Related cool diy-ish optical stuff...

A friend sent me this simple design for a raman spectrometer [1].

And some 3D-printable cage optics for when alignment is really important [2].

[1]: https://hackteria.org/wiki/images/a/a0/MobPhone_RamanSpec_20...

[2]: https://www.sciencedirect.com/science/article/pii/S246806721...

I remember that paper! I wonder why they aren't using modulated light?

It seems like an ESP32 camera could handle everything pretty cheaply, why is this not a thing you can just buy for $50 on Amazon yet?

Tangentially related: https://openflexure.org/

Very cool, but I wonder how far you get with something like this:

https://nl.aliexpress.com/item/1005004262524839.html

It's not motorized and motorizing that type of stand is painful (there is at least one paper that shows it's possible; I tried it and the results were not great: https://journals.plos.org/plosone/article?id=10.1371/journal...)

What was the biggest challenge? I suppose you get some unpredictable backlash in that flexible shaft.

Yeah the flexible shafts were terrible. I'd get highly variable movement even when making movements in only one direction (IE, home to Y 0, then only move positive ). They were so bad I tried to find ways to mount the steppers directly on each axis, which means the Y stepper is hanging out in air putting a lot of weight directly on the Y stage.

Instead, i switched to cloning stages like this: https://www.asiimaging.com/products/stages/xy-inverted-stage... but I used off-the-shelf (well, amazon) linear rails, off-the-shelf (stepperonline) steppers, and 3d printed (or machined aluminum) frames. Works much better.

For those interested, there is also OpenUC2 on this niche: https://github.com/openUC2/UC2-GIT It would be interesting to see how the two systems compare.

what is the best plastic to print these lenses from? I've found over time all of the clear prints I've don't suffer from UV degradation.

I don't think this project has you printing lenses- it wouldn't really make sense. It's very time consuming to print lenses. If you are going to do this, it makes more sense to print a mold and then cast resin (even then, this only really makes sense if you need a highly custom shape and are making multiple copies). See https://www.instructables.com/Making-Custom-Lenses/ https://formlabs.com/blog/creating-camera-lenses-with-stereo... https://www.instructables.com/Resin-Casting-Lenses/ i would use UV-resistant epoxy casting.

TRIZ says to solve it with ablateable materials- thin foilsheets with a evaporating binding agent - there are uv-resistant plastics https://topas.com/uv-transparency/ even transparent ones, but they are not printable.

Actual recommended technique: grind it https://hackaday.com/2023/11/16/a-3d-printed-grinder-for-pri...

It’s for teachers and their students, so presumably they don’t need it anymore after the class experiment is over and durability isn’t a concern? And they could always print it again.