Fist of all I have to say "Optimus-prime(rib)" is superb!
Second of all, I have to ask: Is this for a restaurant or catering service? There is space for smoking a lot of meat in it!
Third of all, I would incline for a fire box, not on the back position -when it is upright- but on the side position. And I say that for two reasons:
1 I think it can be easier to clean the ashes from a fire box than from the upright cylinder.
2 A fire box can be used to grill on it. [Second function for Optimus-prime(rib)]. You could even have the grill dis-mountable and have the smoke box made so it accepts it in two positions at 90 degrees from each other so you can grill even when Optimus-prime(rib) is at the transporting position.
I can see a safety issue when pivoting from and to the upright position. I can imagine the wheeled structure tending to roll on you or even pivoting suddenly to an upright position just like the cylinder. To prevent this from happening thee should be a counterweight or an equivalent means to fasten the cart at its position -on the ground and horizontally restricted from movement-.
Just my suggestions. But all in all grrrreat!
Edited by isosa - 11/7/12 at 12:03am