M3 thumbscrew

This a redesigned version of James' thumbscrew http://www.thingiverse.com/thing:874155.

The piece he posted did not fit the nuts I was using so I created it to fit a nut with a 5.5 mm inscribed radius (from hexagonal flat to flat) or 6 mm circumscribed radius ( hexagonal vertex to vertex).

My printer did not provide as good a top finish as the original thing and so I made the numbers on the top protrude outward rather than cut inward.

It prints flawlessly with a 0.1 mm layer height and 15% infill on the PLA I am using. If the nut doesn't easily fit, I find placing it on a heated bed for 5 minutes at 100 degrees C and then wedging it into the soft PLA works well in fitting it in and also locking it from falling out.

Future mods include making it thinner to allow more travel on the bed height adjustment screws, and increasing the texture roughness on the barrel of the screw.