Archimedean drills work by having a moveable surround push down a spiral handle to turn a drill. For the small size drill bits used for miniatures and models, you brace the drill with your index finger, while you use your thumb and middle finger to slide the driver down the spiral to turn the drill. It sounds awkward, but this allows you to drill small holes (up to 1mm) with one hand, unlike pin vises or small hand held drills which need two hands to operate. The most efficient Archimedean drills have a return spring, which resets the drill after each push (and also reverses it automatically out of your drilled hole).