Hi there,

I want to use 4 cordless drill motors to power a mobile robot, but I need some assistance determining the thread size of the motor axis. The motor is from a B&D cordless drill and when the chuck is removed, a thread is revealed. This is almost a standard thread on all cordless drills, but I can't figure out the size/type of it in order to buy a corresponding nut.

Approximate dimensions are
- Outer diameter: 12.5 mm (0.492 in)
- Pitch: 1.3 mm (0.051 in)

I guess the dimensions correspond to an American standard. Anyone with special knowledge on cordless drills?