A note on this design:
It looks like a fragile design, but once it is together, it is all pretty strong.
I did have one side crack on me when I took it out of the acrylic, so make sure you don’t stress the plastics. Especially at the very ends, if it isn’t completely out of the plastic, don’t force it out, be gentle.
Once assembled, everything fits well enough that the whole structure is pretty strong.
If you do crack one, simply print out another side. I’m sure everyone has had a little waste at one time or another.
I had one white sheet of Beta proof grade that was actually thinner than 1/8" by a little bit. It doesn’t take much. If you get a thinner sheet, the pattern will still work and the test tube locks it all in place. Take out the test tube and the whole mess can be taken apart and laid out in the flat for storage.
If you’ve got good tolerances on your material, it should fit together snug. Remove carefully and you should be able to take it apart and put it together without issue.