This is a basic set of hold-down and cam clamps with corner braces to use for work-holding on your Shapeoko or other CNC.
I used Carbide Create to create the CAM layout for the clamps and tray. I used 1/2 inch MDF for both designs. The thumbscrew knobs (link below) capture a 1/4-20 carriage bolt and were 3D printed on my Prusa i3 MK3S.
Thumbscrew Knobs: https://www.thingiverse.com/thing:4645512
More info: https://youtu.be/ikzMXsjS9Ns
I used the Shapeoko 3 XL and the Carbide3d #201 1/4 inch bit