This Self-centering 3-jaw Chuck is the simplest Chuck design. There are no pinions, no ring gear on the back of the scroll and no screws needed!! See my other Chuck designs for the more complicated 3-Jaw Chuck that needs many more parts but is the design of “real” steel Lathe Chucks. This print has close tolerances, be sure to have your printer DIALED IN. I actually got into the G-code and changed the bed temp profile to drop to 20°c after the first 10 layers to help avoid warping. BUT, I also hit it with hot glue around the sides at the bottom just for extra strength security!! If you’re using an adhesion method like a Raft then I would ABSOLUTELY turn the bed heat off after the first 10 layers and hot glue it in place!! Why? Well because the bed heat will melt the Raft to the Print and you’ll have to sand it off!! Ask me how I know. Lol!! 😂