These cups have an outer surface that is a helical gear. Each horizontal cross section (like the top surface) is normal gear. Each layer beneath is rotated slightly such that makes the teeth form a helix. Think DNA double helix, except with 12 and 20 teeth.
The second helical cup is also a cage gear. This means that the teeth are freestanding and only connected at the top and bottom. It is surprisingly strong and has very little deflection when squeezed firmly. The removed surface would not have contacted the opposing gear and therefore has no effect on smoothness when removed.
The cage gear was designed to hold your toothbrush so that it can drain extra water. The first cup (which I call "closed") is designed for pens at your desk.
Uses 2 standard skateboard/fidget spinner bearings.
608ZZ Shielded 8x22x7 Bearing
2 cups not enough? Check out this modular version that can handle as many cups as you want! Thanks tbutters! https://www.thingiverse.com/thing:2854179
There are 2 different assemblies- the "closed" gear cups and the "cage" gear cups. The cage gear is the one with holes in between the teeth.
To print either:
-Print 2 copies of the cup ONE MUST BE MIRRORED
-Print the base. Both bases fit on 120x120 size beds.
I HIGHLY recommend slicing with Slic3r because you can use the "Only infill where needed" option to eliminate unnecessary infill in the gear teeth and speed up print 2X and because I experienced issues with this model in Cura.
This print requires you buy 2 standard skate/fidget spinner bearings. The cups are designed to firmly press onto the bearings. If they are too loose, print 2 "bearing shims.stl". Set them on top of the bearing before pressing the cups on. That should make everything nice and snug.
If you really really don't want to buy the bearings, you can print this plastic bearing:
Or these spacers:
v1: Everything uploaded.
v2: Cage gear axis spacing increased 0.5mm for freer spinning.