This can fit boards from 18mm to 50mm thickness (ideally this should be modified to support 16mm too, I will leave that for a future version, if needed).

Update 09/01/2022: I added a file for a body that supports a bearing on top and on the bottom too. I found that the drill bit was eating away the plastic at the bottom with the previous version, so the bearing at the bottom should prevent this, making the holes as straight as possible.

Print 1 body, 2 sides and 2 arms.

Materials needed:
2x 608 bearing (22mm outer diameter, 8mm inner)
2x 20mm M4 bolt
4x 40mm M4 bolt
6x M4 Nylon lock nuts

Printing settings:
I used PLA, 0.32mm layer height, 3 wall line count, 20% infill, with supports