Ergonomic Door Knob Lever, Fully Parametric

This is an adapter to convert a round door knob to a door handle with a lever, inspired by the design by tbirdrv. I redid this concept from scratch in OpenSCAD so that the dimensions can be fully parameterized to fit various door knob sizes with a close match so that the pieces line up.

I am fond of smooth ergonomic 3D printed parts, so this design calculates a curved hand-friendly structure with smooth rounded edges. This results in additional calculation time for OpenSCAD to render the fi