I made one that was 8 ft long, 4 ft high and 3 ft deep. It used a 2" x
2" x 16swg base frame with 1" x 1" x 16swg slats about every 12", the
legs folded underneath and the catch area was in rubber sheet. The upper
assembly dismantled for storage and the front panel had 4 hand holes
with elasticated entries to seal to the elbow length rubber gauntlets
worn. The window was just pallet film held on with magnetic stip. The
film was changed periodically. The main issue with the film was dust
sticking to it due to static, used to get some nice 0.25" or more
discharges occasionally. Due to limited space the whole thing could be
dismantled and stored as 8ft long x 4 ft high x 6" deep, easy stowage
against a wall.

WJ wrote:

Has anyone ever made one? They look pretty simple: Enclosed cab with
sloped floor, grate for the parts to be cleaned, siphon tube and air inlet
for the gun, Plexiglas window, glove holes and some kind of protected light.
Oh yeah, and an outlet for a dust vacuum.

Am I missing anything?

Walt