Heavy duty desk clamp with smooth swivel

I made this from scratch to be compatible with the RostaP Multifunction Arm System. I wanted a stronger desk clamp and the ability to freely swivel the base without the teeth getting in the way. I also eliminated the need for one of the base discs. The clamp works on desks ranging from 5/8" to 1 3/4".

Two desk clamp versions are provided:

• One has matching 25mm threads on the top and bottom, which eliminates the need for one of the “base-with-hollow” discs from the original model by allowing the disc to be bolted directly to the clamp.
• The other is provided for backwards compatibility with the original “base-with-hollow” part, so if you already have the base discs printed and you just want a thicker clamp, you could use this one.

I recommend printing the clamp with thin tree supports or similar so the overhang threads don't get too rough.

The bolts all have the same beefy thread specs, and minimal overhangs for cleaner printing even with PETG. When printed with PLA+ or PETG on my Bambu X1 Carbon, the bolts fit perfectly into the female threads with very little play. Your printer or settings might yield different results. A little wax makes them move better.

The long bolt for securing the clamp to the desk doesn't have any metal reinforcement because it doesn't need it, but since either of the shorter bolts would be at a high-stress point, I added two holes for gluing-and-screwing in a pair of #7 x 1 5/8" trim-head screws. You could also just epoxy in two pieces of wire. The screw heads will never be seen once the clamp is assembled, so it doesn't really matter what it looks like. This is the size of screw I used: https://amzn.to/3H2Ffyu (Amazon Associate link).

This is a from-scratch build to make a beefier desk clamp with a stronger bolt, and a toothless base disc that allows for smooth rotation and bolts directly to the desk clamp.