Makes round or square buttons with round or square shaft holes.
Adges can be rounded and beveled.

Square holes are keyholed to prevent rounding of internal corners
Tops of holes are vaulted so no support will be needed inside them.

Default is to make replacement buttons for Atlas stove
Button is a 10mm round button press fit onto a square 3.3mm shaft
this is a standard size for "isostat" switches

Print fairly fine as internal hole is small. I printed 0.25mm.
Print top up, as vaulting (45deg) of holes means no support will be used inside.

HoleOS parameter allows you to trim the internal size of shaft holes. My UP printer tends to make holes too small, so this is eg 0.3mm for round holes. Oddly square holes needed 0.0