[ausev] GE 11.5 inch motor

[Sarah & Erik]

Cool motor! The pictures of the commutator were a little hard to see
and they always are. As far as I could see it looks pretty good. A
couple things to look for-

put a finger on a brush and rotate the motor and feel for any clicks.
This will be a raised commutator bar

Look over the comm for even coloring

Check the brushes to make sure they're in good shape, no chipped corners

Also feel the commutator for raised or sharp edges.

Measure the resistance between the case and something in the normal
current path. It should be quite high.

If you take your motor in to a motor shop before you install it they
can turn and groove the commutator and clean things up if they need
it, but from the pictures your motor looks pretty good. Keep us
posted! If you do find anything you want fixed on your comm, take it
to a motor shop. I bought some of the light comm stones and tried to
even things up myself, and ended up making things worse.

Erik


On Jan 1, 2008 6:01 PM, Chris Robison <chris at chrisrobison.org> wrote:
> loopcat wrote:
> > Hey All,
> >  I took Chris R's advise and posted the motor pictures
> > to Flickr.com
> > Here is the link..
> >
> > http://flickr.com/photos/22369075@N07/
>
> Awesome. As I've recently discovered while trying to take post-mortem
> photos of Farver's dearly departed (hopefully repairable?) 10.7" Kostov,
> taking color-accurate pictures of a commutator is *really* hard. I'm
> going to guess that yours is still in good shape, from what little
> texture I can see in the photos.
>
> One thing I'm noticing -- the motor may be rated for its intended
> service at 70 volts, but by looking at the comm bars, it appears to be
> capable of handling much higher voltage without damage (of course,
> you'll need a battery pack sized to match it). Each of those comm bar
> separators gives you about 35 volts of dielectric separation, assuming
> typical construction. So from brush edge to adjacent brush edge, count
> them up and do the math. Any higher voltage than your result, and you
> risk fireballing the commutator, but below that is reliable territory.
> You may get much more horsepower out of this motor than we've been
> thinking. The only limitation will be heating, and that will be
> determined by how the motor is wound.
>
> >
> > One thing that concerns me, looks like the armature is
> > touching the winding a little. I hear a light "woosh"
> > sound as I hand turn the shaft. Is this normal? Any
> > advice would be welcome.
> > Thanks again, John in SA..
>
> The *whoosh* is completely normal. It's the sound of the brushes
> dragging on the commutator, which they will always do. It's one of the
> characteristics of a brushed DC motor, and the difference between DC and
> AC induction motors. On the other hand, the Siemens AC drive systems
> from MetricMind produce an intense very high-pitch whine due to their
> choice of PWM frequency for the inverter, so I guess the whoosh is nice
> in comparison.  :o)
>
> My Warp 13 actually makes a whoosh with a squeak in the background,
> which might go away once its broken in and the brown patina has formed
> on the comm bars. Either way, I'm going to guess that my differential
> will be significantly louder.  :o)
>
>    --chris
>
>
>
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