I’ve tried designing a couple of 3D printed devices to help sort lego technic parts.

This one is a work in progress. It’s designed to sort axles and pins by length. It works OK, but there’s a reason these are always motorized. Try it on Thingiverse.

Here’s a grate/sieve for sorting pins and axles from beams and liftarms. It works pretty well, and is quick to print. It’s on Thingiverse as well.