Quote Originally Posted by 3e8 View Post
Thanks for the link. Do you remember the approximate diameter of the tubes? I was thinking of using 3" or 4" PVC, but with 1/4" foam, I think I may have to go even larger for 40"x50"
4" is plenty for 30x40 (and was the size of the original Maxwell tubes), but a bit tight for 40x50. I just did a trial 40x50 rollup which created a roll with a 4.5" diameter. I am currently using 4" ABS pipe for my 30x40s. Once I am done refurbishing my horizontal enlarger (Devere 8x10), I planned to use 5" ABS for 40x50.

justus