I built a vertical reverse flow offset a few years ago and after a work competition where I tried to smoke 8 racks it became clear it was too small. I started looking into buying a pellet smoker for the convenience since I have two small kids. Then I decided to build a pellet smoker (first 4 pictures) which worked well and held temp great but the smoke profile was less then I wanted so I got rid of both smokers which were only 75% complete and moved on to a gravity build.
On to the gravity build. Here is what I drafted out in CAD and followed it roughly.
Took a week off and got quite a bit done in that time. Here's the 1.5" box frame.
Firebox and charcoal chute are 1/4". CC is 1/8" and outside is 1/16".
1" C channel works great for the cooking grates.
Starting on CC door.
Getting the wheels all level and tacked up.
This was a huge minestone! It can roll!
Tadpole 1.5"x0.5" gasket.
Lots and lots of grinding.
I really liked this way of doing the gaskets, super rugged.
Just used High Temp Grill Paint from Rustoleum. I didn't want to have any high tech coatings that I couldn't touch up myself if I need to modify later.
I taped off where the gasket will meet the surface and will need to keep this oiled. I should have gone stainless for this like the big guys do. Oh well.
Test fitting the racks.
Diffuser I came up with. Probably overkill but gives a nice even temp.
First test with ball valve shutdown in place. Trying to figure out the size fan that will be needed for combustion.
Turns out this grate was too restrictive and ash was building up on it.
New grate design, works awesome.
Insulated controls cabinet, with 3d printed fan adapter. This gets changed later on.
Using a Velocio PLC and their 4" HMI touch screen.
Ball valve is there as a safety to shutdown and at end of cook.
3D Printed another duct to take air from the outside. I was getting a lot of off gassing in the control cabinet and I didn't want that to end up in the food.
Now it will suck fresh air from the front of the control cabinet cover.
Last bit of painting.
All done... nevermind the flat tire...
USB cables sticking out the inlet grill for control cab cooling fan temporarily so I can make adjustments for the next few cooks.
That's it for now. May make some adjustments but it's pretty much done.
On to the gravity build. Here is what I drafted out in CAD and followed it roughly.
Took a week off and got quite a bit done in that time. Here's the 1.5" box frame.
Firebox and charcoal chute are 1/4". CC is 1/8" and outside is 1/16".
1" C channel works great for the cooking grates.
Starting on CC door.
Getting the wheels all level and tacked up.
This was a huge minestone! It can roll!
Tadpole 1.5"x0.5" gasket.
Lots and lots of grinding.
I really liked this way of doing the gaskets, super rugged.
Just used High Temp Grill Paint from Rustoleum. I didn't want to have any high tech coatings that I couldn't touch up myself if I need to modify later.
I taped off where the gasket will meet the surface and will need to keep this oiled. I should have gone stainless for this like the big guys do. Oh well.
Test fitting the racks.
Diffuser I came up with. Probably overkill but gives a nice even temp.
First test with ball valve shutdown in place. Trying to figure out the size fan that will be needed for combustion.
Turns out this grate was too restrictive and ash was building up on it.
New grate design, works awesome.
Insulated controls cabinet, with 3d printed fan adapter. This gets changed later on.
Using a Velocio PLC and their 4" HMI touch screen.
Ball valve is there as a safety to shutdown and at end of cook.
3D Printed another duct to take air from the outside. I was getting a lot of off gassing in the control cabinet and I didn't want that to end up in the food.
Now it will suck fresh air from the front of the control cabinet cover.
Last bit of painting.
All done... nevermind the flat tire...
USB cables sticking out the inlet grill for control cab cooling fan temporarily so I can make adjustments for the next few cooks.
That's it for now. May make some adjustments but it's pretty much done.
