Re: [CAD_CAM_EDM_DRO] Re: Bridgeport servo motors

braidmeister wrote:

>Scott,
>Unfortunately...It is correct...they ARE CCW...#$^%^(*()&$!!!!
>
>I just called them and the tech opened up the motor and looked at the
>brushes. He said that it did sound different running it forwards or
>backwards...BUT the brushes were angled...and there is no easy way to
>get them timed for both directs.
>
>WHAT A HUGE DISAPPOINTMENT!!!
>
>So now...back to freakin' square 1. I would be interested in other
>types of motors than these or the Ameteks (too slow). Anybody got a
>source for 3 that will work at a decent price? (Decent meaning better
>than $400 ea)
>
>SO here's a question for you people: Since Surplus Center advertised
>the motors as bi-directional, who pays for the shipping up and back?
>Why should I have to pay shipping on something that was falsely
>advertised?
>
>

No doubt the brushes are run in in one direction, due to the intended use
of the motors. But, that doesn't mean they CAN'T be run the other
direction.
You might have slightly faster brush wear with this setup, but it may be
almost
insignificant. If you run it both directions, the brushes will likely
change their
fit slightly, and the difference in sound will stop. It might be a good
idea to adjust
the brush holders (I'm guessing these are cheaply made motors, with stamped
brass brush holders riveted to a phenolic card or something similar.)
If the
brushes rock in the holders when you reverse direction, this will make
for poor
fit between the brush and commutator, So, you might want to make sure
the brush holders grip the sides of the brush well enough to minimize the
rocking. Other than that, they most likely will work OK.

As for return, if you lean on them, they might agree to a UPS "call tag"
where they pay the shipping to return the items. You've probably got a
couple days to research it and see if anyone is using them in reversing
operation
without trouble.

Why are the Ameteks too slow? Given a suitable power supply, I think
they can
do OK.

Jon