Fancy scalloped knob

Customization

This model can be customized in the OpenSCAD customizer tab. Open the CAD file in OpenSCAD and unhide the customizer window. It can easily be modified to fit various sized shafts and to have different dimensions. 

You can change the diameter, height and corner radii. You can also change the number of scallops and their size.

Note: Use a development version of OpenSCAD to get access to the new manifold rendering engine or it will take forever to render

Wrench

If you really need to yank the knob hard there's an extra wrench model that snaps onto the knob and gives you more leverage. It's of course also customizable, and automatically adapts to any changes you make to the knob itself.

Print tips

Print with the large top face on the bed. Make sure to enable the ‘external perimeters first’ option to get better dimensional accuracy on the mounting hole.