M42 and T2 screw caps for cameras/lenses/extension tubes

M42 and T2 extension tubes and adapters usually are sold without protective caps (same for bayonet/thread adapters and the like). This may be ok for initial transportation, but if you have configured a setup to use those items that you don't want to disassemble for storage, dust protection is needed. That's what these caps are for.

I used my photo thread library for Fusion360 to design these and recommend you read the slicing instructions and filament choice consideration on that page if you want to print these caps, however, I added PrusaSlicer 3MF files with preconfigured layer height variations for the caps as well.
Btw, since one cap only uses about 2 m of filament, these are good objects to print from those as-good-as-empty spools we all frequently have. 2 m equals about 7 windings of filament at the “bottom” of the spool.