I hope this could be helpful. This is my first project on thingiverse I made this knob out of PETG but I can't see why I can't be made out of PLA. This is a throttle knob for Zenith Aircraft Ch701 experimental I cut and threaded a 10-32 thread on existing throttle shaft and tap a 10-32 into the knob. I hope this will be a fun project for you.