A while ago I posted a picture of an engraved badge that I traced out. These are the engravers I made to do the badges. The one on the left was what I used to make it and I just made the second one today. They're powered off a 2 cell 500mah lipo battery that will run them for more time than I have to watch them. It easily ran for a half hour when I made that badge. I also found a metal pinion gear that I may try using later. The red thing stuck to the battery is a voltage alarm that goes off when either cell gets low. It's VERY LOUD! It's designed to be heard over the high-pitched whines and humming of large brushless motors in planes and helicopters, so it is definitely a little bit too loud for this.