Parametric endmill index/holder

A flat, secure index (holder) for some cheap end-mills I picked up for cleaning support material out of recessed holes. Should be able to use the Customizer (in OpenSCAD 2019.05 or later) to match whatever endmills you have. Worked pretty well for a drill bit, too.

Insert the endmills at an angle, then push down flat. Little ridges help ensure a secure fit, even if you turn it upside down and shake it a bit.

To access a mill, push down on its bottom so that the tip pops upward and can be r