Items to enhance laser cutter/engraver

This is a crank handle that I created by borrowing part of a Volkswagen manual window crank and merging it with a fitting to go over the Z axis knob on the OMTech Laser Engraver/Cutter
This is the crank handle installed. It works great! Note the custom made magnets on the build surface. They help hold down lighter materials. The Grid below is iron.
This is a hold down attachment that I built with the help of Thingiverse. It is for the rotary attachment.
The hold down clamp in action. Without some pressure, the rotary wheels can slip on the bottom. This completely messes up the engraving.
The O-ring wheel on the end of the hold-down. I made this in TinkerCAD.
This is the first attempt. The final version got a wider base to give more room for the hold down screws.