The throat should be equal to the FB to cc opening. You could go a little lighter, but that is the spot that takes the abuse from the fire.
Of course these are my opinions, and they usually aren't worth much.
BBQ is just smoke and beers!
Usually more beers than smoke.
Your going to make a nice cooker it sounds like. I would say that the size of the throat is very important to use the calc and you can go just a bit larger, and then on the other end of the plate to CC shouldn't get smaller than the other opening or more than 1.5x. As for the insulation on the firebox, it is my opinion the inside should still be 1/4" so that the fire doesn't warp it too much. The fact it is insulated doesn't change the fact the fire is hitting it directly. And for the pics your having trouble with there is a topic on the "Board Index" that will help you with "Forum Issues". If you want to get some plans contact Frank Cox and these questions will be taken care of for sure, smokerplans.net
jm2cw
Current Smokers: Backyard RF Offset and Hybrid RF Offset trailer rig with Cowboy cooker and fish fryer, always room for more........
Thanks for the information! I am going to get in touch with Frank for some plans. That way it will take the guess work out of a lot of the things that I am sure will come up along the way!
Can anyone tell me the rule of thumb on the spacing between the end of the tank and the chimney? Also, I have noticed that different people have their firebox inlets in a range of different places (closer to the CC vs on the FB door). Are there any places on the firebox that are a better location for the inlets than another?
I like my chimney as close to the end as I can.
As for inlets, if you can, I would use all 4 sides. The back may need a little design work tho. That gives you lots of options if the wind changes or whatever. The one I would definitely do is the door, it just works with the natural air flow.
BBQ is just smoke and beers!
Usually more beers than smoke.
And on the eighth day God created barbecue …. because he DOES love us and he wants us to be happy.
Current smokers: Egor (trailered RF) and Easybake (tabletop pellet drive)
Thanks for all the input everyone! We are planning on working on the smoker this weekend. After some delays we finally have the welder ready to go. First some practice then we are going to crank it up! I will take a lot of pics and post them next week.