Originally Posted by howardcano

If we accept that these would be only approximate results, then you are correct. You can find the stall torque by just connecting a lever arm to the motor shaft, rest the other end of the lever arm on a scale so that the force from the arm is normal to the scale, feed a known current into the motor, read the force on the scale, and calculate the torque. Repeat this for several angles of rotation of the motor within each commutation position (since the torque varies with rotor position), and again for the other commutation postitions (6 total), then average all of the results. This of course assumes that the torque vs current transfer function is linear.

Wow, that still sounds like a lot of work just to get approximate results!