Hi Brian,
I don't have any plan to give to you but I can give you some tips that I heard over time.
- Some people take a big plastic box and put computer fan for the exhaust. In my opinion this is for little works.
- Then most people, I think, build their own with plywood or compressed wood, then they add a squirrel cage fan. Many people say that squirrel cage fan type are the best because the electrical motor as away from the airflow, so you avoid fire risks with thinner and all chemical stuff.
For your fun, mine is basiclly a cube. It's all plywood, except the front where I putted a movable (Up, down) Plexiglass plate, and the top is also a plexiglass plate to allow lighting. The fan is screwed on the back panel, covered with an aluminum pipe that makes a 90 degree turn, than plogued on a drying machine soft pipe that goes out by the window.
It's important that your exhaust pipe is wide enough for your fan, otherwise you'll get problems. Also the shorter is your pipe, the best it is because the airflow moves out more easilly.
For the dimensions and shape of the box....all depends on your needs. Mine is 2ft wide, 2ft deep and 18 in of height. Of course I don't need that much room to paint a 1/72 tank, even not a 1/35, but because I'm also in airplanes and love big ones, I made it big.
What you can do to get ideas is search for "spraybooth" on Armorama.com with the search bar on the top of the page. There are many people showing their own.
Good luck.
Philippe
Working on:
''Landing interval'' - Soviet infantry in Berlin, April 1945
Thinking on:
''Hände nach oben!'' - Canadian infantry in Caen, July 1944