# Gravity feed smoke box???



## hotburn76

Hope this is not is the wrong spot but not sure where to put it.  I am new to the forum and new to smoking.  I have a chargriller but do a lot of fab work and would enjoy someday building my own smoker.  After doing lots of looking I have seen a few gravity feed heat/smoke boxes.  How do these work, the mechanics of it?  From the pics I have seen its a long tube full of wood and charcoal.  the top is sealed and controlled air in the bottom.  Heat and smoke exit the side into the smoker, ash falls out the bottom and the fuel falls down as the coal is burned?  And the fuel stack does not but due to the lack of air in the chamber?  I like this concept, but not sure if I understand it or I am way off base.  Was unable to find a post describing the function of it.  Is this a good way to do it or bad?  Thanks Guys.

Jason


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## carpetride

You got the basics right. Your fire is at the bottom of the tube with an ash box below. You have a smaller tube that lets the heat flow across to the smoke chamber. Typically this tube is a couple inches up the charcoal chute. However high your crosstube is, is how high your fire will build to...if you have an airtight chute.


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## hotburn76

So if the chute is say two inches from the grate I would have a coal pile the size of the chute opening plus the two inches.  And if five inches above it would be a bigger coal pile and more heat?  Also when you open to check your fuel supply does it all flash and catch on fire since you just gave it air, or do you have to leave it open for a while in order for that to happen?


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## carpetride

I'm going to upload a sketch that I have, give me a few moments

Ok I didn't draw this, I picked it up when I was looking around for ideas on building one.








You will more or less have fire from the grate to the top of the cross over, maybe slightly above.


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## carpetride

My chute is over 4' tall and I generally just fill before I start and have never had a need to check my level until the next smoke.  I haven't had a flash but have talked to some guys that have...would think this would only happen if you had very little charcoal in the chute.


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## hotburn76

Thanks!  Sorry but one last question.  Can these be used on uninsulated drum style smokers or do they only work on well insulated fridge style?  Thanks for your help and quick replies!!

Jason


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## carpetride

The concept should work, on most anything as it is nothing more than a delivery system. Just understand that while it is an efficient system, the true efficiency comes from the insulation. You have two different items going on...fuel delivery and retention of heat.

The original idea originated in Africa as way to cook with very little fuel (maybe a single lump). Not quite the same design though...been a long time since I read that so I maybe paraphrasing a bit.


Edit:  I'm gonna suggest to a MOD that this get moved to the builders section so that a few others chime in with more practical experience than myself.


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## zapper

Do a search for "Stumps Smokers" or Stumps clones

Ther is a guy here in GA., "Stumps", that makes a line of smokers based on the self feeding and super insulated cooking chamber concepts.

I have read alot about them at other forums and "Stumps" has even chimed in to answer questions and express his gratitute to those that post their designs and research. While am sure that he would rather folks just bought one of his units, he seems to take a homemade clones as a form of a compliment. 

I live close enough to drop in for a visit with him but havent found time. (reads as fear of dropping money on a new smoker
	

	
	
		
		



		
		
	


	





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I have my eye on a 6 x 12 chunk of tube steel at work that keeps taunting me to make it into a feed chute. I would fillet it and reweld it together to make it tappered. Tappering the chute is supposed to help stop clogs or "bridging" of the fuel. For the burning/cumbustion chamber, a thicker metal is reccomended to help prevent burn thru, I read about this fairly often. Controling the air intake for combustion is usually done with a simple plumbing valve or upgraded to electronically controlled fans like Stoker or Guru or whatever other brands are out there or their homemade counter parts

I seem to recall a post on this site about a build, I may see if I can find it. (my search skills stink though)


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## meat hunter

DaveNH sent me this a while back. TONS of info and pics. A great resource for gravity style smokers like the Stumps.


http://www.phpbbserver.com/smokinjim...orum=smokinjim


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## zapper

Yep, Meathunter has the site I was thinking of. (I couldnt recall my password)


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## crd26a

It would work on any smoker type, but you have to have the top sealed (to prevent the fire from climbing) and you'll want VERY thick steel (read 3/8 to 1/2 inch) wherever the fire is at or you'll burn through the steel over a period of time.  

There's three basic manufacturers of the verticals, Stumps, Superior, and DW Kountry Cookers.  There's history between the three, I know a good part of it, but doubt I know all.  They all operate in a similar fashion and have similar characteristics, but there are some differences.  My competition teammate and I just picked up two of the Superior SS-2's after looking at the others (felt these were right for us vs. the other two) for specific reasons I'd be happy to share in a PM.

Also, there's a great community of clone builders on the Prairie BBQ Association forum if you'd want to go that route and build your own.  I thought about it (with some help of another comp team) but by the time I put time, money and basic materials together, it would have been about the same price for the unit I ended up with (but the build would have been bigger).  I'm happy so far with it.


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## carpetride

I had not heard of the Kountry Cooker, just looking at the outside you could mistake it for my Stumps. If I hadn't came across the deal that I did on my stumps I would have built a clone (maybe with some help).

The drawing posted above originally came from the site previously mentioned. I've got a file of ideas that I gathered up if anybody gets serious about building a clone. I thought the ones with the heat entering bottom center were most interesting.


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## zapper

crd26a

Ill take you up on that PM if you feel posting your opinions or reasons for buying what you did is improper. 

I have read just about all of the clone builders post at a couple of sites and feel like an armchair professional on the topic but no real hands on expeirence
	

	
	
		
		



		
		
	


	





Any ideas of what would be a better design in construction, function, price or even looks  are welcome

I could build just about any size or style pit/smoker out of just about any material that I wanted, but I always have the fear that I would miss something of not like it and have to start over from the get go. Thus, my quest for the smoker continues.....


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## crd26a

Nothing improper in our reasons - we liked having the firebox on the back versus the side, allowing for the door to open all the way versus stopping.  For the size of unit we were looking at, Stumps vs. Superior, Superior has 5-6" gaps between racks while Stumps averages around 3".  (The new Stretch has 7" but is a bigger footprint).  This is fine for Ribs, hard to get foiled butts/briskets on w/o taking out a rack.  We also liked that Superior's chute is tapered - starts around 6" diameter and moves to 9" diameter by the time it hits the bottom, plus I like the removeable grease deflector in the bottom.  D.W. gave us a pretty good offer for some other reasons, but finally, with price, size, and features, we felt the Superior was the right size for us.  I have no doubt in my mind that Stumps and DW make great cookers, Superior just worked the best for us.


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## coz

I am in the start of gathering material to start build # 4. #1 was a vertical which died an unfortunate death when I didnt get the chute emptied and went down the road and it started back up.# 2 which may be one of the mentioned ones where the heat enters the cook chamber from the bottom center was never completed as its to amall for our needs .#3 is a clone of Stump Platinum model which is a reverse flow offset type just a gravity feed instead of a stick burner.#4 will be a different version of #3 But it will be reverse flow GF.I think if you have the resources to be able to build a clone its a lot of fn very time consuming but the satisfaction from winning on something you built your self is way cool.If you dont have the resources to build I highly recommend buying one from Stump or Joby     ( Superior) while I havent met either in person I have had some internet talk with both and I feel both to be quaility people. I have not had any interaction with the other folks so I cant speak of them. My original build has was on this site some where in the charcoal smokers threads several years ago .I havent been here for quite a while and it sure looks like the site has grown very nicely.


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## bbqhead

check out this site, prairie bbq assocation, they have a lot info on clone's of gravity fed smokers.


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## coz

And they are great group of guys.


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## smoke_chef

Coz... I would love to hear how #4 turned out. I'm in the early stages of research for a RF GF smoker that would be big enough for whole hogs. Any thoughts?


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