I’ve been using a cheap mini rotary tool for a while now, and I’m very happy with it. It’s quite a bit better than the finger nail polishing ones. I modified mine by drilling the collar’s ID a little larger so that it could accept a Dremmel 4486 keyless chuck. You can find these sold under a variety of brand names and colors. They have a micro-usb port for charging, the battery lasts a reasonable amount of time, they have 3 speed settings, and is great for small projects.