fred via EV wrote:
I have a Gizmo EV which uses a 10" Sepex motor.
That doesn't sound like the original motor. I worked on Gizmos many moons ago, and as I recall they had D&D 6.7" series motors, and Alltrax controllers.
Many moons ago, I discovered a burned brush and guessed that it was due to low rpm, high current use by the previous owner.
That is quite likely. The Gizmo was geared too low, so hill-climbing and demanding fast low-speed accelleration was hard on the brushes and controller. The guy that owned the Gizmos I worked on had a pile of burned-up motors and controllers.
Adding a blower to cool the motor helped a lot.
More recently, the Gizmo has been sitting idle. Perhaps someone can tell me why it feels as though it is cogging at low speed, even though it didn't use to do that. At higher speeds, the jitter and jumping goes away, but the low speed regime is from zero to about 20 mph and is painful to experience. I've been told from one of the Gizmo group denizens that when/if I fix the jitter, it would be wise to take a spin every two weeks or so to keep the jitters away. Would the commutator oxide over non-use and cause this problem? Because I retained the previous motor with the burned brush, I figured I'd get it checked out, repaired or rebuilt as required, but it's nigh impossible to find a motor repair facility in this area. One of the more recently recommended shops now has a sign that says something along the lines of "I'll be here if I feel like it. Call me to see if I'm here. If I'm not here and I feel like working, I'll call you back." He didn't call back. Through the shop window, I saw a sign that stated he does not work on electric vehicle motors, although I think I could have slipped the ES-10C by as something else.
If the brush is all that burned, the commutator can be resurfaced and new brushes installed to resurrect the motor. This is not difficult work.
I have the address in NY from which I ordered the current motor, but the shipping would be brutal.
Where are you located? Are there any motor repair places listed in a city near you? Any place that works on golf carts, fork lifts, and industrial motors can rebuild your motor.
Is it practical to expect to be able to dismantle the spare motor, replace the brushes and then what?
If the commutator is straight and true (no bent or warped bars), you basically put the armature in a lathe, and take off just enough copper to clean up and smooth the surface again. Assemble the motor with new brushes and brush springs. Run the motor on the bench for several hours at low voltage to break it in.
Do I need to examine and/or replace the bearings on which the shaft operates?
Bearings generally last "forever". If they do need replacement, you need a press or gear puller. Again, that's not difficult to find.
In summary (whew!), is the spare motor fixable by a handy tinkerer?
I'd say it's worth a try. It's worthless if it's broken. How much worse can it be? ;-)
Is the in-place motor problem something that is easily identified and as easily resolved?
I can't tell. Maybe someone put the wrong motor and controller in it. -- I look for what needs to be done. After all, that's how the universe designs itself. -- R. Buckminster Fuller -- Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
