Summary

Thumbwheel for M3 standard and nyloc nuts.

Used for levelling the bed on a Prusa Mendel.

Designed to be a tight fit around the nut so it doesn't fall off.

Instructions

There are 2 STL files, one is for standard nuts, and one is for nyloc nuts (which are higher than standard nuts)

Both STL files are generated from the one OpenSCAD source file. It is parametric and you can adjust the center hole size, and nut heights etc. You'll also need to download regular_shapes.scad which contains the modules for generating the hexagons.

The photo shows how i used one nut of each type, nyloc nut with thumbwheel on the bottom, and standard nut at the top of the MDF platform for extra locking down.

It is designed to be a tight fit, so add a bit of superglue to the inside of the thumbwheel (where the nut face meets it), and press in the nut, or just give the nut a few taps in with a hammer.