This small, easy to print piece can be put onto many different lengths of M5 screw to create a CNC hold down screw. You need to use Socket Cap screws in order for these to work well. The hole on top is undersized to allow the screw to be pushed into it with a little bit of heat.

How to install:

I used a heat gun to heat up the screw, then quickly pushed the 3D printed piece up from the bottom and onto the screw. Similarly, you can use a soldering iron to heat up the screw, but in my experience it takes a lot longer to do this.

I would print with at least 4 walls, if not more. This allows the screw to have sufficient plastic to grip on to. I haven't had any of mine break loose.