I was having trouble keeping my A-MAZE-N pellet burner lit, so I did the mailbox mod. After doing the mod, I still was having trouble keeping it lit and never saw the thin blue smoke coming from the back opening of the smoker. I had several ideas as to what the issue is, but what it ultimately boils down to is the smoker's draft just seems to suck.
I set up to smoke some ribs today. With the propane burner off, it was drafting very well. Within seconds of lighting the propane burner, the smoke started billowing out of the mailbox. I cracked the door to the smoker and propped it open about 1/4 to 1/2 an inch. The smoke stopped coming out of the mailbox and started coming out of the door. I'm not too concerned about maintaining the temperature as I'm working on my own Raspberry Pi PID controller for the propane. With the door cracked, it is struggling to get up to 225ºF, it looks like it'll stall at about 220ºF but that is close enough that I'm not worried about it.
I've seen where people have added a vertical smoke stack to the smoker. Is that the best mod to improve drafting? Would moving the aluminum tubing from the mailbox mod to be lower on my smoker improve anything? I'm thinking that it wouldn't unless I moved the aluminum tubing to be under the propane burner. But even then I don't know if that would do anything worthwhile. In the picture below you can see where I've routed the tubing. It is to the left of the clean turkey roasting pan, well above the burner, iron griddle, and a tray of sand.