The clamps I have made are inspired by the "Oops Clamps".
They are designed to be used with a threaded table to clamp down stock on your CNC.
You can use the straight angle to unable your stock to slide underneath the clamps.
I have made the holes of the steel bars slightly undersized to be fit the bar tightly but you might check the accuracy you get out of your printer.
Rafts:
Doesn't Matter
Supports:
No
Resolution:
0,1
Infill:
50
Filament:
PLA
Notes:
Additionally you will need for each clamp that you print :