Hello Fred,
Here is a chance to learn some motor testing and maintenance that you can
do, before having a motor shop doing a major repair.
Remove the armature and clean the armature and commutator with a motor
cleaning spray that you can get from from a motor shop or from NAPA.
You then test for a grounded communtator by placing test leads between each
communtator bar and the shaft.
You can make a simple motor test unit by using a 120 vac lamp holder, a 100
watt light bulb, a standard 120 vac 2 wire plug. Wire the black wire to the
lamp holder and connect another black wire to the other side of the lamp
holder to a test lead. Then connected a white wire to the neutral side of
the plug which goes to the other test lead.
1. Test for shorts between the commutator bars and shaft.
2. Test for shorts and conductivity of the communtator bars by
placing the test leads between each bar.
Note: Keep track of each bar that shows when the lamp lights up
and it does not. Each winding provides a return circuit
to the communtator bar which completes one circuit.
You are checking between each stator windings for open and
or shorts between these windings.
There should be a pattern or shorts and opens around the
communtator. A dc motor has may types of armature winding
methods as each coil lead goes to its own communtator bar,
two cols to the same bar, a coil winding goes to two bars
that is adjacent to each other, a coil winding leads may go
to communtator bars that may be connected up to 180 degrees
apart.
If you find that communtator open close circuit pattern is
the same, then the stator windings may be ok.
3. Take the armature to a motor shop and have them verified your
test. If the armature checks out ok, then you can either have
turn the communator, undercut the segments, re-enamel and provide
you with new brush set and brush springs.
Note: Some brush sets could cost up or over $250.00 if they are
are a double set and are silver-graphite type.
About every ten years, I do this maintenance while the motor is in the EV.
I first remove the brushes and brush springs and clean the communtator and
staror. I then clean out the commutator segments spaces with a under cutter
tool you can purchase from a motor shop or use a hack saw blade that I cut
in half and weld the two pieces together at a 90 degree angle of each other.
Use one of those single hacksaw holders to hold this blade.
As the communtator wear down, you need to lower the insulator between the
bars. I then give the edges of each bar a slight vee cut with a triangle
file which I also had to modified to a 90 degree angle.
Then I spray the communator face and the motor shaft up to the bearing
surfaces with motor enamel that you can get in a spray can from a motor
shop. The reason I spray the communator face and shaft, is to stop the
current tracking to ground which is cause by the brush dust. Using a small
artist brush, I apply the motor enamel on the insulator segments between
each bar.
A motor shop would immerse the stator in motor enamel and bake it. Then
turn the communtor to clean it up. Turning the communtor with a lathe tool
leaves a rough surface which will quickly fill up with the brush material.
This builds up between the communtor segments causing a decrease in
resistance between the bars. This is why I prefer the hard silver-graphite
brushes that are pre-curve and have the communtator micro mirror which means
turning the communtator surface to a mirror finish.
I ran my GE-11 motor with this type of finish and brush type from 1976 to
2006 with no problems doing this maintenance every ten years.
Roland
----- Original Message -----
From: "fred" <[email protected]>
To: "EV DL" <[email protected]>
Sent: Tuesday, January 25, 2011 9:02 AM
Subject: [EVDL] Shunt wound?
> I've had a setback recently in my Gizmo. It crapped out about five miles
> from
> home and had to be ICE-trailered back, but I've found the root cause.
> Broken
> brush wire on one of the brushes, stuck brushes on two others, and I can't
> get
> to number four without pulling the motor.
>
> The commutator looks pretty nasty, all black, but not burned black, so
> maybe it
> needs only a cleaning and trimming. I'm not sure what it's called when the
> bars
> are cut back to a smooth surface, but this one needs it badly. The one
> brush
> that came out is pitted.
>
> I've been in contact with the D&D motor people, as this is an ES-10C sepex
> motor. I was given a price for a rebuilt shunt wound motor. I'm hoping
> that
> means it's a sepex motor. Can someone confirm this?
>
> Is there any reason I would want a new motor (US$535) as opposed to a
> "re-worked" motor (US$380) when it comes to reliability? I certainly do
> not
> abuse my EVs and expect that this is a combination of circumstances, not
> necessarily abuse, but can't rule it out either.
>
> I'm pretty pleased to see a 3-5 day reference on the purchase, much faster
> than
> I expected and faster than I can get a battery pack and monitoring system
> in
> place.
>
> Alternatively, I can ship the motor out west (FL to OR) and have Jim
> Husted work
> his magic on it, but now shipping costs come into consideration, both
> directions.
>
> This is one of those times where I'm willing to pay to get the perceived
> value.
> I don't know what value to put on a re-worked motor, though.
>
> Opinions?
>
>
>
> -------------- next part --------------
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Here is a chance to learn some motor testing and maintenance that you can
do, before having a motor shop doing a major repair.
Remove the armature and clean the armature and commutator with a motor
cleaning spray that you can get from from a motor shop or from NAPA.
You then test for a grounded communtator by placing test leads between each
communtator bar and the shaft.
You can make a simple motor test unit by using a 120 vac lamp holder, a 100
watt light bulb, a standard 120 vac 2 wire plug. Wire the black wire to the
lamp holder and connect another black wire to the other side of the lamp
holder to a test lead. Then connected a white wire to the neutral side of
the plug which goes to the other test lead.
1. Test for shorts between the commutator bars and shaft.
2. Test for shorts and conductivity of the communtator bars by
placing the test leads between each bar.
Note: Keep track of each bar that shows when the lamp lights up
and it does not. Each winding provides a return circuit
to the communtator bar which completes one circuit.
You are checking between each stator windings for open and
or shorts between these windings.
There should be a pattern or shorts and opens around the
communtator. A dc motor has may types of armature winding
methods as each coil lead goes to its own communtator bar,
two cols to the same bar, a coil winding goes to two bars
that is adjacent to each other, a coil winding leads may go
to communtator bars that may be connected up to 180 degrees
apart.
If you find that communtator open close circuit pattern is
the same, then the stator windings may be ok.
3. Take the armature to a motor shop and have them verified your
test. If the armature checks out ok, then you can either have
turn the communator, undercut the segments, re-enamel and provide
you with new brush set and brush springs.
Note: Some brush sets could cost up or over $250.00 if they are
are a double set and are silver-graphite type.
About every ten years, I do this maintenance while the motor is in the EV.
I first remove the brushes and brush springs and clean the communtator and
staror. I then clean out the commutator segments spaces with a under cutter
tool you can purchase from a motor shop or use a hack saw blade that I cut
in half and weld the two pieces together at a 90 degree angle of each other.
Use one of those single hacksaw holders to hold this blade.
As the communtator wear down, you need to lower the insulator between the
bars. I then give the edges of each bar a slight vee cut with a triangle
file which I also had to modified to a 90 degree angle.
Then I spray the communator face and the motor shaft up to the bearing
surfaces with motor enamel that you can get in a spray can from a motor
shop. The reason I spray the communator face and shaft, is to stop the
current tracking to ground which is cause by the brush dust. Using a small
artist brush, I apply the motor enamel on the insulator segments between
each bar.
A motor shop would immerse the stator in motor enamel and bake it. Then
turn the communtor to clean it up. Turning the communtor with a lathe tool
leaves a rough surface which will quickly fill up with the brush material.
This builds up between the communtor segments causing a decrease in
resistance between the bars. This is why I prefer the hard silver-graphite
brushes that are pre-curve and have the communtator micro mirror which means
turning the communtator surface to a mirror finish.
I ran my GE-11 motor with this type of finish and brush type from 1976 to
2006 with no problems doing this maintenance every ten years.
Roland
----- Original Message -----
From: "fred" <[email protected]>
To: "EV DL" <[email protected]>
Sent: Tuesday, January 25, 2011 9:02 AM
Subject: [EVDL] Shunt wound?
> I've had a setback recently in my Gizmo. It crapped out about five miles
> from
> home and had to be ICE-trailered back, but I've found the root cause.
> Broken
> brush wire on one of the brushes, stuck brushes on two others, and I can't
> get
> to number four without pulling the motor.
>
> The commutator looks pretty nasty, all black, but not burned black, so
> maybe it
> needs only a cleaning and trimming. I'm not sure what it's called when the
> bars
> are cut back to a smooth surface, but this one needs it badly. The one
> brush
> that came out is pitted.
>
> I've been in contact with the D&D motor people, as this is an ES-10C sepex
> motor. I was given a price for a rebuilt shunt wound motor. I'm hoping
> that
> means it's a sepex motor. Can someone confirm this?
>
> Is there any reason I would want a new motor (US$535) as opposed to a
> "re-worked" motor (US$380) when it comes to reliability? I certainly do
> not
> abuse my EVs and expect that this is a combination of circumstances, not
> necessarily abuse, but can't rule it out either.
>
> I'm pretty pleased to see a 3-5 day reference on the purchase, much faster
> than
> I expected and faster than I can get a battery pack and monitoring system
> in
> place.
>
> Alternatively, I can ship the motor out west (FL to OR) and have Jim
> Husted work
> his magic on it, but now shipping costs come into consideration, both
> directions.
>
> This is one of those times where I'm willing to pay to get the perceived
> value.
> I don't know what value to put on a re-worked motor, though.
>
> Opinions?
>
>
>
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL:
> http://lists.sjsu.edu/mailman/private/ev/attachments/20110125/ffb24a94/attachment.html
> _______________________________________________
> | REPLYING: address your message to [email protected] only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
>
_______________________________________________
| REPLYING: address your message to [email protected] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
