This is the parameter knob for the metric screws I created for some projects.

It was written using OpenSCAD.

The attachments are the STL files of M6, M8 and M10

You just need to edit the first variable to generate a new knob design. If you don't like it, you can use a script to edit the different diameters.

$bolt_size - the sizes of bolts M6, M8, M10, etc.

$knob_nr - This number defines how many grooves the knob will have.

$bolt_height - This is the height of the bolt cavity, measured in millimeters.

$knob_height - This is the height of the knob, measured in millimeters.