Shorted Turns Tester

It is called Growler.

Very simple design.

Core in V-Block shape.

Windings according to Supply line.

Place the armature in V-block and a fine iron strip, I used a hand-saw blade.

touching near edges of section to section.

the shorted one will not vibrate the blade.

Though the picture is not clear but you had been using it.

The version you show is for armatures.There is a smaller hand-held stator testing unit that incorporates the flexible metallic strip on the tool.It is moved around the inside of a stator and achieves the same degree of testing.Sorry I don't have any images available at this time.I think I still have one laying around the shop somewhere.I'll try to locate it and send a picture.Over the years, I have found that the ball bearing trick works just as well and is quicker and simpler to use if you have the motor already disassembled.

For testing a fully assembled motor, the "Ring Tester" ( a device that sends a pulse into the field coils, or stator, and measures the decay time, or "ringing" of the circuit) is quicker for determining triage of multiple motors, or for intermittent problems.

This can be done with an "O SCOPE" and a pulse generator as well, but we have to use the tools available, and sometimes improvise on the fly,such as the ball bearing method.