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Discussion Starter #1
This is the motor out of the other G-Van I recently acquired. It was made
by Nelco in the UK in 1989, and is rated 60hp (45kw) @ 216v and 258 ft. lbs
of torque. It weighs 385lbs!

It is inop, I found out why:
http://ingineerix.com/pic/nelcoboom/

Looks to me like the insulation failed from the shaft to the commutator. I
wonder if this will happen to my current one?

I wonder if it is worth repairing or even possible? Jim?

The one that's running is an amazing beast and accelerates the 7000lb van
quite rapidly. It "redlines" at 6000 rpm which is 55mph. The regen with
the stock controller is amazingly powerful (once I got it working). It will
bring the vehicle to pretty much 0 mph, even downhill (but then it will roll
back).

I'd love to fix it up and put it in a smaller vehicle for some awesome
performance!

-Phil

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Discussion Starter #2
Hi Phil,

Nice pictures of a neat motor. I never saw the inside
of one of these. Biggest face comm I ever saw. Too
bad about the damage. Pic 13 shows part of a threaded
ring about the center of the comm which has a portion
missing. Maybe thrown outward in pieces causing other
damage to parts where the metal shards lodged. Looks
like that threaded ring function was to hold the comm
together. Probably not a standard replacement part.
So, I don't know if you can get it repaired. From
what's left of the ring, a machine shop might be able
to fab one. But, even then, there was probably a mica
insulator ring inside it. Some serious issues.

Brush seating and comm film looks pretty crappy. I
don't think this was a happy motor even before the
failure.

Thanks for the look.

Jeff M



--- "(-Phil-)" <[email protected]> wrote:

> This is the motor out of the other G-Van I recently
> acquired. It was made
> by Nelco in the UK in 1989, and is rated 60hp (45kw)
> @ 216v and 258 ft. lbs
> of torque. It weighs 385lbs!
>
> It is inop, I found out why:
> http://ingineerix.com/pic/nelcoboom/
>
> Looks to me like the insulation failed from the
> shaft to the commutator. I
> wonder if this will happen to my current one?
>
> I wonder if it is worth repairing or even possible?
> Jim?
>
> The one that's running is an amazing beast and
> accelerates the 7000lb van
> quite rapidly. It "redlines" at 6000 rpm which is
> 55mph. The regen with
> the stock controller is amazingly powerful (once I
> got it working). It will
> bring the vehicle to pretty much 0 mph, even
> downhill (but then it will roll
> back).
>
> I'd love to fix it up and put it in a smaller
> vehicle for some awesome
> performance!
>
> -Phil
>

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Discussion Starter #3
There is a "chunk" missing from the ring where is looks like a big arc from
the commutator flashed over and vaporized some of the ring. It's definitely
a very soft metal! It has real fine thread pitch which is screwed onto the
shaft. I tried to use this arc-created divot with a punch to unscrew the
ring to no avail. There is a small glob of molten metal behind the ring
which is probably causing at least one of the shorts. There seems to be
little clearance between the shaft and comm, so it must have been a sleeve
of some sort.

It may be that this armature shaft insulation/sleeve has been somewhat
carbonized and is causing the shorts. I am reading anywhere from 2 ohms to
0 from ALL commutator segments to shaft!

I think the ring itself would be ok, provided I could get it off. I'd have
to liberally apply heat most likely. Maybe combined with a little solvent
of some sort to help loosen the epoxy.

It looks to me like it there was a fiber washer between the ring and comm,
but this was carbonized and came off in loose pieces. Then I think they put
some kind of a mold around the whole area and injected epoxy over the ring
and comm, then machined it down and off the inner ends of the comm bars.

There was a metallic film from plasma on everything. I've found pieces
missing from the aluminum brush holder extrusions, one of the brush
spring/retainer assemblies (stainless?), and the inner ring. I'm sure that
produced a nice film. I was able to sand it off easily with some fine grit
paper.

-Phil
----- Original Message -----
From: "Jeff Major" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Thursday, November 08, 2007 8:51 AM
Subject: Re: [EVDL] 60HP Sepex Motor Destruction


>
> Hi Phil,
>
> Nice pictures of a neat motor. I never saw the inside
> of one of these. Biggest face comm I ever saw. Too
> bad about the damage. Pic 13 shows part of a threaded
> ring about the center of the comm which has a portion
> missing. Maybe thrown outward in pieces causing other
> damage to parts where the metal shards lodged. Looks
> like that threaded ring function was to hold the comm
> together. Probably not a standard replacement part.
> So, I don't know if you can get it repaired. From
> what's left of the ring, a machine shop might be able
> to fab one. But, even then, there was probably a mica
> insulator ring inside it. Some serious issues.
>
> Brush seating and comm film looks pretty crappy. I
> don't think this was a happy motor even before the
> failure.
>
> Thanks for the look.
>
> Jeff M
>
>
>
> --- "(-Phil-)" <[email protected]> wrote:
>
>> This is the motor out of the other G-Van I recently
>> acquired. It was made
>> by Nelco in the UK in 1989, and is rated 60hp (45kw)
>> @ 216v and 258 ft. lbs
>> of torque. It weighs 385lbs!
>>
>> It is inop, I found out why:
>> http://ingineerix.com/pic/nelcoboom/
>>
>> Looks to me like the insulation failed from the
>> shaft to the commutator. I
>> wonder if this will happen to my current one?
>>
>> I wonder if it is worth repairing or even possible?
>> Jim?
>>
>> The one that's running is an amazing beast and
>> accelerates the 7000lb van
>> quite rapidly. It "redlines" at 6000 rpm which is
>> 55mph. The regen with
>> the stock controller is amazingly powerful (once I
>> got it working). It will
>> bring the vehicle to pretty much 0 mph, even
>> downhill (but then it will roll
>> back).
>>
>> I'd love to fix it up and put it in a smaller
>> vehicle for some awesome
>> performance!
>>
>> -Phil
>>
>
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> Do You Yahoo!?
> Tired of spam? Yahoo! Mail has the best spam protection around
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Discussion Starter #4
(-Phil-) wrote:
> There is a "chunk" missing from the ring where is looks like a big arc from
> the commutator flashed over and vaporized some of the ring. It's definitely
> a very soft metal! It has real fine thread pitch which is screwed onto the
> shaft. I tried to use this arc-created divot with a punch to unscrew the
> ring to no avail. There is a small glob of molten metal behind the ring
> which is probably causing at least one of the shorts. There seems to be
> little clearance between the shaft and comm, so it must have been a sleeve
> of some sort.
>
> It may be that this armature shaft insulation/sleeve has been somewhat
> carbonized and is causing the shorts. I am reading anywhere from 2 ohms to
> 0 from ALL commutator segments to shaft!
>
> I think the ring itself would be ok, provided I could get it off. I'd have
> to liberally apply heat most likely. Maybe combined with a little solvent
> of some sort to help loosen the epoxy.
>
> It looks to me like it there was a fiber washer between the ring and comm,
> but this was carbonized and came off in loose pieces. Then I think they put
> some kind of a mold around the whole area and injected epoxy over the ring
> and comm, then machined it down and off the inner ends of the comm bars.
>
> There was a metallic film from plasma on everything. I've found pieces
> missing from the aluminum brush holder extrusions, one of the brush
> spring/retainer assemblies (stainless?), and the inner ring. I'm sure that
> produced a nice film. I was able to sand it off easily with some fine grit
> paper.
>
> -Phil
>

Have you tried passing a current through one of the comm bars to the
shaft? If you could put more than a few amps through it you're probably
up the creek but if you try to put a lot of current through it you might
blow out the short if it is something simple. Now realistically you have
other problems and this wouldn't be a good fix, but interesting to try
perhaps.
-
Martin K



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