Math Drawing Compass Bullseye Style with Locking Mechinism

Update (5/1/26): I have updated the tension clip to be better at clamping. I have found it works best if the push the two sides of the compass in before tightening to get a stronger hold. If you over tighten it too much the slide layers may come apart.

I am a math teacher and needed a class set of compasses. I prefer the "Bullseye" style over the classic one but all of the ones to buy seem to break very easily. After testing a few 3D printable ones I found the one from Kezat was best. I adjusted a few things from his design

1. Made the center disk tighter. I have two models available in the file if the main model is too tight for your printer.
2. I added a small ring on the center disk to help center the compass.
3. I made the holes for the pencil smaller so it doesn't have the ability to move around as much when using the compass.

The best part of this is that if anything breaks you can just print a replacement part.

To put together:
Put the tension clips on either side of the slide that is printed with the compass body.
Add the knob on top and tighten.