermostat until the chamber got to 225, and it was close to 265.  Definitely have to do something.

I was thinking of trying just a wrap of aluminum foil over the lowest rack, on the right side of the smoker, like Bear's.  It's really just a thinner aluminum baffle.


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## daveomak (Jan 16, 2017)

CFLBob said:


> Good to hear!  Very cool results.
> 
> This past Friday, I was smoking about 7 lbs. or beef short ribs, with the chamber set to 235.  My "meat probe" on the left wall was reading 190.  I kept increasing the thermostat until the chamber got to 225, and it was close to 265.  Definitely have to do something.
> 
> I was thinking of trying just a wrap of aluminum foil over the lowest rack, on the right side of the smoker, like Bear's.  It's really just a thinner aluminum baffle.


I moved the exhaust to the center of the MES 30 with an aluminum "tunnel"...   It helped my smokers uniform temps... 

The trouble, as I see it, with trying to get even temps is....   The air flow...  It's not homogenized...   there are currents...    The currents change with meat in the smoker...  where the meat is placed...   how many hunks of meat are in the smoker.... 

I figure, it ain't never gonna be perfect and live with it.....

If  you really want to get confused...   check the exhaust temp while checking the others... 













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__ daveomak
__ Dec 29, 2016


















3f61fe8a_exhtunnel2.jpg



__ daveomak
__ Dec 29, 2016


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## Bearcarver (Jan 16, 2017)

CFLBob said:


> Good to hear!  Very cool results.
> 
> This past Friday, I was smoking about 7 lbs. or beef short ribs, with the chamber set to 235.  My "meat probe" on the left wall was reading 190.  I kept increasing the thermostat until the chamber got to 225, and it was close to 265.  Definitely have to do something.
> 
> I was thinking of trying just a wrap of aluminum foil over the lowest rack, on the right side of the smoker, like Bear's.  It's really just a thinner aluminum baffle.


A bunch of aluminum foil would work for a test, but make sure you have the left end of that foil at least a little higher than the right, so the heat doesn't get trapped under the "Foil" deflector. raising & lowering the left side of that deflector will adjust the heat from right to left.

And Like I said, the only way to push the heat from right to left before it rises through the smoker is to do it at the bottom with a deflector. Anything you do up top will not change the movement of the heat at the bottom, or while it's rising through the meat.

Bear


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## cflbob (Jan 16, 2017)

Bear, did you have that piece of aluminum sheet lying around or did you buy it someplace?  Is it some sort of Home Depot part?  I don't have any sheets that size, and the only sheet I have is 1/8" thick anyway.  I wouldn't use 1/8 sheet in the smoker, it's too useful for other projects.


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## Bearcarver (Jan 17, 2017)

CFLBob said:


> Bear, did you have that piece of aluminum sheet lying around or did you buy it someplace?  Is it some sort of Home Depot part?  I don't have any sheets that size, and the only sheet I have is 1/8" thick anyway.  I wouldn't use 1/8 sheet in the smoker, it's too useful for other projects.


That's one of the Perks I get for having a Son who has his own Tower Corp.

The aluminum I used was a cut-off from the 12' top of a cable tray.

However Home Depot should have all kinds---Try the aluminum siding & flashing area.

Bear


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## sundown farms (Jan 17, 2017)

I have a MES 40-2.5 and used a 1/4 aluminum sheet pan from the restaurant supply as the bottom deflector. Fit is almost perfect but I had to cut the corners on one side and bend it down to fit over the water pan. The sheet pan fits fairly snugly although there are small gaps around the edges, especially at the glass door. It sits on top the water pan and the pan extends beyond it thereby splitting the rising hot air in half that I think makes for more dispersal of the hot air up the side opposite the heating element and the top exhaust port. The pan also fits in the dishwasher for cleanup.

I want to add the bent extension ducting like Bear has attached to the roof. But, it seems like with the bottom deflector the next greatest impact is the meat load and how they change the airflow. The roof ducting should mitigate those variances. Top rack and next to the door's glass is always the coolest area but the glass area will finally get close if I leave the door closed for +1 hour.


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## daveomak (Jan 17, 2017)

Sundown Farms said:


> I have a MES 40-2.5 and used a 1/4 aluminum sheet pan from the restaurant supply as the bottom deflector. Fit is almost perfect but I had to cut the corners on one side and bend it down to fit over the water pan. The sheet pan fits fairly snugly although there are small gaps around the edges, especially at the glass door. It sits on top the water pan and the pan extends beyond it thereby splitting the rising hot air in half that I think makes for more dispersal of the hot air up the side opposite the heating element and the top exhaust port. The pan also fits in the dishwasher for cleanup.
> 
> I want to add the bent extension ducting like Bear has attached to the roof. But, it seems like with the bottom deflector the next greatest impact is the meat load and how they change the airflow. The roof ducting should mitigate those variances. Top rack and next to the door's glass is always the coolest area but the glass area will finally get close if I leave the door closed for +1 hour.


If you trap too much heat in the bottom of the MES, it can warp and it can also burn up the electronics that are buried in the floor.....


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## Bearcarver (Jan 17, 2017)

Sundown Farms said:


> I have a MES 40-2.5 and used a 1/4 aluminum sheet pan from the restaurant supply as the bottom deflector. Fit is almost perfect but I had to cut the corners on one side and bend it down to fit over the water pan. The sheet pan fits fairly snugly although there are small gaps around the edges, especially at the glass door. It sits on top the water pan and the pan extends beyond it thereby splitting the rising hot air in half that I think makes for more dispersal of the hot air up the side opposite the heating element and the top exhaust port. The pan also fits in the dishwasher for cleanup.
> 
> *I want to add the bent extension ducting like Bear has attached to the roof.* But, it seems like with the bottom deflector the next greatest impact is the meat load and how they change the airflow. The roof ducting should mitigate those variances. Top rack and next to the door's glass is always the coolest area but the glass area will finally get close if I leave the door closed for +1 hour.


I don't do any ducting at the top. All I do in my MES Gen #1 is the heat deflector at the bottom, and it shouldn't fit too tight, and the left side should be higher than the right side. None of this is needed in my MES Gen #2.5.

And like Dave & I have both said, you don't want to trap heat down there---It could do damage to the Smoker.

Bear


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## floridasteve (Jan 20, 2017)

Just had a thought.  I wonder if the mes cabnet temp sensor and the mes meat probe had have the same parameters.  If so, one could just switch the wires and put the meat probe wherever you want.  Or, if you could remove the cabinet sensor, extent its wires and make a dohicky to hang it wherever you want?


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## sigmo (Jan 20, 2017)

I know this is long, so bear with me if you want to:

It probably isn't a bad assumption to think that they'd use the same type of sensor element for both of these probes since it would simplify the design of the controller.  So they might both be thermistors of the same type.

And it's not a terrible idea to have a moveable sensor for the controller so that you could force the unit to maintain the temperature at your desired test point to be what you want.

But you would want to be very cautious with any such modification and the implementation of it.

It's important to realize that the position, shape, thermal time constant, etc., of the sensor that reports back to the controller so it can control the power to the heater are all part of the design of the system.

The position of their sensor, right above the heating element, and its size and speed of response have all been "tuned" along with the program in the controller to achieve the response that the designers want.

We can imagine that the sensor, right where they have it, "sees" the heat coming up off of the heating element fairly directly.  This causes the system to shut off the heater sooner than it would if the sensor was located somewhere farther from the heating element, and out of the direct path of warm air rising up from it.  So the speed of cycling on and off of the heating element is likely faster with the sensor right where it is than it would be if you placed the sensor farther away from the heating element.

If you place the sensor in some place that you feel is more representative of the actual temperatures that the meat is experiencing, that has the advantage of forcing the smoker to drive that temperature to the setpoint you've programmed.  And this seems, at first glance, to be a good thing.

But what you have to remember is that this could cause a dangerous situation, and further, it's not necessarily what you really want in terms of making your cooking match what you see in various recipes.

As an extreme example:

Let's say we swap the meat probe and the controller sensor on one of these smokers.

Now, we want the unit to control the temperature that our pork butt is actually experiencing.  So we put the meat probe fairly near to the pork butt, and fire up the smoker.

Right away, the heating element comes on full blast.  But it stays on for a very long time because the sensor is near to the pork butt, and the cold temperature of that butt, along with the moisture in it, creates an area around it that is fairly cool compared to areas in the smoker farther from the butt.

So the temperatures seen by the hottest places in the smoker (presumably down near the heating element, and other areas farther from the big piece of meat) end up being far higher than the setpoint we've punched into the controller.  The controller thinks it needs to keep the heater on, yet the temperatures in the hottest parts of the smoker may be dangerously high. High enough to start decomposing the foam insulation in the back or sides of the smoker nearest to the heating element.

Further, even if the temperatures don't become dangerous, the heater may cycle on and off very slowly.  Perhaps staying on for half an hour or an hour at first before our probe "sees" the temperature we wanted.  And then, once it does "see" that temperature, so much heat might be stored in the system that the heating element will now remain off for a very long time before things cool down enough to cause it to cycle on again.

Cooking recipes take into account the phenomenon of the actual air temperature right near the big thing being cooked taking a long time to come up to match the "oven temperature".

With a so-called convection oven (misnamed IMO because they use the OPPOSITE of convection, and instead rely on a fan to actively circulate the air). things cook faster than in a "normal" oven.  This is because the active fan-stirring of the air gives you a more uniform temperature throughout the oven and constantly forces this "proper temperature" air over the item being cooked.  So it doesn't have this layer of cool air surrounding it.  Instead, it's continuously exposed to air that is closer to the actual oven temperature setting.

So you have to consider the effects on cooking time in all of this.

Further, from a control-system tuning point of view, consider this:

In many laboratory drying ovens, incubators, etc., I have seen the temperature sensors placed in the direct path of the heated air coming off of the heating elements.  At first, I thought this was silly because everyone knows that you don't put your home heating system thermostat right above a heat register, or it'll shut off too early and never get the main living space up to the correct temperature.

But there is a method to their madness!  It's part of how they "tune" the controller that maintains the oven's temperature.  It effectively speeds the response of the system, and lessens the amount of temperature swing between the "ON" and "OFF" parts of the cycle.  It also acts as a safety feature because although parts of the oven are, indeed "too cool", we know that no part of the oven is ever "too hot".  And that's the tradeoff they make.

As we cook something in an oven or smoker (or as we dry samples in a laboratory drying oven), we do NOT want any part of the food or samples to get above the oven senpoint temperature.  Food can burn or dry out, and samples might go over the upper temperature limit set forth in a particular analytical method, and thus give invalid results because you drove off things that would not be volatile if you stayed below the prescribed upper temperature limit.

So always keep in mind that unless you're prepared to reprogram the controller and carefully troubleshoot all of the side-effects of tampering with the factory design, you probably should keep things pretty much as they are.

The easy method people have used on here is to simply set the controller to a temperature a bit above what you normally would if you want a higher cooking temperature.  And they base this "offset" on what they read with their moveable probe thermometers/loggers.  Still, they need to keep in mind that many of the recipes we see are based on an unmodified smoker that was set using the factory control system with no adjustments or modifications.  And measuring the temperature in one particular place may not really be telling us the whole story.

Still, I do sympathize with people thinking that their smoker's actual temperature is incorrect.  And clearly, these inexpensive smokers don't have the best possible control systems, and I'm sure some are way off.  Just be careful and realize that measuring the actual temperatures in an oven is a bit more involved than we might think.  There can be HUGE variations in temperature from one place to another, especially if there is no active stirring of the air.  I've seen laboratory ovens with 15 degrees C (27 degrees F) of difference between probes placed several INCHES apart!  I've had PhD chemists complain to me that my monitoring system was way off due to this, only to later prove to them that the system, and a number of separate probes were, in fact, all in agreement with a NIST traceable thermometer to within 1/100th of a degree C!  Indeed, it was simply variations in temperature within small distances in these ovens that was real.

So we need to be extremely diligent in our assessment of temperature accuracy.  What we see with our fancy external thermometer or data logger may well be true.  But only for the very place and time where it's probe happened to be.  So I don't like to be too quick to impugn the accuracy of the factory probes or controllers in any oven or smoker.

But again, I also know they aren't perfect.  And for what these systems cost, I'm sure people get real lemons.  My MES's sensor/controller is quite non-linear.  And while it's very accurate at room temperature, it gets farther and farther off as we get up into cooking temperatures.  But so far, I have found that if I set the unit to the temperature the recipe calls for, even though I've proven that its temperature sensor is not linear, and is off, perhaps 20 degrees at 225, the food cooks to the correct internal temperatures in times that match up pretty well with what other people post in their recipes and other posts on here.

Also, we all find that we have to make trial-and-error adjustments to our recipes anyhow because our humidity, ambient temperature, elevation, etc., all play into this.  So none of it is exact.  Our smoker calibration is just one of the variables we have to account for with our trial and error.

What I DO want to be dead-on is my meat probe, though!  And fortunately, in my MES, the meat probe is within a degree or so over the whole range.  Maybe I lucked out.  I don't know.  Maybe the meat probes are different.  And maybe, just maybe, the bizarre non-linear calibration of my MES's controller sensor was done on purpose to make the actual response in the main part of the cooking chamber end up being correct.  Perhaps that's giving MB too much credit.  But the fact is, I just don't really know.

But because my MES's meat probe IS so accurate, I can use it in different places in the chamber to see what the temperature is doing, and then make manual adjustments to the controller's setpoint to get what I want during different parts of a smoke, or just to keep an eye on it.

I once placed the meat probe just below where a large pork butt was being smoked, suspended in some paper clips so it was about an inch below the butt.  It was very interesting to look at that temperature and see it go up very slowly during the first hours of the smoke.  I didn't change anything based on those readings, but it was interesting to see how the temperature right there stayed fairly low, initially, probably in part because of the moisture on the surface of the butt.  Then, as it formed a pellicle or bark, the temperature right under the butt finally started to rise.  It's interesting information.  Not because I wanted to adjust the temperature of the smoker, but because it helped show me what the temperature near the butt was actually doing during a typical smoke in a non-stirred oven environment.

It's nice to have a known accurate, moveable probe that you can use to tell you what's going on in different places within our smokers.  Just don't be too quick to think you need to change things.  Millions of non-technical people make millions of great meals in their factory-stock smokers.  Ignorance is bliss, I guess.

Still, I'm a tinkerer, and for me, and clearly a lot of us on this forum, we LOVE to play with all of this, and we want to understand what's going on, and we want to optimize things.  And really, that is a big part of the fun in all of this. And I do not dispute that some of these smokers really do have calibration problems.

In the spirit of experimentation, hobbyist enjoyment, and just plain Smoker Nerdism, I am planning a serious modification of my MES, using different sensors, and a stirring fan from a convection oven.  So I am right with you in this!

But I will leave the snap-disk safety cut-off in the circuit that feeds the heating element.

And I've already modified the air intake and heating element area with different baffling to get better pellet burning along with heat and smoke distribution in the smoker.  But I have made sure that some of the heat from the heating element still has a good "straight shot" up to the sensor.  I don't want to circumvent the control system's tuning too much until I do the full modifications I have planned.  At that point, a lot of things will change, particularly because of the stirring fan.

What I've got in mind is to use the stirring fan to keep the temperature and smoke fairly even throughout the chamber.  And I'll also use a different sensor to inform the controller of the oven temperature as well as a couple of "free to move" sensors to give me information about what the temperature is doing in selected places within the smoker.  And finally, I've got a new meat probe as well because I want the controller (and me) to be able to keep track of the meat probe temp, and I have no interface that can read the factory style thermistors.

Hopefully, as I do this, it will yield some interesting and useful information about what the temperatures really do in different places inside of one of these smokers. Two of the thermocouple sensors I got have alligator clips so you can easily move them and hang them in different places.  They came from the manufacturer that way!  How cool is that?

I love experimentation.  Just be safe, and consider the consequences of various modifications.

All of this is great fun, IMO!


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## sundown farms (Jan 22, 2017)

Sigmo - Thank you for taking the time to share so many significant thoughts. I like checking the temps inside the MES and have found there are so many things beyond the design of the MES that cause variations in every smoke that the thing to do is relax, set it up like the last time the meat was great and enjoy the day.  Thanks again!!!


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## tallbm (Feb 14, 2017)

Sigmo said:


> What I've got in mind is to use the stirring fan to keep the temperature and smoke fairly even throughout the chamber.  And I'll also use a different sensor to inform the controller of the oven temperature as well as a couple of "free to move" sensors to give me information about what the temperature is doing in selected places within the smoker.  And finally, I've got a new meat probe as well because I want the controller (and me) to be able to keep track of the meat probe temp, and I have no interface that can read the factory style thermistors.
> 
> Hopefully, as I do this, it will yield some interesting and useful information about what the temperatures really do in different places inside of one of these smokers. Two of the thermocouple sensors I got have alligator clips so you can easily move them and hang them in different places.  They came from the manufacturer that way!  How cool is that?
> 
> ...


I've already PID'ed a used Gen2 MES I got for dirt cheap andI think I'm about to reach the fan part of my journey soon.  I'm finding that the PID prob (which is small) is getting hidden behind meat and pans and such and not reading as well as the Maverick probe (much much larger).  If airflow was more even then it wouldn't matter where I put the PID probe.

I've been researching convection ovens and such and I think I can create a makeshift convection type setup.  I'm looking at the following mod that would include a fan for convection type air flow and the mailbox mod with ANMPS spliced in:

- 3 inch duct Tee













41jj4paDMaL._SS100_.jpg



__ tallbm
__ Feb 14, 2017






-3200RPM 80mm (just over 3 inches) Fan













41qA1LtDf4L._SS100_.jpg



__ tallbm
__ Feb 14, 2017






-Mailbox mod I already have in place













2j17cdd.jpg



__ tallbm
__ Jan 8, 2017






Basically hook the Tee into the MES.

Hook the fan to the back end of the Tee.

Hook the mailbox mod to the underside of the Tee

I would end up making something like the following photoshop'ed image:













FanModIdea.png



__ tallbm
__ Feb 14, 2017






The only thing I am lacking is a concrete calculation of how much fan and speed I need/want for the volume of air I need to turn over in the MES40.  I can find bits and pieces of info on convection cure oven, hvac temp management, and dimensions of convection oven parts and oven sizes along with fan speeds (RPMs).  However I cannot find a definite statement of "here is how you calculate fan size and speed for air volume" of a convection oven.

Sigmo, maybe you have some insight?

The best I can do is try to replicate what convection ovens are doing as best as I can within the confines of the MES dimensions and not completely hacking up the smoker to use an actual convection oven fan.

[Edited to strike through because CFM is probably the metric I need to work with not RPM, learned it here https://ftiinc.org/4-best-features-make-oven-airflow-better/]

So a 3200 RPM fan with a roughly 3 inch diameter fastened to 3 inch ducting is about the best I could do within the limitations of the MES in an attempt to mimic 150mm ( almost 6 inches) 4000 RPM convection oven fans I looked up.  Most of those fans operate on a low setting of 900-1000 RPM's so I'm hoping that 3200 RPM out of a 3 inch fan would be roughly equivalent to the min speeds of the 6 inch convection fans or fall between the min and max speeds for those same convection fans.

Ok the MES40 has no more than 24 cubic foot of space (calculated from outer dimensions, couldn't find inner dimensions and I'm not near to measure).

So the fan I looked up is a 22 CFM so it should pump 22 cubic feet of air per minute.  So every minute the air could technically circulate in the MES (barring issues bouncing around, etc.).

Now I just need to figure out the desired circulation per minute for cooking.   

That's the best I have so far.  Any input from the community would be appreciated. Thanks :)


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## floridasteve (Feb 14, 2017)

The problem I see with this is that you are introducing cold air to the box, as opposed as to recirculating the existing air.  This could make it hard to maintain higher temps inside the box.


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## tallbm (Feb 15, 2017)

FloridaSteve said:


> The problem I see with this is that you are introducing cold air to the box, as opposed as to recirculating the existing air. This could make it hard to maintain higher temps inside the box.


Good point. Thanks for waking me up hahaha.  

I got so carried away with researching the ins and outs of circulating air that I totally failed to keep that detail in mind!

Well I did see an example on the internet of a fan simply installed into the smoker with the motor on the outside, see image below:













IMGP8431s.jpg



__ tallbm
__ Feb 15, 2017


















IMGP8435s.jpg



__ tallbm
__ Feb 15, 2017


















IMGP8432s.jpg



__ tallbm
__ Feb 15, 2017






With that setup I think I can apply a bit more of what I have been learning and see what/if anything is possible.  I like how simple that mod seems but I have to dig into it a bit more.

Please feel free to poke any obvious holes into these ideas or offer solutions.  Thanks for the input!


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## dr k (Feb 15, 2017)

CAM00483.jpg



__ dr k
__ Feb 15, 2017





My cables and probes clip/lay/hang/suspend from the rack above the meat so no obstruction. I made rtv silicone pucks, the clips the probes came with are clipped on the underside of the rack above the food. Use  wooden clothes pins. Get probes/cables away from your food that aren't in the food. Dont let finding a home for your chamber probes be your demise. 
-Kurt


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## tallbm (Feb 15, 2017)

Dr K said:


> CAM00483.jpg
> 
> 
> 
> ...


Thanks for posting your solution.  Maybe i can take a bigger champagne cork and put the little probe through it and pull through some excess chord so I can then let it dangle through a rack above meat.  I will try and mimic your design with a cork and see what happens. 

So far I've tried to utilize a little flue tape and a small stainless steel hook to try and rig up a hanging mechanism for my PID smoker probe.  The squeeze clip is just not working out and is barely small enough for the probe to fit in it.   The PID probe is the small and doesn't want to cooperate so well with my make shift hook addition. I will look into the alligator clips as well. Thank goodness the maverick probe has no issues.


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## sigmo (Feb 17, 2017)

FloridaSteve said:


> The problem I see with this is that you are introducing cold air to the box, as opposed as to recirculating the existing air. This could make it hard to maintain higher temps inside the box.


That's right.

The way I am thinking about all of this is that the stirring/circulating of the air _within_ the smoker is independent of the air flow _through_ the smoker.

So, as TallBM points out in a later post, what we want (for circulating the air within the smoker) is a draft inducer type fan which stirs the air within the smoker itself, but which does not directly affect the flow of air _through_ the smoker.  This is exactly the type of fan I've got and am considering installing into my MES 40.

The airflow through the smoker (the "draft", if you will) can then remain the same as it always was, being driven entirely by the convection (warm, lower-density air rising due to its buoyancy with respect to cooler, denser air).  Or, a separate forced-draft system can be used to force air through the smoker if desired/needed.

I think it's best to think of these two air-flows as being separate, and separately controlled or adjusted.

Quote:


TallBM said:


> Good point. Thanks for waking me up hahaha.
> 
> I got so carried away with researching the ins and outs of circulating air that I totally failed to keep that detail in mind!
> 
> ...


That fan is very much like the one I got to try in my smoker.  I got a used fan meant for a convection oven.

(Darn how I hate that term:  "Convection Oven")!

Convection is the effect where air circulates due to differences in density, usually due to temperature differences.  As you heat air up, it wants to expand.  If the pressure is kept the same, it "swells up" if you will.  Naturally, when the air expands, its density goes down because the same number of molecules are now occupying more space.  So any given volume has less molecules and therefore less mass.  This is why a hot air balloon has lift or buoyancy.

Anyhow, it is this effect that causes convection.

But in a "convection oven", a fan is used to stir the air, NOT convection!  So the terminology is completely backwards and counterproductive, creating more confusion among people, which is a real crime IMO.  Whoever coined the term and applied it to a fan-forced oven should be ashamed of themselves.

Anyhow, I got a used fan from a "convection oven".  They're designed for just the kind of use we're proposing here.  The design uses a long shaft to separate the "hot end" (the fan and end of the shaft that is inside of the oven or smoker) from the "cool end" (the end where the bearings and motor are - outside of the oven or smoker).

There is also a separate, smaller set of fan blades back near the motor and bearings to help keep it even cooler and to draw heat that travels down the shaft out of the shaft before it enters the front set of bearings.  This all helps allow such a fan to last a long time despite the main fan blades being inside of a very hot oven.

I need to drill a hole through both the inside and outside layers of the smoker body, and through the insulation between those layers.  I want the hole to be small so that I don't create a puncture in the oven and an unwanted path for airflow into or out of the oven.  But I also don't want the shaft to rub on the inside of the holes, so that's a tradeoff.  It'll never be perfect.  I also need to build an enclosure around the fan motor to protect it from the elements and to provide a grounded safety "cage" around the open electrical contacts on my fan's motor.  But I do want the fan motor to be able to stay cool, so I may put some ventilation openings on the bottom of its enclosure, and make it out of aluminum for best heat transfer to the outside.

The power wiring for this fan will enter this safety/protection enclosure through a normal electrical box fitting or conduit gland bushing, etc.  Electrical safety is a concern as is physical protection of the motor.

I'm still considering the best placement of the little stirring fan.  I want it to blow air over the heating element of the smoker to some degree and stir the entire cabinet as well as possible.  We'll never have the kind of fancy airflow control like what is mentioned in that article you linked to, but I'm hoping it can be made considerably better than what I have right now.

I'd also prefer to place some kind of protective screen over the fan blades inside of the smoker to prevent accidental contact with them either by food or my fingers!  The placement of the little fan will need to be such that it doesn't interfere with the grates, etc., too.

I also think I may set up my control system to cycle the fan on and off rather than leaving it on 100% of the time.  In my home "convection oven", the fan switches on and off.  It may cycle on and off with power to a heating element that surrounds the fan, but in any case, it's not on all of the time.   It cycles frequently enough, though, that it probably does keep the air well stirred.

It may be that running it 100% of the time is too much, drying things out or making things cook too rapidly.  But in any case, having the ability to adjust (or have the controller adjust) the fan's duty cycle will let me play with that to get good stirring without having it be too much.  I think there are good reasons for not directly controlling its speed, but instead cycling it on and off.  And since that's easy enough to do, I plan on doing it that way.  As that article points out, the hot air can be made to sweep the cold air out from around the "product" and then left there for its heat to soak in for a while, then stirred again, etc.

One of the advertising sites I see for a manufacturer of these commercial smokehouses uses a set of dampers operated by a motor drive, that constantly move to make the "breakpoint" they mention move from place to place within the smokehouse.  They make the same point about sweeping the cool air away from the product, replacing it with the heated air, then letting the heat from that hot air soak into the product in that particular place while the smokehouse moves the breakpoint on to another place within the cooking chamber.

In our case, the chamber is small (like my home convection oven), so simply cycling the fan on and off probably stirs the air within the whole volume all at once, then, while the fan is off, you get that soaking-in phase.  I sort of get the feeling that they want to periodically stir the air to displace the layer of cold air that builds up around the "product", and replace it with hot air, but then they let it rest that way for a short time, then repeat that process.  Perhaps this gives less drying of the product yet achieves the even, faster cooking.  So I do think this is something to consider.

My hope is to get even cooking and smoke throughout the whole chamber regardless of how I load the "product" in.  Of course nothing is perfect, and I think it'll still be wise to arrange chunks of "product" in ways that lend themselves to good airflow around and between them to help keep things even.  But having a fan stirring the mix every so often should be a LOT better than just letting the air sit stagnant in the smoker.

Of course, now we get to the other airflow.  That's the air flowing through the smoker.

My feeling is that it will always be beneficial to be able to control that airflow separately from the stirring airflow.  And we'll have that by using a stirring fan as you've shown in your pictures above.

I figure the actual "convection" or "draft" will still suffice to let us use our mailbox type smoke generators.  The smoke generator won't even know if the stirring fan is on or off.  It'll behave, and the draft will be the same as it always has been.

But I'm not currently using a mailbox mod.  I just put an AMNPS inside the smoker, and have the inside ducting/baffling set up to draw air over the AMNPS by convection up and out of the vent at the top of the smoker.

I won't be able to do that once I have the stirring fan in place. At least not without some kind of modification.  I think the best will be to move the AMNPS outside of the smoker, into a mailbox mod setup, so that the airflow over the pellets will be independent of the air movement inside of the smoker.  So that will all have to happen at the same time as my installation of the stirring fan.

I guess I could do something to shield the AMNPS from the blowing of the stirring fan, and maybe continue to use it inside of the smoker.  But there are other good reasons to move the smoke generator completely outside of the smoker, too, and I've been planning on doing a mailbox mod anyhow, so I'll likely go that route ultimately.

Now, we also get to the idea of using a fan to force or regulate the airflow through the smoker.  And, perhaps a separate fan or way to regulate the combustion air over our burning wood chips or pellets, etc.  you could end up with three fans if you wanted to control all three air flows separately!

But simply adjusting the position of the damper at the top vent of the smoker, and playing with the positions and sizes of the air inlet openings in a mailbox will still work just as it does in a non-stirred smoker.  So actively controlling the draft and combustion air can be played with as separate projects.

I tend to think that having control over all of that would be handy, though.  For doing jerky, for example, one might run the stirring fan constantly, and force more air through the smoker than normal to aid in drying it during the later phases of the process.  Yet we'd want to keep the smoke density at some ideal level the whole time, so having independent control of all three air flows could come in handy there.  Or for crisping the skin on a turkey or chicken, we might want to do the same kind of thing.  On the other hand, for a lot of other smoking, we may not want so much air flow through the smoker so that things stay more moist, etc.

You could end up with a lot of control, but you'd then have to play with things to figure out what works the best.  And we'd be on our own with all of that because none of the recipes you'd find would be tailored for that kind of setup.

But again, these smokers work pretty well right out of the box, or with some simple modifications.  So playing with all of this is something I'd be doing, in great part, just because it's a fun part of the "hobby", not because it's necessary to get good smoked food.  The last pulled pork and the last batch of smoked pecans that I did came out just great with things just as they already are.  So I have to admit that this whole exercise would be mostly just smoker-nerdism!


Dr K said:


> CAM00483.jpg
> 
> 
> 
> ...


Excellent points, and I like the high-temp RTV pucks!

You really don't need a bunch of wires and probes interfering with the use of the smoker.  That looks like an easy way to move things around when you need to, yet keep them in place.


TallBM said:


> Thanks for posting your solution.  Maybe i can take a bigger champagne cork and put the little probe through it and pull through some excess chord so I can then let it dangle through a rack above meat.  I will try and mimic your design with a cork and see what happens.
> 
> So far I've tried to utilize a little flue tape and a small stainless steel hook to try and rig up a hanging mechanism for my PID smoker probe.  The squeeze clip is just not working out and is barely small enough for the probe to fit in it.   The PID probe is the small and doesn't want to cooperate so well with my make shift hook addition. I will look into the alligator clips as well. Thank goodness the maverick probe has no issues.


The probes I bought to use for my proposed project came from Auberins.

I got all type K thermocouples because that's the kind of inputs I had available for my controller.  I'll have to use type K thermocouple extension wire for them, though, which is an issue, but I have a bunch of that on hand now.  But the point is that I found three different types of probes.

A meat probe, which is just like most meat probes with the probe tube bent over at a 90° angle and a sharp point on the end.

Air probes that have alligator clips already on them so I can move them around to monitor various points inside of the smoker.

A bulkhead-mount probe that I'll mount through the smoker wall to be the main sensor for the PID control of the smoker temperature.

As with the OEM setup, I'll likely put that sensor in a position above the heating element and not too far up from it so that it shows me a "worst case" highest temperature for fast response and greatest safety.  I can log the temperature at the other two alligator clip probes and even work them into the control algorithm if I want, too.  Being able to see how far the alligator clip probes are from the main sensor can be used to control the duty cycle of the circulating fan, too.

It should be interesting to see how uneven the temperatures are without the fan operating and then see how much that can be helped and how much fan operation is needed to achieve that.

When I did the last pork butt, I again placed the smoker's meat probe below the butt, hanging in paper clips from the rack about an inch below the butt.  And I wrote down what that temperature read at various points in the run.  I only inserted the probe into the meat after it had cooked for quite some time so I was sure the outside was pasteurized, and then, only after probing with a separate meat thermometer showed that the IT was getting high enough to warrant constant surveillance.  So I do have the data for most of the run.

But I can only go by the smoker's own probe to know what the smoker's air temperature was supposed to be at all of those times.  So I'd just have to assume that it was holding the set temperature.  Which it may well have been.  The butt came out great for whatever that's worth.  ;)

Having some separate, independent probes that I can place as I wish should prove informative.  It would be neat to make a run without the fan stirring, and then try to keep everything the same, but use the stirring fan, and see how a probe placed near the meat responds in both cases.  But there are a lot of uncontrolled variables in such an experiment.  Still, it'd be fun.

I'm waiting for good weather here to take on this project because I'll need to run cabling for the probes to where I plan to have the controller.  And I'll need to take the smoker's back off and do some kludging for the fan and the probes as well as to bring out the power feed for the heating element so I can control it.  And I'd like to do that all when I'll have good weather for it.

So for now, I'm just accumulating parts and pieces and trying to think of how to do it best.


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## tallbm (Feb 17, 2017)

Sigmo said:


> That's right.
> 
> The way I am thinking about all of this is that the stirring/circulating of the air _within_ the smoker is independent of the air flow _through_ the smoker.
> 
> ...


Sigmo you posted the exact kind of info I was looking for. 

For my fan mod I have bought a "convection" oven motor and fan blade like you have done.

Also I purchased the following fan controller so I could wire it in and go from Zero circulation to the Max circulation or anywhere in between.  I think I will take a page out of the Traeger pellet grill smoking book and turn the fan to a LOW constant RPM so I get continuous stirring but hopefully slow enough to remove cool air and still allow heat from hot air to soak into the meat.  Only playing around will let me know but as you allude to, things work pretty well as they are with no fan so I think just adding a little stirring will go a long way and I have the option to go hardcore stirring for jerky!

Fan Speed Controller I bought and handles a max of 15A over 120V:














41vP86cu7vL._SY90_.jpg



__ tallbm
__ Feb 17, 2017






I have the mailbox mod so no issue with the air flow to the smoke generator and I believe the draft from the heat of the element will still pull air with no issue. I"m just going to live with my current vent setup so here is a breakdown of all 3 of my air flows:

Breakpoint and Vent - I'm living with what is there, it seems to be OK and I think it will do well enough
Draft into smoker - pulled from heat of element through my mailbox mod which will also suck the smoke in as it does today so no changes from my current setup there
Stirring - Frigidaire 316136300 Range/Stove/Oven Fan Motor  and a fan blade for it.  I plan to drill into the box and attach from the outside as you mention.  Placement is still up in the air but I'm thinking in the back and out of the way would be great and also putting perpendicular to the Draft from the mailbox mod would be wise so that I don't chance blowing that draft back or interrupting it much at higher fan speeds for jerky and such.
As for probes my current PID on my Gen2 build came with the box mount type probe so it is small and get's blocked easily.  I'm working on getting it setup to be easily moved.  This smoker is may experimental smoker I'm giving away to my parents after I finish running it through it's paces to ensure it is good to go.

The probes for MY Gen1 smoker that I will be modding are all Hybrid probs (at least 3 of the 4 probes are).  But like you I am still gathering parts for that smoker overhaul as the HeaterMeter/LinkMeter PCB boards are on back order and should be in over the next couple of weeks. I still need to figure out a project box for that setup as well but I figure I would wire it up into a simple Gladware container and then understand the requirements for the project box after that :)

Thanks for the input and please keep us all posted on your fan mods and adventures.  I will surely do the same :)


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## sigmo (Feb 17, 2017)

TallBM said:


> Sigmo you posted the exact kind of info I was looking for.
> 
> For my fan mod I have bought a "convection" oven motor and fan blade like you have done.
> 
> ...


That looks excellent.

That fan is virtually identical to the one I got.  I think it should work very well.

I'm torn between adjusting the speed of the fan versus cycling it on and off.  I could do either with the controller system I'm going to use depending on the type of output I choose.  On the one hand, having the fan run constantly at a low speed seems like it would keep things more evenly stirred and be more consistent.

But on the other hand, running it full blast, but only intermittently might have some advantages to consider:

1.  With the fan running full bore, you'd get a more vigorous blast of wind inside the chamber, so it would "break through" any stratification and force its way around more difficult paths better.  So that might give better "reach" into the corners, nooks, and crannies.

2.  If the bearings gum up a bit, starting the fan full bore will tend to break past that crusty-bearing resistance and allow the fan to start more reliably after things get more gummed up with smoke residue.

3.  There may be some method to their madness in the commercial convection ovens where they do seem to run the fan full blast, but intermittently.  Perhaps the "blast and soak" has some cooking advantages over the more gentle-continuous stirring of the air.  I tend to think that it may be good to have high air flow to better "scour" the cool air away from the product every so often lest we get zones of stratified air that are hard to penetrate with a gentler blowing action.

I've been amazed at how badly the air in laboratory ovens stratifies.  Having huge temperature differentials over distances of only a few inches points out how resistant these stratified zones must be to stirring from normal convection.  They're sort of like the stark layers you get with a temperature inversion.   Still, any active stirring has got to be a LOT better than just letting things be stagnant and stratified.  I just like the idea of really blasting it every so often to break through and destroy any of these "barriers" that might develop.

The problem becomes how to achieve this intermittent "full-on/full-off" mode without using a fancy programmable controller or microcontroller, etc.  For the major manufacturers of convection ovens or smokehouses, it's no problem, and is likely even cheaper to implement than a variable speed control.  In my home convection oven, I can hear a mechanical relay kick on and off as the stirring fan comes on and off.  So since they've already got a microcontroller running everything, it's cheap and easy for them to just add a cheap mechanical relay and use a digital output on the controller to run it.  So they may be doing it just because they're being cheap!

Also, they may be cycling the fan on and off simply because it's cheap and easy to just wire the fan in parallel with the circular heating element that surrounds that fan.  They just cycle the heater on and off as needed, and the fan just goes along for the ride!

So I don't really know if they're cycling it full-on/full-off on purpose because they think it will work better that way, or if they're doing it that way just because that's a cheaper option for them than using a variable speed setup.  Beats me!

Again, I can see pros and cons to doing it both ways, so I'll be interested to hear how the variable speed control works for you.  That looks like a good unit, and the price is right, too!  It will make it easy to experiment and adjust things easily to get what you want.  And I agree that it may well be that just a bit of gentle stirring will likely make a big difference in uniformity without drying out the meat too quickly.  But you'll have the option to blast it hard for jerky or crisping, etc. 

You make a good point about not letting the stirring fan accidentally blast air towards the air inlet, thus, perhaps, causing backwards flow or reduced draft, etc.  The placement of the fan and maybe some kind of baffling will need to be considered to keep the fan from affecting the "draft" through the system!  Ideally, the stirring won't affect the draft at all.  But it would be all too easy to get some kind of accidental pulling or pushing of the draft air!  So we'll have to be careful with that, for sure!  And that might be more of an issue when the fan is running full bore, too.  So that's something I'll need to watch out for.

The way the blades on mine look (and I think it'll be identical to yours), it must pull air inwards at the center of the blade disk.  Then it slings it outwards in all directions.

This works great with the circular heating element that surrounds the fan in my actual convection oven.  And in our smokers, I think it might work very well, too.  But since air will go out in all directions from the fan when it's on, some of that might end up aimed right at the normal air inlet to the smoker.  So some kind of baffle might need to be installed so that the inlet port doesn't see any increased (or decreased) pressure when the fan is running.  Ideally, the inlet port will see the "average" air pressure inside of the smoker so it will draft normally with or without the fan running.

You might not need to worry as much about your current PID's sensor being "blocked" once you're running the stirring fan.  Ideally, having things stirred will give us better control since the controller's sensor will "see" a better representation of the overall temperature in the smoker.  You still want things to be safe with the fan turned off, of course.  So I plan to mount my "main" sensor more or less where the manufacturer's sensor is located.  But I anticipate better control with the fan stirring taking place.  I just want it to be safe if the fan is off on purpose or fails for some reason.

There's a lot to be considered in all of this!

We'll both have to keep posting as we get further along with these projects so we can share our thoughts and experiences.  This forum is great.  :)


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## tallbm (Feb 17, 2017)

Sigmo we have some fun times ahead of us for sure.  I have a feeling it will work out well.  I believe the Traeger pellet gril has a fan that runs like 2.5 RPM for their smokers.  If that stirs and keeps their pellets going then I"m sure anything we do will be icing on the cake :)


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## sigmo (Feb 18, 2017)

TallBM said:


> Sigmo we have some fun times ahead of us for sure.  I have a feeling it will work out well.  I believe the Traeger pellet gril has a fan that runs like 2.5 RPM for their smokers.  If that stirs and keeps their pellets going then I"m sure anything we do will be icing on the cake :)


You're right!

And you bring up another point, too.  A stirring fan also "stokes" the pellets.  Since I have had to resort to heroic measures to keep pellets burning at my elevation, a bit of extra airflow over a smoke generator that's inside of the smoker might not be a bad thing for me.  But it would have to be very gentle or else it'd be way too much of a good thing!  I can see how a very slow stirring fan would help with uniformity of temperature and smoke and also help keep pellets burning reliably.

I can't wait for a long stretch of good weather when I have some time off to pursue this project further.  I guess I can run some of the wiring ahead of time, but I've had a lot on my plate (besides great smoked meat) lately, and just haven't gotten around to all of that.

Since I'm going to use a fancy programmable automation controller for this, and since that same controller will be doing other chores around the house, I will keep it in an office room.  But that means that the thermocouple extension wire as well as other sensor cables and control wiring will need to be run from that room out to an outdoor connection box at the back porch where the smoker lives.  I've got the wire and connectors, etc.  But I think I'll run plastic conduit over the wiring route so I can pull additional wires as necessary.  This will all be low voltage signals.

Then, out at the back porch, I'll have another box with any solid state relays and other high voltage goodies needed at that end.  I'll set it up so that I can just unplug one 120V power cord to kill all of the HV stuff in the system.  The heater and fan of the modified smoker will simply plug into receptacles on that interface box at that end.

This controller system has a nice, free MMI software and the control software is also free.  So I can then interact with the smoker (or anything on that controller) from any PC connected to our home network.  That will allow for control and data logging, etc. for not only the smoker, but other things around the house.  I'm doing it this way simply because I already have the controller gear and I work with this stuff at my job, so I'm comfortable with it.  It wouldn't be a very practical way of approaching this for most people.

What would be better, cheaper, and more useful for more people would be to set up an Arduino or Raspberry Pi type system to do all of this.  But I'm just not that familiar with all of that, so I'm taking the easy way out for me at this point.  Maybe someday I'll find a lot of time for playing with one of those other, cheaper systems, and then it would be fun to come up with a fancy system that a lot of people could replicate for their own systems.  Heck, if I looked around, I'd probably find that this has already been done a number of times, actually!

But what fun is that?  ;)

I really want to play with it this way because I could use more experience programming the MMI in particular on this system because that will help me at work.  So it's very impractical, but should work for my purposes.  The only things that will likely come of it of any use to most of the rest of us on here is the data I'll gather about what ends up working and what doesn't.

This is a good "prototyping" kind of setup for me because of the extreme ease of programming for both the control system and its MMI (man machine interface).  I can make program changes in a few minutes and be running them immediately.  That's what I need because I NEVER think of everything on the first revision of ANY program. :)

Trial and error and many iterations.  That's what works for me.  :)


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## dr k (Feb 18, 2017)

@Sigmo does the fan controller have a three prong plug so it's grounded? I couldn't tell. If it does I guess it would run mes heating elements being 120v 15A = 1,800W. Just wondering if it would work. If it would then you could turn it on full to preheat and switch to variable without adjusting the dial. As well as bumping the heat up on full for a minute then switching back to variable during a smoke without touching the dial. Keeping my eyes open for when my electronics fail. I may try a rheostat before a PID. I like that switch. 
-Kurt


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## tallbm (Feb 19, 2017)

Sigmo said:


> What would be better, cheaper, and more useful for more people would be to set up an Arduino or Raspberry Pi type system to do all of this.  But I'm just not that familiar with all of that, so I'm taking the easy way out for me at this point.  Maybe someday I'll find a lot of time for playing with one of those other, cheaper systems, and then it would be fun to come up with a fancy system that a lot of people could replicate for their own systems.  Heck, if I looked around, I'd probably find that this has already been done a number of times, actually!


I'm going the the HeaterMeter/LinkMeter route (Raspberry Pi).  It will come loaded with the open source (free and freely available to modify) software pre-loaded.

I plan to do a step by step of setting it up.  Additionally I have no problem writing software to update, enhance, or modify what I can or want with the system.  I don't plan on doing this or doing an extensive amount of software additions but I have a feeling I may add some scripts or two if/when the time comes.  The system seems to be setup for that.

I plan to post a step by step once I do it.  Just gotta wait for the back ordered stuff to come and some time to do it all :)


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## sigmo (Feb 21, 2017)

Dr K said:


> @Sigmo does the fan controller have a three prong plug so it's grounded? I couldn't tell. If it does I guess it would run mes heating elements being 120v 15A = 1,800W. Just wondering if it would work. If it would then you could turn it on full to preheat and switch to variable without adjusting the dial. As well as bumping the heat up on full for a minute then switching back to variable during a smoke without touching the dial. Keeping my eyes open for when my electronics fail. I may try a rheostat before a PID. I like that switch.
> -Kurt


Hi there.

I'm not sure which controller you're referring to.

What I'm going to be using will be based on the Opto 22 SNAP-PAC line of controllers in a SNAP-IT rack that I've got laying around, using various I/O modules as needed.  And the wiring to the smoker's heating element and the fan will be connected to a box that I'll be building.  So in this case, I will install normal 3-Prong receptacles in that interface box when I build it.   I may use 20 Amp receptacles just to allow for the possibility of higher power devices at some point, but all of the receptacles will be grounded, having their ground contacts wired to the main cable that brings power out to that interface box.

The fan I've got does have a spade type "male" for grounding as well as similar spades for the hot and neutral power wiring to the motor windings themselves.  The way I plan to wire the MES is to have two separate three-wire (grounding) power cords coming out of the MES itself.  One will be for the fan, and the other will be for the heating element.  Both of those cables will provide a ground path to the chassis of the MES, so if either one (or both) is plugged in to a grounded receptacle, the chassis of the MES will be grounded.  My "interface box" will be grounded by the ground wire inside of its three-wire power cord, and any and all power receptacles on that box will carry that ground through their ground pins.

In my case, the way I'm envisioning it, since I'll have separate independent control over the fan and heating element, I could do what you're talking about and control the heater power and fan operation separately to get what I want during different parts of a smoke.

I can get SSRs that accept a 4-20mA or analog voltage signal and put out a phase-controlled variable output.  In that case, I could run the fan full blast or at some variable speed under the control of the controller.  But if I do that, and also want to use the fan in the "full-on/full-off" mode, and vary the duty cycle of the "full-on" periods, I would need to create that duty cycle control "by hand" in the program strategy.  But if I forego any variable-speed operation of the fan, I can use the controller's I/O Brain to implement what they call "TPO" (time period output).  When you use the TPO feature on a digital output, all you do is define the total time period somewhere in the program (strategy as they call it) and then tell it what percent "on" you want at any point in the strategy.  That percent on can be the output of one of the PID loops running on that I/O brain.  A bit of overkill, but a really easy, lazy way to get what I want.

I guess you could set things up so that you've got one of the analog-controlled SSRs that act like a "dimmer" based on a 4-20mA or analog voltage signal, and use an analog output module to provide that signal.  Then, you could simply wire that analog signal through the relay output contacts of another digital output module that was configured to be a TPO (time period output).

So you could set the fan's speed with the analog output, and then set the on-off duty cycle with the digital output.  That would let you have any kind of fan operation you might ever want!  The digital output module would need to have a dry-contact relay output for it to properly pass the 4-20mA or analog voltage signal, but I've got a few of their reed-relay output modules laying around that I got surplus a while back.  They come in handy for things like this.  Auber sells SSRs that act like dimmers, and accept an analog voltage input to control them.  You can find them on EBAY, too.

Now that I've written all of that, I'm thinking you may have been asking about that neat speed control that TallBM mentioned earlier.  I need to look it up again, but as I recall, it did have a grounded three-wire power cord, and its output receptacle was also the grounding type.  So you should be able to make sure the fan (and whole chassis of the smoker) is properly grounded.  I do think grounding these smokers is very important.  Anything with a metal cabinet, and used outdoors, or even in a garage, should be grounded for safety.

I can envision setting up the "Recipes" (as the Opto 22 people call what might be otherwise called a "macros") to do a pre-heat sequence.  And for that, as you say, it might be great to have the fan on full blast to get everything up to the desired starting temperature quickly and uniformly.  Then, when the actual cooking begins, you'd likely want to go easier on the stirring fan, depending on what you were cooking.

I'd be controlling the temperature via a PID loop the whole time, but depending on how that PID loop is tuned, it'd have the heater turned on pretty much full blast while preheating anyhow.  That's the nice thing about a PID loop.  It'll heat up to the setpoint as fast as possible, but shouldn't overshoot or "ring" much if any at all (if tuned correctly).  But tuning a PID loop can take a bit of tweaking.  Most PID Controllers that you buy as a separate gadget have an "auto-tune" mode, which, if done correctly, can get the tuning pretty darned good on one try.

I don't think I'd ever bother with a variable power "dimmer" kind of thing for the heater if I had a PID controller to use instead.  If you set the PID controller (or software) to a fast enough cycle time, the heating element will be turned on and off fast enough that for all purposes, you wouldn't be able to tell the difference between that and a dimmer (as far as smoothness of the control).  Most of these heating elements are fairly heavy and don't heat up or cool down all that fast.  So using a fairly short time period for the PID loop would make for very smooth heat control with very little cycling up and down of the temperature in the smoker.

The thing to remember about one of these speed control (dimmer) type units is that they're great for setting a fan speed or something like that, but for setting the temperature in a smoker, they'd be kind of a hassle because they're not really a temperature controller.  They don't know what the temperature in the smoker is.  So you'd have to "be the controller", adjusting the knob while watching a thermometer all of the time.  You really would want a thermostat or PID controller of some sort to make the system easy to use and forgiving of changes in sun, outdoor temperature, wind, rain, and the wetness and temperature of the meat you were cooking, too.  One of the things I love about the MES just as it came from the factory is the ability to just set the temperature and then not worry about it.

It really has spoiled me versus tending my charcoal smoker!


TallBM said:


> I'm going the the HeaterMeter/LinkMeter route (Raspberry Pi).  It will come loaded with the open source (free and freely available to modify) software pre-loaded.
> 
> I plan to do a step by step of setting it up.  Additionally I have no problem writing software to update, enhance, or modify what I can or want with the system.  I don't plan on doing this or doing an extensive amount of software additions but I have a feeling I may add some scripts or two if/when the time comes.  The system seems to be setup for that.
> 
> I plan to post a step by step once I do it.  Just gotta wait for the back ordered stuff to come and some time to do it all :)


Hey!  That looks like a nice way to go.  Lots of possibilities with all of that, and I like the remote radio link part of it, too.  That's more like what I was thinking would be a nice, practical way of implementing this!  So I'll be interested to see how this works out for you.  Plus, I should read up on that equipment.  I need to play with the Raspberry Pi system and become familiar with it and the Arduino stuff.  I have an Arduino experimenter's kit that I have yet to play with at all!  Just too many projects, always, I guess.  But I WILL eventually play with it.  There are so many possibilities with Arduino and Raspberry Pi that it's a shame not to become intimately familiar with it all.  So many projects come to mind, don't they?  :)

It looks like the page I landed on when I searched is aimed at controlling a fan or damper to control temperature in a charcoal burning system.  I thought about that quite a bit before I got the MES.  I still think that all has a lot of potential, too!  There were some aspects of my ECB smoker that really were kind of nice.  But the electric smoker has spoiled me and made me lazy, I guess, so I've gotten side-tracked into that for now.

It seems like modifying the program to run an electric heating element would be fairly straightforward, and if I took the time to read further, I'd probably find that this has already been done!

I'll post a step by step thread showing what I end up doing, too.  It won't be as useful as yours because of the rather obscure hardware I'll be using, but the measurements and observations about how things work inside of the smoker will hopefully be useful to everyone.

This will be fun, and especially so with several people going at it from slightly different directions and sharing their observations and hints!


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## dr k (Feb 21, 2017)

Dr K said:


> @Sigmo does the fan controller have a three prong plug so it's grounded? I couldn't tell. If it does I guess it would run mes heating elements being 120v 15A = 1,800W. Just wondering if it would work. If it would then you could turn it on full to preheat and switch to variable without adjusting the dial. As well as bumping the heat up on full for a minute then switching back to variable during a smoke without touching the dial. Keeping my eyes open for when my electronics fail. I may try a rheostat before a PID. I like that switch.
> -Kurt


-Kurt


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## tallbm (Feb 21, 2017)

Dr K said:


> -Kurt


Kurt, I believe it does have the 3 prong plug (99% sure).  I looked at it this weekend when it came in the mail but I won't be able to confirm 100% until I get back to it this weekend.

I believe you could do what you desire with this controller to make your smoker into an analogue style one.  I thought I read about someone doing that here with their MES while still using the stock MES electronics for the temp sensing and such.  They just simply rewired so the controller was no longer connected to the heating element and used the dial to control power to the heating element.  They used the onboard MES electronics and thermometer to read temp and then they would manually adjust the power to the element with the dial.

I'm pretty sure it is a 3 prong all the way through because I have it on my todo list to figure out how I'm going to ground fan motor when I build a chord for it.  My guess is I could simply just run the ground through the MES backing down to the same location the MES using for a ground.  I have a strong feeling I will put the fan in the back of the MES to stir the air inside.  I'm going for a keep it simple keep it stupid approach for the fan portion of the modification.  Putting it in the back and piggybacking off any existing wiring strategy, etc. is a simple way to go and I think any stirring will be a noticeable improvement even if it is not the most ideal stirring setup.

I also need to figure out how I'm going to drill the hole and insert the fan shaft through the body of the MES.  I want to keep smoker/air from going into the body and insulation of the smoker. 

I think I am going to buy a stainless steel pen, remove the guts, then cut it to the proper length to use it as as fan shaft guide tube.  I would then drill holes to accommodate the pen body shaft guide tube and"fasten" it to the back of the inside of the MES inner chamber while having it stick just outside the back of the MES so I can pull the back off at will with no issue from this tube.  See my ugly attempt at what this would look like below lol

Cheap stainless steel pen like this or something similar.













BLK-Sharpie-Pen-SS-2.jpg



__ tallbm
__ Feb 21, 2017






My ugly sketch as an idea not as an exact schematic, I don't know where actual fan placement will be yet:













penShaftGuideTube.png



__ tallbm
__ Feb 21, 2017


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## dr k (Feb 21, 2017)

@TallBM
Thanks for the controller input.  Like I said I like the switch from full to variable. This is for down the road when contrllers fail. I though about a fan like you  and Sigmo are doing to mix air evenly in the smoker awhile back but it was just a thought. I thought about putting the fan in the bottom corner at the door on the hinge side of the gen 1facing the latch side so a current would start out going across the bottom face of the door, and rise with the air coming in from the mailbox mod, going the same direction. 

The pen grommet sounds like a good idea to keep insulation where it's supposed to be. And the pen tapers so that maybe good to use if possible. I don't know. 
-Kurt


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## sigmo (Feb 27, 2017)

Hi, Guys!

I think the controller you're looking at, Dr K, will work as TallBM described.

The only real drawback I see with it is that you will no longer have a thermostat.  Instead, you'll just be adjusting the power to the heating element directly yourself with the knob.  So you'll have to constantly monitor the temperature in the smoker and adjust the power to the heating element yourself.

I've gotten spoiled by the MES, and I like to be able to set the temperature of the smoker, then walk away from it and have a thermostat maintain the temperature I've set.  So that's one of the main things I really like about these electric smokers versus (in my case) the charcoal unit I have.  However, if you'll be tending the smoker during the run anyhow, then the control you'll looking at would likely work just fine.  It won't be any different than running a charcoal or gas smoker in that regard, and really, the charcoal unit of mine has worked just fine.

You'll probably get a good feel for what settings of the knob work the best for different meats and weather conditions just like we do when running a charcoal unit.  But it will be a lot easier for you to adjust the power than it is with a charcoal smoker.

I'd do like TallBM suggested and use a three-wire power cord.  Use the hot and neutral to power the heating element, but wire it so that the snap-disk thermal cut-off device is still in that circuit.  Then connect a good ground from the chassis of the smoker to the grounding wire of that three wire cord.  Then the ground pin of the controller will carry that ground through to the ground of the receptacle into which the controller is plugged.  That way, the controller and the smoker will both be grounded.

TallBM:

I like the idea of a sleeve between the inside of the smoker and the outer wall to seal things off from the insulation space.  It would be good to keep moisture and smoke out of that space, I think!

Maybe a guy could use some high temperature RTV to seal both sides (or at least the inside end) of the sleeve tube.  But the tapered pen casing might work great just by itself because you could push it into the hole from the inside until it jams in place and makes a seal to the inside wall of the smoker.  I'm going to want to do the same thing for mine.  I don't like the idea of condensation forming in the insulation space.  I want a "vapor barrier" like you'd install in the walls of a house or building, I guess!  :)

I found out Opto 22 has an app for Android or IOS devices to let you access various things over a WiFi network to which the controllers and I/O are connected.  I just played with it, and it works great, but I'll have to use one of their newer Snap PAC controllers to have access to the "Strategy Tags".  The older model controller I tried this with lets me look at I/O, and control it as well, but it would be more convenient to be able to adjust variables, tables, etc., in the running strategy, and the older controllers don't know how to do that.  I've got newer controllers laying around, so I'll use one of those and try that out when I get the chance.

I was thinking I'd need to use a laptop or other PC connected to the network to adjust and monitor things, but this little app, running on a tablet or phone will do everything I'd really need, too, so that'll be cool.

They've got a full-blown system for remote access to their systems that lets you create very user-friendly Man Machine Interfaces to run on phones or tablets, and connect from anywhere that you have internet access, but they actually want real money for that setup!

Being a cheapskate, I want to do this all with bits and pieces I already have laying around and with their free software.  This app was just $5, so that's acceptable, I guess.

Woo Hoo!  I can see the temperature in my office now from anywhere my WiFi reaches, and I can turn a light on and off as well as adjust the duty cycles of some Time Period Outputs.  Yee Haw!  (It doesn't take much to amuse a nerd, I guess)   ;)

When I get the new style controller set up and configured, I will be able to adjust variables within a running strategy from my phone or tablet, which will let me adjust setpoints and such.  There are ways to let this work over the internet, too, but I'm not sure that's really necessary since I'd at least be somewhere around the house while smoking stuff.  Just being able to monitor and control things from an easy chair or the like without needing to go out in the cold is nice.  That's one of the features I've always liked about the MES (and similar smokers).  So it will be nice not to lose that feature.

And that looks like one of the nice features of the system you're using, too.  Remote control and monitoring is nice.  I'm thoroughly spoiled.


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## tallbm (Feb 27, 2017)

Wow Sigmo, it looks like you are well on your way to an awesome controller setup with the apps and all.

You might want to check and see if you can still connect with your app when you are out of your personal wifi network range.

I know network enabled security cameras do this with their apps so you can view live feeds, few recorded pics and videos, turn on/of alerts, etc.  I don't see why your app would not work the same way once setup, but I guess this is something you will want to confirm while at work or at the grocery store some day.

I think I have all of my pieces in.  For the sleeve I was thinking I would high temp silicone it to the the inner chamber and use some 600F flue tape to assist and then let the tapered end sit outside the back end and allow the taper to provide a metal to metal "seal" that I would then reinforce with the 600F flue tape.  Or vise-versa...something along those lines.  I'll know more when I get down and dirty with the parts and the MES.

The Heater Meter already comes with an app (free I believe) and I believe I can access the controller from my phone as long as it is on and connected to my wifi network.  So I can kick the smoker on from the grocery store to start warming up when I find a nice piece of marked down meat :D

Also I have wired in a 350F manual reset into my Gen 2 guinea pig MES I have setup for my mother.  This way a 325F temp can be set ONLY for chicken/turkey with skin.  All other smokes will be no higher than 275F.   I will get acceptable chicken skin form an MES dammit!!! :)

I'm about to play with all of my HeaterMeter/LinkMeter parts this evening so I can figure out the final piece I am waiting to buy.  The final piece is the project box/enclosure once I know how much room things will take up.

I'm like you, very excited and happy to see things coming together!


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## tallbm (Jun 13, 2017)

Well I figured I would kind of put the concluding post on this thread.

I decided to rewire the MES and go with a PID controller for it.  I went unconventional and used the HeaterMeter controller and I feel I have completely eliminated the Temp Swings!

I also installed a convection fan to try and even out the temps throughout the smoker.  The fan has improved things quite a bit BUT it seems that there is just NO way to get the entire smoker to be consistently even.  Between racks there will be differences in temp and even along a rack there will be differences.  The fan has at least helped the differences become much more consistent.  For example if the bottom rack is right on then the top rack may be off by 25 degrees but across the rack it is close to a 25 degree difference and seems to hold true to that difference.  I was not able to make the top and bottom racks the same but I think this is about the best that can be done with the device.  It is a smoker not a convection oven and vents smoke plus air right out of the top so it is more difficult to retain temp at the top most racks that would be the same as the temp at the bottom most racks.

In any case I bypassed the stock MES controller and probes and I have improved upon my smokers biggest issues.  Soon I hope to post about all of my mods but as for now here is the thread with my mods being discussed as I was working through them.  

I wish everyone the best with their MES temp issues and I hope you enjoy my little journey and the info I've shared.  Thanks! :)

http://www.smokingmeatforums.com/t/261790/mes-mod-madness-teaser-pics

Pic of steady temps using my HeaterMeater PID controller, look at the orange and light green line at the top of the pic holding steady  :)













ptunes.png



__ tallbm
__ Jun 12, 2017


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## downeast smoker (Jul 4, 2017)

Bear,  I am doing my second smoke with my MES30 (brisket this time) and now that I have a good digital thermometer (ThermPro TP-20) I see that when my MES temp guage says 240, the actual temp (with probe hanging just above the meat) is only about 220.  So I am doing what you suggested here and raising the setting on the MES to get the desired temp based on what my ThermPro is telling me.  I will be contacting Masterbilt about this and see what they say or will do about it.  I will do the boil test which I just read about later, but when I took the ThermPro out of the box, installed the batteries and turned it on, the temp reading was 73 degrees, which was exactly the anbient temp in the room I was in, so I am quite sure the ThermPro is accurate.  I think the fact that I was cooking the Boston Butt at a temp 20 or 25 degrees lower than I thought it was at is a reason I was having a problem getting smoke.


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## Bearcarver (Jul 4, 2017)

Downeast Smoker said:


> Bear,  I am doing my second smoke with my MES30 (brisket this time) and now that I have a good digital thermometer (ThermPro TP-20) I see that when my MES temp guage says 240, the actual temp (with probe hanging just above the meat) is only about 220.  So I am doing what you suggested here and raising the setting on the MES to get the desired temp based on what my ThermPro is telling me.  I will be contacting Masterbilt about this and see what they say or will do about it.  I will do the boil test which I just read about later, but when I took the ThermPro out of the box, installed the batteries and turned it on, the temp reading was 73 degrees, which was exactly the anbient temp in the room I was in, so I am quite sure the ThermPro is accurate.  I think the fact that I was cooking the Boston Butt at a temp 20 or 25 degrees lower than I thought it was at is a reason I was having a problem getting smoke.


Sounds better than before.

However if it continues to be more than 15° lower (actual temp) than the MES says, I would contact them too, because if you have to set your MES to 240° to get 220°, or set 260° to get 240°, that means if you set it to the MAX--275° the highest you can get is 255° at best.

You paid for a Smoker that could get to 275° and stay there as long as you want it to.

I think their guarantee is +/- 15°.

Note: Being 20 or 25 degrees lower than you thought shouldn't affect the smoke. If there are no other problems you should get the same smoke at 220° as you get at 260°.

Bear


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## PaddlepopLion307 (Jan 11, 2019)

This thread was incredibly helpful and I have now fooled the sensor.

I folded a few layers of foil and folded a flap 2" from the end. I put a rack on the bottom rail just above the factory water tray and put the foil on top of the rack with the flap pressed against the wall under the rack.  
This formed a sort of scoop which directs hot air away from the back wall where the sensor is and towards the door.

Ontop of this I put my water tray further sheilds the sensor and now im able to get the general unit temperature up past the maximum of 275.  I have reached up to over 300 so now i can cook my briskets in less than 8 hours!

I might make up a custom rack to snuggly fit the shape of the wall. Will post pics when I do.  I have an idea for air circulation without installing an active fan by using the custom rack to evenly distribute the air flow.


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## tallbm (Jan 11, 2019)

PaddlepopLion307 said:


> This thread was incredibly helpful and I have now fooled the sensor.
> 
> I folded a few layers of foil and folded a flap 2" from the end. I put a rack on the bottom rail just above the factory water tray and put the foil on top of the rack with the flap pressed against the wall under the rack.
> This formed a sort of scoop which directs hot air away from the back wall where the sensor is and towards the door.
> ...



Hi there and welcome!
That is some cool info to know.

Just a word of caution though.  The MES has foam insulation that will have a certain max operating temperature limit.  No one I know of seems to know what that limit is and if I remember correctly, every can of foam insulation I googled in the past didnt have a listed limit or one over 300F.  The industrial stuff can go higher but that isn't something the average Joe would be handling.  My *GUESS* is that the existing MES foam insulation probably has a continuous temp rating in the 330-350F range.
If you push your smoker too hot for too long your insulation may burn up, gas out, and or catch fire.

I can make my smoker go to 325F but I only do it for my *fast* poultry smokes to get edible skin rather than leathery skin.  Other than that I don't go over 275F since that was the top temp the MES was "supposed" to hit.  Be cautions of 4+ hour smokes and getting too hot.

I hope this info helps and best of luck with the smoking and temp control on the MES.  We all fight that battle to some extent with the MES :)


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## PaddlepopLion307 (Jan 12, 2019)

tallbm said:


> Hi there and welcome!
> That is some cool info to know.
> 
> Just a word of caution though.  The MES has foam insulation that will have a certain max operating temperature limit.  No one I know of seems to know what that limit is and if I remember correctly, every can of foam insulation I googled in the past didnt have a listed limit or one over 300F.  The industrial stuff can go higher but that isn't something the average Joe would be handling.  My *GUESS* is that the existing MES foam insulation probably has a continuous temp rating in the 330-350F range.
> ...




Yea thanks, I saw the post about the crackling noise someone noticed at 340f so its on my radar.
Ill report back if I run into any trouble!


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## dr k (Jan 12, 2019)

A guy on FB drilled a hole just big enough in a cork to slide over the Mes sensor to get higher temps since his Mes maxed at 250 so now he gets 275 at second from top rack.  I'm not sure if the cork has been cut to the length of the sensor, drilled all the way through and/or butts against the back wall.  Enough heat from the back wall feeds the sensor. If I still used the Mes controller I'd give it a shot and run some tests since my Mes never got to 275.


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## Bearcarver (Jan 12, 2019)

PaddlepopLion307 said:


> Yea thanks, I saw the post about the crackling noise someone noticed at 340f so its on my radar.
> Ill report back if I run into any trouble!




Yup---That was me with the "Crackling" insulation.
I would seriously avoid going over 330°, and wouldn't hold over 275° for any extended lengths of time.

Bear


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## BrianGSDTexoma (Mar 26, 2019)

PaddlepopLion307 said:


> This thread was incredibly helpful and I have now fooled the sensor.
> 
> I folded a few layers of foil and folded a flap 2" from the end. I put a rack on the bottom rail just above the factory water tray and put the foil on top of the rack with the flap pressed against the wall under the rack.
> This formed a sort of scoop which directs hot air away from the back wall where the sensor is and towards the door.
> ...



Do you have a picture of this?


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## BrianGSDTexoma (Mar 26, 2019)

PaddlepopLion307 said:


> This thread was incredibly helpful and I have now fooled the sensor.
> 
> I folded a few layers of foil and folded a flap 2" from the end. I put a rack on the bottom rail just above the factory water tray and put the foil on top of the rack with the flap pressed against the wall under the rack.
> This formed a sort of scoop which directs hot air away from the back wall where the sensor is and towards the door.
> ...



I giving this a shot.  Does look like what you did?  Water pan pretty close to probe.


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## BrianGSDTexoma (Mar 26, 2019)

I was able to get smoker to run 240 to 250 set at 275 configured like this which is where I want to be if it will stay like that.


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## sigmo (May 1, 2019)

tallbm said:


> Well I figured I would kind of put the concluding post on this thread.
> 
> I decided to rewire the MES and go with a PID controller for it.  I went unconventional and used the HeaterMeter controller and I feel I have completely eliminated the Temp Swings!
> 
> ...



Hey, it's only been a couple of years since I added anything to this thread!  :)

I've been busy, and may still not get this all set up too soon, but:

Having set up a security camera system here, I've been through a lot of learning and work with that.  And part of that lead me down the path of setting up my own VPN running on my router.  The idea is to NEVER let any of these cheap security cameras communicate directly with the internet because most have back doors, and all of them are pretty easy to hack, so they're big targets for hackers.  Once you give a camera access to your network, and also allow it to have access to the internet, you've set up a "man on the inside" that can spy on all of your network traffic and send whatever it wants to its masters (usually in China).

Anyhow, the upshot of having my own VPN running on my system is that my wife and I can open a secure tunnel to our home network from anywhere, and once that's "switched on", we can access our home network as if we were right there logged into that network.  That opens up a lot of possibilities, and it also allows us to surf or shop online even if we're on a public network because all of our traffic is encrypted with 2048bit encryption both ways.

This is NOT the same as using a VPN service.  It's our own VPN, running on our router.  (There are other ways to do it, as well, but this was easy).

VPN services are also very handy, but for accessing gadgets on our home network remotely, having our own VPN is the way to achieve that goal securely, with no port forwarding, or other serious security issues.


I still need to modify the MES, but I'm also looking at getting a larger smoker as the starting point for these modifications.  Someday I may actually get around to doing some of this!  :)


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## tallbm (May 1, 2019)

sigmo said:


> Hey, it's only been a couple of years since I added anything to this thread!  :)
> 
> I've been busy, and may still not get this all set up too soon, but:
> 
> ...



I completely understand where you are going with it.  I just chose to not open my HeaterMeter up to the internet hahaha.  Also I got over the idea real quick that I would be away from my smoker or working it remotely while NOT at home.  It is a very cool idea but not practical if you don't have someone within 10 seconds of the smoker should there be a flame up situation or anything else that could be dangerous or at least ruin the meat.

In any case a VPN is awesome to have regardless of using it to control and monitor a smoker :)


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## sigmo (May 2, 2019)

Yep.  It's probably not a really good idea to leave this kind of thing unattended! I guess you could watch your porch going up in flames via the security cameras. At least for a while!  ;)

I will say, though, that I frequently smoke pork butts overnight, and sleep while smoking.  It's nice to be able to just roll over in bed and check things, but even that is potentially risky, for sure!

The security cam footage of a guy in pajamas desperately extinguishing what's left of his smoker would be pretty amusing on the evening news, though!


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## tallbm (May 2, 2019)

sigmo said:


> Yep.  It's probably not a really good idea to leave this kind of thing unattended! I guess you could watch your porch going up in flames via the security cameras. At least for a while!  ;)
> 
> I will say, though, that I frequently smoke pork butts overnight, and sleep while smoking.  It's nice to be able to just roll over in bed and check things, but even that is potentially risky, for sure!
> 
> The security cam footage of a guy in pajamas desperately extinguishing what's left of his smoker would be pretty amusing on the evening news, though!



Hahhahahaa yeah I agree!
I too smoke overnight on briskets and pork butts but I have high temp and low temp alarms set.  I've been woken up one time where strong winds picked up and caused my pellets to ignite, raise the temp, and set off my high temp alarm.
I run a mailbox mod so it is all contained well on the side but man those alarms sure do help and yeah being away while that happened could have lead to something serious rather than 2 rows of burnt pellets!


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## sigmo (May 3, 2019)

Yes.  Setting alarms is a really good idea.  Not only for safety, but also to keep from spoiling a good smoke!  Catching a problem quickly can make a flare up, or other problem inconsequential.

It also makes sense to arrange the various parts of our smokers so that the chance of having a fire spread to anything else is minimized.  Even though the smoker is electric, and may be reasonably safe by itself, I do run either a mailbox setup or an AMNPS directly in my smoker, and use pellets, so I'm playing with fire there!

We all have to consider worst case situations as we set up our systems, and try to do things as safely as possible.  The remote controls on these smokers encourage us to run them without direct supervision, but that does create more danger, so we have to be especially careful.


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## Bearcarver (May 3, 2019)

FYI:  I know of an MES that somehow got Fat drippings inside the door, and it lit up & went to flames. He was there & put the fire out without any other fire problems.
Masterbuilt gave him a new door, No argument, probably wanting to keep it Hush-Hush.

Bear


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## tallbm (May 3, 2019)

Bearcarver said:


> FYI:  I know of an MES that somehow got Fat drippings inside the door, and it lit up & went to flames. He was there & put the fire out without any other fire problems.
> Masterbuilt gave him a new door, No argument, probably wanting to keep it Hush-Hush.
> 
> Bear



This brings up a good point that I have been debating.
What is a better/best and reliable home or mini fire extinguishing unit to have on hand? 
I have researched this a little and disappointed that the "recommended" (mainly Kidde) had so many issues, failures, and just lack of reliability.  I am relying on my backyard water hose right now but would prefer something faster and located very near my smoker.

Anyone have any foolproof suggestions?
Any fireman or fire related professionals have any input?


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## Jonok (May 3, 2019)

A CO2 extinguisher would probably work just fine especially as you could use it without attempting to open the door (via the vent or the chip loader) the other advantages are that they don’t make a giant mess with powder or other media, and they only cost a few bucks to refill.

That being said, the “right” answer for cooking grease fires is a type K extinguiser which uses an alkaline medium (at a low enough pressure to essentially turn the burning grease into soap, and thus smother the fire without spraying burning grease everywhere).  They work well, if  you can get them on the fire (think fixed extinguisher heads over a commercial cooktop or deep fryer), but the various alkaline agents are corrosive and make a mess out of shiny metal.

In any event, the best way to put out the fire is by removing the ignition source (unplug the smoker) and smother the fire (cover the air inlet and vent). I would strongly advise against opening the door, or spraying water on it.  Needless to say, this is why the literature for your smoker says not to put it on, adjacent to, or under a flammable  surface.
(I’m a Burn doctor who sees a lot of people who try to carry burning pans of grease out of their house)


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## dr k (May 3, 2019)

If *you* have a Class B dry chemical *fire*extinguisher, *you can use* it as well. *You can*also *put out a grease fire* with baking soda or salt. Keep in mind that it takes a lot, so it only works for small *fires*. But make sure *you* don't grab anything else by mistake—baking powder and *flour will* both make the *fire* even worse.


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## Bearcarver (May 3, 2019)

tallbm said:


> This brings up a good point that I have been debating.
> What is a better/best and reliable home or mini fire extinguishing unit to have on hand?
> I have researched this a little and disappointed that the "recommended" (mainly Kidde) had so many issues, failures, and just lack of reliability.  I am relying on my backyard water hose right now but would prefer something faster and located very near my smoker.
> 
> ...




I just got rid of a bunch of bigger ones that were real old (from my old Cabinet shop).
Then I got 3 brand new 5 pounders that are A-B-C. Should handle anything I need them for.
I'm gonna hang one just inside the front door, for use inside or on my Smoking & Grilling Porch.
Another one just outside my Kitchen door to the garage, to handle the garage & kitchen.
The Third one will go in the basement near the Heating Room.
All 3 were only $84.

Bear


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## sigmo (May 3, 2019)

OK.  Now I've got another thing to add to my control system:

A fire suppression system!  ;)

My wife got a Halon extinguisher as a safety award from the hospital where she worked.  We keep that one in the kitchen for grease or other fires there.  The advantage of Halon is that you won't be reluctant to use it because it won't create an extra mess.

But as Bear points out:  A good ABC extinguisher is a good thing to have anywhere.  They're usually dry chemical, so they will make a big mess, but often the alternative is much worse!  I like to have one near every exit because when you get to the extinguisher, you can look back at the fire and make the executive decision between returning to fight the fire and simply running out the door for your life! 

Having one handy near your smoker would certainly be a good idea.

The garden hose might be good for putting out your porch or the side of your house, but unless you've disconnected your smoker from the electrical outlet first, spraying it or the area near it with water could be quite dangerous.  Most water has enough mineral content to be quite conductive, and it will run into small openings.

Of course, this is one more reason to have your smoker plugged into a GFCI protected outlet.

Where I used to work, we did annual fire training, and everyone got to try their hand at extinguishing a burning liquid fire usually consisting of diesel fuel started with a bit of gasoline by the folks giving the training.  I think it's great to have everyone get to actually use a fire extinguisher every so often so it's second nature and you don't have to read the instructions on the extinguisher as you're watching the fire get bigger!

It also gives you an idea of how much (or little) a given size of extinguisher contains, so you won't waste precious retardant, and will get what there is on target for best results.

Muscle memory is a good thing in an emergency.

PASS

Pull pin, Aim (at the base of the flames), Squeeze the trigger, and Sweep side to side to cover the burning material.


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## Jonok (May 3, 2019)

Not to belabor the point,
(but I'm gonna, because I'd rather teach people how not to get burned than to do their skin grafting)

ABC will work for Class A (normally burning solids, like wood, paper, etc. B is for burning liquids that are not self oxidizing, and C is for general electrical fires (based on the conductivity and corrosivity of the extinguishing agent).

Most ABC extinguishers are charged with Mono ammonium phosphate (because it's not very conductive), but some are just charged with baking soda.

Either charge will work to suppress common fires, but MAP is easier on electronics and harder to clean up.

Common "Consumer" (non-recharge,<10#)ABC extinguishers are essentially "One and Done" in that, once you activate the trigger, a lot of stuff is coming out in a hurry, and you can't effectively control volume or velocity.  so if you're in a situation wherein there's a bunch of flaming grease in a puddle, you stand a good chance of spraying it all over the place.  Unfortunately, Halon, which is really good at not poisoning, (though still good at suffocating, in fire-suppressive concentrations), you or your passengers (on a Boat or Airplane) or trashing your sensitive computer equipment, is a long way from optimal.  Halon delivery systems are designed to flood areas with high pressure/high volume streams of non-fire supporting gas, and are, therefore, nowhere near as "Modulatable" in terms of putting out a mundane liquid fire with a minimum of rigamarole as is CO2, and this is because CO2 extinguishers are made with "variable speed" valves. (think PUFF (wait) PUFF (wait) PUFF...
They have that great big cone on the front so that they don't freeze, and also so, in order that they don't blow burning liquid all over everything you are trying to save, you can keep the velocity of the gas flow low, but still very turbulent and high-volume.  (they also produce exponentially more extinguishing gas volume for a given weight than do other extinguishers.
Give Halon's exponentially higher costs and reduced utility for a potentially "mundane" fire environment, I would strongly recommend a 10# CO2 system for a fire-prone situation such as you describe, and just to make sure, go set some stuff on fire in the back yard, and put it out (for the $15 recharge fee) and you'll be much better prepared than before.


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## tallbm (May 6, 2019)

Wow guys thanks for all the info!

My main concern is to keep the house from burning down. My smoker isn't too close but I have it in a little plastic shed, which again is not too close BUT if the shed starts to go up then the fire is bigger and floating materials (not sure there area any) could blow to the house or the fence, etc.

My most likely fire situation would be from my mailbox mod which is self contained and I can remove it while wearing an oven mitt (have done this).  Secondary would be if that flame were go get into the MES enough and light up some grease.
In that case the MES is self contained and I would just shut the vent and unplug the MES and let it kill the flame.

Outside that we are talking about the MES burning down which ignites the shed which may be able to burn against the house which is brick in those areas but floating flaming debris would be something I don't want to get into.

Again, I'm extrapolating out all the possibilities and I just want to be able to stop it at the most likely sources.
Even though my MES is in a shed I don't have it too close to any walls and I am confident I can keep a grease fire contained inside of it should one happen.

I think a good C02 extinguisher and the water house should have me covered (and unplugging the MES first thing).

This is been super informative guys, thanks!!!!!


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