Thumbscrew Cap for M3

I need about 40 M3 x 8mm thumbscrews as pictured in the comparison photo. However, they're a little pricey and take a month or so to ship from China to USA. So, I got out the 0.25mm nozzle and FreeCad and put something together to adapt a regular M3 socket head cap screw.

Why another thumbscrew cap? The few I found here that looked close would either have to be glued or risk falling off when used in outdoor, vibrating equipment as these will be. I was also concerned that they might eventually slip and spin around the screw head.

This design has some flexing arcs that gently cup in around the head of the screw and hold it rather firmly once seated. It is, however, still removable. If you find it slipping, you can squeeze through the two thin side walls to get better grip on the actual head.

With a M3 x 10mm SHCS, I get about 0.5mm less total height and 0.5mm more thread than the reference thumbscrew which suits my application nicely. If you would like additional height, adjust the height of the Cylinder in FreeCAD. If you want less exposed thread, you can increase the value of head recess in the spreadsheet.

Print Settings

Printer Brand:

Prusa

Printer:

Mk2.5s

Rafts:

No

Supports:

No

Resolution:

0.10 + Adaptive variable

Infill:

don't think there is any, but 20%

Filament: Prusament ASA Black

Notes:

0.25mm nozzle is probably essential here! I printed with a brim, too, just 'cause I didn't want to lose any of these on the plate, but that might not really be necessary.