Hi. I am so happy to find this active community. I have almost a year since I started learning how to make jewellery, went through almost anything from cutting, soldering, stone setting and so on. One problem I still encounter from time to time is the drill bit (especially ball burr or cylinder) slipping on the surface. I have a pendant motor so I can pretty much adjust the speed to any rpm.
One thing I noticed is that when using the ball burr or cylinder you cannot go that slow, like with a shank drill.
Do you have any suggestions on how to improve this and prevent it from slipping?