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check the carbon brushes in the wiper-motor


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This topic has been prompted by wiper-brush kits becoming available on eBay for much lower prices than hitherto,  £12 as against £25 or more.

And I bought a DR2 from 1958 with the classic destroyed commutator, caused by running with worn-out brushes.

A few years back I'd have to store a motor like this until a new armature turned up.  Both DR2 and DR3A wiper-motors will run to destruction without carbon-brushes.  This one was running OK, if a bit squeaky.

Then I bought some commutators from the US and could fix them.  But after shipping, import cost and VAT these worked out to cost around £10 each.

Now I can get them on eBay from China for less than £3 including shipping.  And very good parts they are too.

The photos are largely self-explanatory I think.  Except photo 3.  I get the old commutator off by crushing in a vise. You can see that only a few thou of copper remains and if run a little longer this would all come apart.

More or less anybody with a soldering iron could do this job and it would take only an hour or so.

The last photo shows the front area of shaft where the bearing runs.  Even after 60 years of hard life I cannot measure any wear here.  They are usually like this.  Whereas NOS ones in boxes are often rusty, even if advertised at £100 or more.

kibach-1.jpg

kibach-2.jpg

kibach-3.jpg

kibach-4.jpg

kibach-5.jpg

kibach-6.jpg

kibach-7.jpg

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Thanks for that John.

Sometimes you get 70-80 views and nobody says anything and then you wonder if you did right!

The heater-fan motors are much the same I believe.

These commutators are close but not exactly the same.  The important thing is to have the same number of segments, which is 10.

Next is size of the hole for the shaft,   The ones I've been getting are just a bit tight.  You will split them if you force them on.  A little easing with a round file is all that is needed and then some Loctite.

Note a DR2  has bigger shaft than a DR3A. So I've got two sizes to worry about.

The outside diameter and the length don't matter too much. But you need to be careful the brushes don't hit the tags or fall off the end, basic stuff really.

Note the position of the tag compared to the winding.  This is not extremely critical and I just copy the factory ones by eye, but do pay attention to this because it affects commutation a bit and you might get sparking.

For just a few quid and little time you can get home in the rain without a drama.

Edited by AlanT
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Hi Alan,

your write ups are highly appreciated by me, it makes jobs otherwise perceived impossible worth a go.

Many thanks,

Waldi

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Thanks for the reply, Waldi.

To encourage anyone reading this it's quite easy to completely rewind one of these armatures.  I do it quite often.

They get burned out if the motor gets stalled. Common in the old days with ice on the screen.

It's tedious but not very much skill required.  Like much of this work the secret is attention to detail.

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28 minutes ago, AlanT said:

Thanks for the reply, Waldi.

To encourage anyone reading this it's quite easy to completely rewind one of these armatures.  I do it quite often.

They get burned out if the motor gets stalled. Common in the old days with ice on the screen.

It's tedious but not very much skill required.  Like much of this work the secret is attention to detail.

Back in the 60`s we used to hand rewind slot-car electric motor armatures to make them go faster!

Stuart.

Edited by stuart
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53 minutes ago, AlanT said:

Thanks for the reply, Waldi.

To encourage anyone reading this it's quite easy to completely rewind one of these armatures.  I do it quite often.

They get burned out if the motor gets stalled. Common in the old days with ice on the screen.

It's tedious but not very much skill required.  Like much of this work the secret is attention to detail.

Do you varnish and bake the windings after rewind to retain then from flinging out when run.   or are the armatures too slow in rotation to warrant it?

Peter W

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1 hour ago, stuart said:

Back in the 60`s we used to hand rewind slot-car electric motor armatures to make them go faster!

Stuart.

I did a lot of that! My local slot car club couldn't cope with my motors drawing 40A!

Pete

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I impregnate them with Ultimeg 2000.

Actually the wires won't fly out even if I didn't do this.  As each winding finishes the wire passes to the next slot. Then another winding goes on top locking the end in place.  Only the last two coils might escape.  But they get trapped by the start end of the first winding appearing from the depths.

Winding by hand I get a somewhat more even and tight packing than the machine did.  The factory windings are a bit random.

DL2-2.jpg

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16 hours ago, stillp said:

I did a lot of that! My local slot car club couldn't cope with my motors drawing 40A!

Pete

Hand controllers used to get really hot too!

Stuart.

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3 hours ago, iain said:

Really useful stuff Alan, not sure its something I would tackle, but great to know how!

Iain

Worth an article in TRaction!

But that is easy said, if you do not have to write that yourselves.

Waldi

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43 minutes ago, Lebro said:

I thought he had !

Bob.

If so I apologise and I must have had a senior moment....

Regards,

Waldi

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Alan T said:

“And for a Maserati Quatroporte .”

I bought one of those once in 1973.

It was a 1960’s something…

 

I bought it from a Tax Free dealer in Athens for  $US 1000.

You could buy all sorts of “Dodgy” exotica from the tax-free dealers for next to nothing back then. The pedals and the steering wheel were wired together with lead seals on them, because you were not allowed to drive them on the road until you had bought them. The dealers always found a way to slip the wires off them though, so you could take them around the block as a test drive.

 

The wiper motor was the least of the problems.

 

It only did 4 Miles Per Gallon in the city and 6 MPG on the open road.

I always felt that if I broke the windscreen it would cost a year’s wages to replace it.

I remember putting my foot down and suddenly finding I was doing 120 MPH.

 

Sold it soon afterwards.

 

Charlie.

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