This is based off of the CNC clamps by DIY 3d Tech at: https://www.thingiverse.com/thing:4344869 . Use the instructions over there if you have any questions.

I made it because my CNC has a spoilboard on it and I didn't need the clamps to support the workpiece. I removed the workpiece platforms as well as put the pieces on a diet to make them faster and cheaper to print.

You can reuse the hardware that came with your CNC's clamps and add a few M5 bolts and wing nuts