I wanted to buy a gem faceting machine, but at $6000 dollars each I decided I'd rather make my own. The machine works by holding the gemstone at specific angles and heights against a grinding plate. I designed and 3d printed the arm to rotate and move in 5 DOF in order to get any angle of cut you could want, and added a water tank for the grinding plate to make for smoother cuts. If you where to imagine the gem as an airplane, the bearings allow you to control the yaw, pitch, and roll, while two sliding joints allow you to lock in a specific height or distance from the grinding plate. For the grinding plate, I 3d printed a gear and rod to decrease the speed of an old AC kitchen appliance motor. The gem I’ve included in the pictures and video is quartz.