DIY Electric Car Forums banner

1 - 4 of 4 Posts

·
Registered
Joined
·
70 Posts
Discussion Starter #1
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
 

·
Registered
Joined
·
70 Posts
Discussion Starter #2
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 --------------
> 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
 

·
Registered
Joined
·
70 Posts
Discussion Starter #3
Hi Fred,
Definition "Shunt" means in "Parallel" it does not mean "Sep-Ex."
"Sep-Ex" is not in parallel or in series, it is "Separately Excited."

In a "Series" the Field and Armature are connected in a end to end
string so all the current goes into one thru it and then into the other and
thru it back to the source (The Controller and batteries.)

In a "Parallel" or "shunt" the ends of the field windings are connected
to the same terminals as the armature brushes, The current is split and some
goes thru the Field and the rest goes thru the Armature via the Brushes.

In a "Sep-Ex" like yours the controller has two controllers inside and sends
different currents to the Field windings than is sent to the Armature by the
other section of the controller. It costs more and the field especially has
more turns of somewhat thinner wire than the Series motor has. However the
performance and efficiency are improved. (And Regen. is a little more easy
to implement. )

I hope the short lecture helps your understanding. IMHO staying with a
"Sep-Ex" (Partially because you have the motor controller for it.) is a much
better choice. Take it to a good shop locally to turn and polish the
commutator and replace the brushes and drive it another 100,000 miles.
Regards,
*Dennis Lee Miles* (Director) *E.V.T.I. inc*.
*www.E-V-T-I-Inc.COM <http://www.e-v-t-i-inc.com/> *(Adviser)*
EVTI-EVAEducation Chapter
*
++++++++++++++++++++++++++++++++
The "Stone Age" didn't end because they ran out of Stones;
It ended because they started using their Brains !
+++++++++++++++++++++++++++++++++++++++++++++

fred <[email protected]> wrote:

> 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
>



--
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.sjsu.edu/mailman/private/ev/attachments/20110125/647c4ea1/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
 

·
Registered
Joined
·
70 Posts
Discussion Starter #4
Fred,

The blower Lee is referring to is the same blower I used in my Gizmo,
however I mounted mine different so it only draws air through a filter
at the back of the cabin. It might be worth working on a cooling
system for your Gizmo while it is down.

Lee Hart <[email protected]> wrote:
> On 1/25/2011 11:02 AM, fred wrote:
>> I've had a setback recently in my Gizmo... 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.
>
> A pizza place near me had a fleet of Gizmos they used for pizza
> delivery. I did some work on them for the owner. He had a substantial
> pile of burned up motors and controllers.
>
> The fundamental problem is that the motor has inadequate cooling, and is
> geared too high. I think they got the reduction as high as they could
> with the sprockets available for a single-stage reduction; but it isn't
> high enough. This forces the motor to run too slow, and draw too much
> current. The low RPM also means the motor's internal fan does not
> provide enough cooling.
>
> We added a marine bilge blower to force air through the motor. The
> controller was also put in a box, both to protect it from water and
> dirt, and also so we could use the same blower to cool it. The air was
> pulled from inside the cabin, across the controller and contactors,
> through the blower, and then through the motor and out.
>
> If it were me, I'd change it to a chain drive to get the ratio higher;
> but the pizza owner didn't want to get that ambitious.
> --
> Lee A. Hart | Ring the bells that still can ring
> 814 8th Ave N | Forget the perfect offering
> Sartell MN 56377 | There is a crack in everything
> leeahart earthlink.net | That's how the light gets in -- Leonard Cohen
>
> _______________________________________________
> | 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
>



-- =

David D. Nelson
http://evalbum.com/1328

_______________________________________________
| 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
 
1 - 4 of 4 Posts
Top