"Bushy" wrote in message
...
When I did my time in the army as a sparky, they had an alternator test
stand that was an off the shelf design.

It had a vice type clamp to hold almost any model of alternator, generator
or starter motor I ever tried to mount on it.


I took an alternator I had bought at a flea market to test at the local auto
parts store. It was a 100-amp 14-volt unit. The bearings seemed to be a
little rough if you spun the shaft by hand. They hooked it up and clamped
it down. The arrangement for the room's alternator test equipment was that
once they got it spinning they would flip a switch to excite the magnetic
field and then could read whether it was making sufficient voltage. As
soon as the technician flipped the switch, and as I watched through a window
from inside the store, the alternator tore itself away from its moorings and
flew into a wall. The wall, which was sheetrock, did not stop the missile.
It went on through, making a loud crash, into the parts supply section. As
soon as a load had been put on it the bearings had seized. If that loose
alternator had hit someone ...