A while ago I saw a TED talk about adjustable glasses. I wanted to build my own. This could eventually be used for eye glasses that are printed out or for a telescope or a microscope.
The biggest problem with this is making a seal that doesn’t leak around a plastic film. There were several designs I went through to get to the hexagonal pattern that I eventually published. Using the circular mating plates for the film never gave me a good seal all the way around. It turned out that since the printer doesn’t print thin lines accurately all the way around the circle, that the grooves in the plates wouldn’t ever mate up properly.
With the hexagonal parts I found that the groves printed out more reliably and mated much better. Still not perfect since it leaks, but a little RTV or Weldit can solve that problem.