First smoker build

[Michael3869]

Hi, do you think this reverse flow smoker would work? Its going to be my first smoker build ever, what do you think about it? Did I miss something, is there something you would change?

 

[kruizer]

You should include a drain for rendered fats in the bottom of the cook chamber. Never mind, I see you have it.

 

[mrsmoklestein]

It looks like a great design to me, I see you REALLY like to design and weld though!

What is the advantage to notching the seams for the cook chamber, the firebox, and everywhere else on the smoker if you're going to weld?....do you have access to a CNC laser or something that you have engineered the living hell out of this thing? I DO see a problem with all of this notching because you're expecting this thing to fit like a jigsaw puzzle with raw steel.....and the problem is that AS SOON as you start welding on this thing, you're going to run into heat stress/shifting of your material. I do not envision this thing going together easily despite the seemingly great design....these smokers do not go together like plastic assembly pieces. They shift, they warp, they expand. It's better to keep your assembly method as flexible as possible because I will bet you that your notches will make it difficult.

I mean, we don't have dimensions but I can assume that this thing is going to be pretty darn heavy as well. If I learned ANYTHING from my 20" offset build, it's that big, pneumatic tires are your friend with these kinds of builds....if not a trailer mount.

You don't realize how heavy this thing will be until you get about halfway through...

Side note: Your firebox adjustment design should have a LOT of clearance on your pivot pins because you'll run into significant expansion inside the firebox.

 

[RiversideSm0ker]

I'm no engineer but that thing "looks" impressive as hell. I hope you can pull it off. Good luck with the project.

George

 

[kmmamm]

I think I understand why the exhaust tube is located where it is....( to avoid interference with fire box "grill" configuration?) but you are setting yourself up for uneven cc temps. If you can move the exhaust down and dump on the end above the FB, you will have better results. I have built a couple that are very similar to your FB design and was ultimately not happy with either of them. Sold one and scrapped the other

 

[Michael3869]

Ok, I understand, I have changed the exhaust a bit:

do you have access to a CNC laser or something that you have engineered the living hell out of this thing?

Yes, everything will be cut by a cnc laser with an accuracy of 0,2mm (0,03 inch). We always add these notches to save time during welding. You can put the whole thing together with just a few welding points on each part, and once everything is in place and cant move you do the final welding without any shifting from heat.

 

[mrsmoklestein]

Yes, everything will be cut by a cnc laser with an accuracy of 0,2mm (0,03 inch). We always add these notches to save time during welding. You can put the whole thing together with just a few welding points on each part, and once everything is in place and cant move you do the final welding without any shifting from heat.

However, you can't actually tack weld EVERYTHING in place and then expect to weld it because you have numerous interior, and overhead weld spots that are not accessible after its been assembled.....Go ahead and tack weld everything, I just think you'll be paying for it down the line. I spent three months fabbing on mine and wished I hadn't over engineered it. I deal with engineers ALL DAY, EVERY DAY in my line of employment and I watch them approach me with designs they think will assemble and function perfectly, but at the end of the day, they're not the ones who construct it and they don't have a clue how it will actually go together. I can teach anyone to run a 3D design software, I find it almost impossible however to teach someone how to fabricate well because it's not something that can necessarily be taught a lot of times.

Never expect engineering to overrule fabrication, and these smokers are great example of it. It all looks great on paper while you're looking at the screen running Solidworks or ProE....but it doesn't always go together that way. You can tack weld everything in place but from the very first full weld you put down, this thing is going to start moving.....just trying to warn you before you start. I design and run CNC machinery for a living and spend a lot of time fabricating my friend.

See your firebox door gaskets, and your cook chamber gaskets? You have to run a FULL interior weld bead on those puppies before they are affixed to the rest of the smoker, and THEN fitted with your tab design.....they're going to flex significantly, even with 0.25" steel. They'll warp from the heat, and they won't fit. Period.

Good luck.

 

[gmc2003]

Not a builder or mechanical engineer, but that design looks great. Keep us updated on your progress. When do you think you'll start the actual build?

Chris

 

[kmmamm]

That should do the trick getting the airflow and cc temps evened out.
Notching the steel for fab is an interesting but very detailed approach for one-off builds. Are you planning to mass produce this design?
Can your laser be setup to cut plywood? If so, I would seriously consider doing a wood mockup just to be sure things fit before committing to an expensive plate of steel. Mock build would also help identify potential subassembly candidates as well as flesh out some potential problems in the weld process.
As others have pointed out, even if everything is tacked tight, once you start getting medieval under the hood (without jigs and proper clamps to hold the pieces in place), things are going to move, twist and turn. That said, there are methods and processes such as stitch welding, blind welds,etc that can be employed to minimize (and to a certain extent) control unwanted piece movement without sacrificing overall strength.

 

[mrsmoklestein]

What I'll leave this thread with is this:

Don't bite off more than you can chew....and personally, this would be more than I can chew.

 

[weedeater]

Looks like a great design! I will be watching with admiration.

Weedeater

 

[Michael3869]

Progress so far:

 

[ab canuck]

It's all coming together. Looks good so far.

 

[Winterrider]

If it all works, looks like it would be awesome. Wish you the best of luck, and hope to see the final product.

 

[Michael3869]

Started working on the smoke chamber:

 

[kmmamm]

How is the steel behaving? Are you getting any distortion as you weld the parts together?

 

[Berettaclayshooter]

I appears that your constructing your smoker from stainless. While that sounds like a good idea, standard grade stainless will not take well to heat and warp like crazy, you need high temp stainless like grade 310. Also I noticed a lot of sugaring on the main cook chamber, I would suggest using a purge bar on the back side to prevent this. That seam will rust out on you because it was welded too hot and now lacks the chemical make up to prevent it from rusting. I'm a food/ phrama fabricator by trade. I work with stainless steel everyday, my best advise about S/S is it's a pain in the A$$.

 

[kingpapawawa]

I regret every time my grease trap is narrower than 2 inches.

 

[Michael3869]

I had some small issues with the steel warping, but no real problems so far.

Almost finnished now, next step is to add the wheels and small parts like the fire grate and water box.

 

[Johndeere1]

Very nice build. Impressive work.