first RF smoker drawing/build

[Tospy]

Finally getting started.
Got a Air pressure tank from a friend, 130g (27.5"x40" +ends).
The idea is to build an RF smoker.

Using the pit calculator gives me following numbers:

CC= 130g

FB = 24"x 24" x 20"

Throat / opening FB to CC = 92.16inch²

air intake 10" x 4"

Chimney 4" x 4" x 37"

started drawing things up and found some issues/questions.

When I compare just the "looks" of my design it seems like my FB is to small. Or do I just imagine that?
The opening from the FB to CC is sligthly bigger then the calculators given me.....99inch² in stead off 92 inch². Throat will be the same.


Some pics.....Hope you guys can give me some support as I'm a bit stuck with those things.
Greetings From Belgium!!

[mp4]

It looks right to me.

The throat is the opening from the firebox to the cook chamber and it's OK for it to be bigger than the calculator states. In your design I would suggest your reduce the size by making the throat hole shorter. You'll have a lip under the baffle plate and that's a good thing - it helps reduce the hot spot on that end of the cook chamber.

The baffle plate gap should be no more than the designed throat size and can be 25% smaller. I made mine slightly smaller and it works great.

I hope this helps!

[Tospy]

Thanks MP4...

Adjusted it in the drawing , recalculated the throat and now I'm spot on with the calculator (93 inc²).
as you said I created a small lip....

[Dirtytires]

Good call on making it the proper size....following the calculator closely is key to a well running pit.

[Tospy]

Heading on with the drawing...

Still having doubts if I should place a butterfly air inlet in the door or not. I'v read that it could have a positive effect .....something about the draw etc....can't find the source off this info anymore...What do you guys think?

Main parts or know ready to make cut files so....soon....welding, welding ....welding

[towtruck]

Plans look good. I can't see adding an intake on the door as you have them on the sides already.

[Tospy]

Somebody just told me that air inlet in the door would be better than air intake on the sides of the FB......any experience with that?

[Big T]

The location doesn't affect the performance because the air isn't being forced through the cooker it's being drawn through the cooker by the hot air going out of the stack. I believe that it is better to have intakes on both sides because it gives you the option to close off one side and open the other if you get wind blowing directly into the intake.

[Dirtytires]

Ditto, both sides better in my opinion. As long as they are at/below fire level it really doesn’t matter which of the 4 sides it’s on.

[Tospy]

Thanks for the feedback guys!!!!
Just one more question ....

Now the exhaust is 40 inch long (4"x4"), is shorter and wider better or will this be ok? have a round pipe in stock that is 6.2"....but then the length of the exhaust should be shorter....

The air pressure tank

my plasma cnc

the next project

[Big T]

It's based off of volume so either will work fine. I like for the exhaust to be tall enough to keep the smoke out of my eyes but not so tall that it won't fit through the garage door.

[Dirtytires]

Not to mention that super high just looks funny.....imo.

[Tospy]

Thanks Big T....

Have been cutting and welding today...assembled the air intakes and welded up the firebox.....Not the most beautifull welds but they will do I guess.

Tomorrow I go further with the hinges and the door....

ciao ciaao

[Big T]

Don't beat yourself up, those are some nice beads.

[Dirtytires]

Welds don’t need to look pretty. They just need to secure 2 pieces of metal in a safe and functional way!

[Tospy]

Made some progress today....

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[Smurf]

Looking good

[Tospy]

HI builders,

Have been working on the cookingchamber today....starting to look like a smoker....next is the BF (and getting to the shop for welding gas)

Have a nice weekend!!! (mine is great....porc belly on the weber kettle..)

[Dirtytires]

Amazing how that gas always runs out on Saturday morning!

Keep it up.

[Tospy]

As the smoker must be movable.....more pics coming soon

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[Tospy]

Hello builders,

After welding the steering cart it was timz to put the larger parts together. Finally I got my welding table free again.

Today the stainless steel arrived for the racks [emoji847]

BUT....now I'm a bit stuck. Really don't know what to do with the smokestack.
Initially I wanted to install the chimney where you see the round hole above the fb.
I putted som square tubing in the tank to simulate the height off the bottom rack.

Do you guys think this is the right place or??? Should I install a collector? And then ....I have 4inch and 5 inch square tube and 6 inch round pipe....which one should I use?Really not sure about all that.



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[Big T]

You could ask 10 guys the same question and probably get 8 different answers. I'm personally not a fan of the stack being so low in the CC, I mount them as high as possible, either on the end or top. If you want to mount it at that height then I see no problems using the existing opening as long as it is equal to the size of your stack. As for the diameter, I would run them through the calculator, get a length for each and see what works best for you. I like the stack to be tall enough to keep the smoke out of my eyes but not so tall that it doesn't fit through the garage door.

[Tospy]

Thznks big T......thats where the doubts come from lot off different opinons in the internet.

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[Big T]

[Dirtytires]

I’ve had a low mounted stack and never did like it. Mine is now high at top dead center.

How is your counter weight working? It appears to be much taller than most and only raked back a couple of degrees. How well does it function for you in keeping the door balanced throughout the entire swing? I would think it would pull the door open pretty hard and then be pretty heavy to close from looking at it.

Just curious and hoping to learn from your design.(Or, it could just be the angle of the photo has distorted reality a bit, lol.)