[jason701802]

Another option is to find a drill that uses a similarly sized motor (you didn't say what size you are looking for) and replace the included motor with a BaneBots motor. Drill transmissions, in my experience, tend to have around 40:1 or 45:1 reduction in low gear which could easily be reduced further via sprockets. when looking at drills, take the motor that you are going to use with you so that you can hold it up against the back end of the drill and look through the vents to compare the size. We used an old Milwaukee drill for our RS775 motor. The shaft of the original motor was bigger than that of the 775 so we had to machine an adapter that we pressed the original pinion onto which we then pressed onto the 775.