AZ Barbeque.com
Smokers, Grills, Pitts & More => Smokers, Grills, Pitts & More General Discussions => Topic started by: AZBBQGRILLS on November 09, 2010, 07:26:19 pm
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Thought I would post some pics, give a few details and let Ted show you the rest at the next BBQ Event. This is a Offset Smoker. The Smoker Box has the capacity to hold up to 7 shelves. There are 4 shelves 22 x 22 that are 7.5 inches apart and the top three shelves have and extra rail for additional shelves to be added. We are not finished yet, there is a diffuser plate to be added at the bottom and a pan to catch the ash. Ted should be testing it out Wednesday.
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Looks interesting.
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Looks great I am looking forward to seeing it in action.
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OOOOAAAHHHH very nice work David you and ted have came up with something nice there. Looking forward to seeing it this weekend.
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Is it a gravity feed like the Stump's or Superior smokers??
Is it insulated??
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I would say not insulated.....when I talked to him in tuscon he was thinking along the lines of a blanket wrap for it. I guess he had heard complaints about insulated smokers in regards to the temps being too hot on hot days. So he was in favor of some sort of removable insulation.
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Nope it's not insulated. It's done and Ted is going to try it out tonight before the event. It is the same gravity feed chute as the Stumps. I plan to build one from 3/16 plate. Only concern is weight. As for insulated, I have located all resources to build it. I am going to wait for the result from Teds before proceeding.
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I would say not insulated.....when I talked to him in tuscon he was thinking along the lines of a blanket wrap for it. I guess he had heard complaints about insulated smokers in regards to the temps being too hot on hot days. So he was in favor of some sort of removable insulation.
From the original design, I would almost agree. But, with the side-car fire box, I think insulated would be the way to go. Is that two or three cents? ;D
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That's two cents. The lower box is the ash box the upper section is the fire box. We buil it large and made the ash box large to supplement the fire box in the event heat need to be added. I agree it will be interesting to see how well it hols the temp. The smoker box is 10 ga. The fire box is 3/16 along with the ash box. All doors are sealed. Thus holding in as mush heat as possible. I graduated from college with a math degree. I was going to calculate the heat transfer loss in the smoker box but the equation and throughout process was too much so I thought I would wait for teds results.
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I went to Davids shop today and got to see Ted's smoker, very well built for sure. Im still waiting to see how this shoot thing works I looked at it and am still confused a little. Guys if you want a grill built get a hold of David he is really good at it and can most likely build it if you can think of it.
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Thanks for the complement. I have some other ideas which I will get to one day.
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I guess there is something I'm not seeing from the pictures. I'll see it this weekend.
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Houston we have a problem. Ted fired it up and the temp hovered at 104. It appears that there is an air issue. The coals would not stay lit with all the doors closed. I don; believe that they should be insulated. Issues could lie in the way it is sealed or the air intake itself. I am going to do a little research and see what happens. More to follow.
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hey David,
I do have one question about this design:
what is the square looking chimney with a lid at the top on top of the fire box for?
the hole that gets into the main chamber looks a little small to push 250F of heat inside... my two cents
Martin
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That is where the charcoal goes. The idea is that the charcoal is poured into the "chute"and falls down as it burns. Search stumps or superior smokers for an example.
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wow, I am going to go to bed less stupid tonight... I have never heard of this concept for coals... very interesting.
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This is the concept. The side assembly that you see has three components. Top component is the chute, a holding bay for unlit charcoal. The second component is the firebox and the final component is the ash box. The lids are all sealed air tight. You start with a chimney full of lit charcoal and dump it into the chute then you poor the remainder of the unlit coals on top. and seal the lid to the chute. The reason for the sealed door on top of the chute is to keep the unlit coals on top from igniting. The air valve on the ash box keep the lower coals lit. I also feel that the heat transfer is too small. I side assembly bolt on in the event it failed. We could remove it and start again. Hope that explains it.
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Yes... I get it now... very ingenious!
with a large hole for the heat to get to your main chamber it should work much better!
I guess you can also put some wood chunk mixed with the coal to add flavor.
It sounds like a great way to get a good night of sleep during contest:):):)
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Yes that is the purpose SLEEP. Well I have started the redesign and should be able to try it out today. I increased the size of the fire box and thickened the wall. I also increased the opening into the smoker from 2.5" x 5" to 3.5" x 9.5". I could go larger by another inch. I should have a post up today on how the temp held. Is there a formula or chart that that would show how many BTUs you get per charcoal. I have used the Mesquite Lump and the Mesquite burns very hot. I am going to try some of this first then do a 10 pound bag of charcoal. Cheers
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Did not get as far as I thought and heading out of town for a week :( I got the new fire box built it measures 12 x 10 at 10 inches in height. I have increased the air flow and increased the opening into the smoker box. Your guess is as good as mine. Worst case it fails and I put a offset fire box on the rear and let her ride.
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sounds good David,
the way I see it is heat rise so it probably wants to go up your coal shoot but without any air opening at the top it won't or shouldn't anyway. But if the draw on the side is not big enough heat won't go to the main chamber in hurry.
I had to add an extra chimney on my rig after I added my upright chamber... mostly because when I run both chambers or when my main chamber is really full of meat I feel need more air flow... so far it has made a great difference.
let us know how it goes once your back!
cheers
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DAVID, the comparison on charcoal at the naked wiz site might have btu's !
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The smoker was brought to life today. After increasing the size of the firebox and increasing the inlet I fired it up. The temp increased but not as much as I expected. I was averaging 150 -175. Next I added another exhaust stack and BAM the smoker fired up to 375. I was reading a pamphlet on design principals of wood burning stoves and was discussing the issues with a colleague and through our conversation we both decided that another exhaust stack needed to be added. I added a 3.5 inch outlet. The temp rose rapidly to 275 in approximately 20 minutes. I burned 20LBS of mequite lump charcoal for 5 five hours maintaining a temp of 275 or better. The next objective is to steady the temp how it goes. I also found a excel spread sheet that has some excellent formulas to help in design of a smoker ie fire box size, inlet size, exhaust size and smoking chamber excellent reference. If interested I can post it here.
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David, I would be interested in seeing that spread
sheet. Always looking for more info with building
smokers. Chuck
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Any new pics of the mods you made?
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The only mod that was made was increasing the fire box size to 10L x 12W x 10H. The inlet the smoker was increased to 4 x 9 from 2 x 5. However, I would have to wonder if this was necessary. After adding the extra exhaust stake the performance increased drastically. All the air vents around the firebox that I added do not need to be there. The vent I placed on the door is the key. Ted has it and is running some charcoal through it. I ran about 8 pounds of charcoal through it the temp reached 200 and stayed steady. It will be interesting to see the results from Ted. I will get some pics soon. I could not up load the file send me an email and I when get it to you.
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David,
you could certainly make the inlet with an adjustable door if you think it's now a touch too big... I did that for my upright - a guillotine type door so that I can turn it off anytime I want or run it very low 160F holding temp and not worry about playing with my fire.
just a thought
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Yep I know the concept you are speaking of. With my vertical smoker with the firebox mounted beneath the cooking chamber I have a door that can be closed off. However, in this concept the air flow adjust the temp very . Which I find really nice as you can shut it down by limiting the amount of air flowing into the fire champer. I works very well. Now I need to experiment with it to record changes. I will be building a double walll insulated smoker next. I am just trying to work throught the design process. The bottom seems to be the difficult part. How to trap and drain the grease.
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Ted fired it up on the coldest night he could. From what I was told it was fired up at 615pm and ran until mid night. The temp stayed at 260 through out the burn. The concept works. Now to refine it.
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Wonder how well she would work up here when it's 16 out. ??? Below 30 is the over night norm this time of year. :) probably burn a bit more fuel.
Sounds like you heading in the right direction! ;D
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Insulated would be best at temp you describing. Got the materials and know how. Just need to build one.
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Ted fired it up on the coldest night he could. From what I was told it was fired up at 615pm and ran until mid night. The temp stayed at 260 through out the burn. The concept works. Now to refine it.
Sweet sound like it might be working out!
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First big cook on the gravity feed smoker built by David. Started two Charcoal Chimneys. Once coals were ready poured down the charcoal chute. Filled the chute with 1 1/2 - 23 pound bags of charcoal. In about 1 hour and 30 minutes smoker was up to temp. Loaded the smokers two bottom shelves with 8 butts, 4 on each shelf. Top shelves were loaded with 2 large briskets per shelf. Smoker ran about 225 to 250, there was a 25 to 30 degree difference in the top shelf and the bottom shelves. The top shelves ran cooler. Didn't have to adjust vents at all ran steady. Cook was going great! Until.. some how the vent got hit closed, came out to find the temps had dropped down to 160. Opened vent backup and it took a couple of hours to get back up to temp. defiantly would have missed turn in. Lesson learned! Sure added time to my cook. Charcoal chute worked great. Briskets and butts were great. Found one hot spot were the heat first comes into smoker box. Very pleased with the performance of the smoker!
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Modifying the Gravity Feed Smoker. Making it rear mounted, firebox longer and ash box smaller. I hope to see improvements in the time it takes to heat up.
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Modification complete. GF System rear mounted, lighter with larger firebox, chute bigger 30+ pounds of charcoal, ash box smaller. Swivel caster instead of fixed wheels. Moves very easy. Nice improvement. Now to wait on testing.
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Thanks David. Its always nice working with someone who really knows what their doing. It looks great and is a lot easier to move around, will sure make transporting easier. We will be doing the test run this weekend. Will let you know how it goes. Thanks!