Clamp on Cup Holder by Seth_aka_Seth on Thingiverse: https://www.thingiverse.com/thing:4052536

Summary:
Easy to clamp onto your desk so you don't spill your drink on your valuable stuff. 4 inches in diameter. Can easily fit any cup.Update: For the cup holder part, print the corner parts with higher infill to prevent the splitting of layers as you clamp down on stuff.