Latest 3rd version is here (NO SUPPORTS NEEDED) https://www.thingiverse.com/thing:5167450

2nd version is here : https://www.thingiverse.com/thing:5147623

It has the cup holder separate from the clamp to allow different colors, and a stronger print orientation for the clamp.

March 3, 2021: Modified the thread with a coil for a more forgiving print. Also moved screw closer to cup to reduce flex during tightening.

Feb 19, 2021 Edit: added a thinner screw in case the regular screw is too tight. There are now two different size screws and a short test version for each. I'd recommend the regular screw first. If you decide to scale them in your slicer, don't forget to also scale the circular plate piece as well. Also added the STEP file for the regular screw.

Cup holder clamp. I have tried several other cup holder clamps and some had the cups sitting too deep, and some that were a good depth, but no opening for a mug handle. So I took what I liked from other cup holder desk clamps and designed this. I recommend at least 20-30% infill. I used 3 walls. I have included a test piece of the threading for the main body of the clamp and shorter test screws, so you can test your fitting if you'd like before printing the entire cup holder. If you have any problems with the screw threading, try scaling the screw by 1% as well as the rotating plate, but recommend leaving the square clamp alone. Just slightly modify the screw and plate together. With the screw at max open, the thickest size table this can fit is 30mm thickness. The diameter for a cup opening is 105mm.Clamp strength is quite well on this model.

You will need support for the clamp in between the two plates. I have tried both tree supports and just support on between the square clamps, and I felt that the support only between the square clamps was better. It pulled out very easily. If you use tree supports, just make sure you have good bed adhesion so they don't come loose. And MAKE SURE there are no supports touching the threads.

I'd really appreciate if you post your makes! Thanks. Let me know if I can help you at all.