I had a mishap this week when the main terminal on a tractor starter
motor became loose and rotated allowing it to contact the motor winding
terminal, while the engine was running. I didn't notice anything until
the damage was done.

As this is an old ford industrial engine the starter is going to take a
while to arrive so I thought I'd see if the old one could be made
functional again.

The armature seems okay, no shorts to the iron core and the commutator
and brushes are serviceable.

One of the 4 stator coils has shorted and burned off its wrappings, the
others seem fine, the copper is so large a cross section it is not
possible to discriminate the resistance as it is so low but the copper
rectangular section looks sound.

Now looking on you tube if anyone has the time to watch some old school
workmanship:

https://www.youtube.com/watch?v=4bFou5VIFzM

at 2 minutes the guy is cutting some insulation sheet, anyone any idea
what it is and if it is avalable?

Later at 4:20 he wraps with a tape, any ideas what it is and where I can
get some?

At 5:40 a paint is used to cover the wrapped coil, is this likely to be
anything special?

On 01/05/2021 07:13 pm, AJH wrote:

I had a mishap this week whenÂ* the main terminal on a tractor starter
motor became loose and rotated allowing it to contact the motor winding
terminal, while the engine was running. IÂ* didn't notice anything until
the damage was done.

As this is an old ford industrial engine the starter is going to take a
while to arrive so I thought I'd see if the old one could be made
functional again.

The armature seems okay, no shorts to the iron core and the commutator
and brushes are serviceable.

One of the 4 stator coils has shorted and burned off its wrappings, the
others seem fine, the copper is so large a cross sectionÂ* it is not
possible to discriminate the resistance as it is so low but the copper
rectangular section looks sound.

Now looking on you tube if anyone has the time to watch some old school
workmanship:

https://www.youtube.com/watch?v=4bFou5VIFzM

at 2 minutes the guy is cutting some insulation sheet, anyone any idea
what it is and if it is avalable?

Not seen that before (unless, as suggested by another poster, it's PVC).

We used to use Kraft sp? for layered insulation.

For example:

https://www.rajapack.co.uk/protective-packaging/paper-packaging/crepe-kraft-paper-75mmx15m-pack-of-24_skuPCKP.html?priceVAT=true&cq_src=google_ads&cq _cmp=9232197084&cq_con=101859384198&cq_term=&cq_me d=pla&cq_plac=&cq_net=g&cq_pos=&cq_plt=gp&gclid=Cj 0KCQjw-LOEBhDCARIsABrC0TnlShh9oXdT4adQ_Ihtm8l-vm_ppIwztVnvGjqlErZd6V8HO5miMXAaAvOTEALw_wcB&gclsr c=aw.ds

Later at 4:20 he wraps with a tape, any ideas what it is and where I can
get some?

That looks like a woven insulation tape, a bit like this:

https://www.mbfg.co.uk/QL5028.html?gclid=Cj0KCQjw-LOEBhDCARIsABrC0Tkl_UzPAE46ZSVhMtNtyKUOFIEgNg2Mr1x wsk1EiMzvJUwq9QK_H5QaAvOAEALw_wcB

[But completely wrapping stator coils was not common in the armature
winding world.]

At 5:40 a paint is used to cover the wrapped coil, is this likely to be
anything special?

I can see the bright colour, but suggest that that is a varnish rather
than a paint. The purpose (maybe among others) will be to hold the coil
turns firmly and prevent abrasion of the wire's own insulation by
reducing vibration "chatter".

On Sat, 01 May 2021 19:55:31 +0100, GB wrote:

On 01/05/2021 19:13, AJH wrote:
I had a mishap this week whenÂ* the main terminal on a tractor starter
motor became loose and rotated allowing it to contact the motor winding
terminal, while the engine was running. IÂ* didn't notice anything until
the damage was done.

As this is an old ford industrial engine the starter is going to take a
while to arrive so I thought I'd see if the old one could be made
functional again.

The armature seems okay, no shorts to the iron core and the commutator
and brushes are serviceable.

One of the 4 stator coils has shorted and burned off its wrappings, the
others seem fine, the copper is so large a cross sectionÂ* it is not
possible to discriminate the resistance as it is so low but the copper
rectangular section looks sound.

Now looking on you tube if anyone has the time to watch some old school
workmanship:

https://www.youtube.com/watch?v=4bFou5VIFzM

at 2 minutes the guy is cutting some insulation sheet, anyone any idea
what it is and if it is avalable?

How hot does this thing get in normal use? I suspect that the guy in
Pakistan is just using ordinary PVC sheeting. However, as we don't know
for sure, why not use some oven liner?

https://www.johnlewis.com/nostik-tef...g-mat/p2925542



Later at 4:20 he wraps with a tape, any ideas what it is and where I
can get some?

Sellotape?


However, to avoid potential problems use high temperature tape:

https://www.amazon.co.uk/TOOHUI-Temp...ant-25mmx10mm/
dp/B07MNRJC9S




At 5:40 a paint is used to cover the wrapped coil, is this likely to be
anything special?



Lots of high temperature paints available.



I gather you have a new starter on order, so this is a temporary stop
gap solution. I'm not sure what the downside is if it fails? Will it
bork the engine, or just put you back to square one?

If the downside risk is small, I'd just use ordinary plastic insulator
and ordinary tape and paint. If you want to be sure it's a good repair,
then spend 20 quid on high temp bits to fix it.

And whichever route you go, you NEED to spend another 20 quid on PPE
before you burn the existing insulation off. Life is cheap on the
sub-continent.

Or even PTFE tape.

On 01/05/2021 19:13, AJH wrote:
I had a mishap this week whenÂ* the main terminal on a tractor starter
motor became loose and rotated allowing it to contact the motor winding
terminal, while the engine was running. IÂ* didn't notice anything until
the damage was done.

As this is an old ford industrial engine the starter is going to take a
while to arrive so I thought I'd see if the old one could be made
functional again.

The armature seems okay, no shorts to the iron core and the commutator
and brushes are serviceable.

One of the 4 stator coils has shorted and burned off its wrappings, the
others seem fine, the copper is so large a cross sectionÂ* it is not
possible to discriminate the resistance as it is so low but the copper
rectangular section looks sound.

Now looking on you tube if anyone has the time to watch some old school
workmanship:

https://www.youtube.com/watch?v=4bFou5VIFzM

at 2 minutes the guy is cutting some insulation sheet, anyone any idea
what it is and if it is avalable?

'insulation sheet'; on old kit would be something like phenolic resin
impregnated paper - a sort of bakelite lookalike - but that looks
alarmingly like simple plastic sheet. Which will melt at high temperatures.

You can buy stuff like that at any model shop.
Oh thinking, I'd use ptfe.

https://www.ebay.co.uk/itm/223216541194

Later at 4:20 he wraps with a tape, any ideas what it is and where I can
get some?

Almost anything would do. Back in the day it might have been cotton or
linen.

I wouldn't use nylon - cotton 'webbing tape' is probably best these days.

https://www.ebay.co.uk/itm/191918411510


At 5:40 a paint is used to cover the wrapped coil, is this likely to be
anything special?


Typically old electric wire was insulated with shellac. French polish to
you.

That looks like 'any old muck'. Its only there to stabilise the tape.

For the authentic Awful Smell on overload, why not use shellac?




--
"Socialist governments traditionally do make a financial mess. They
always run out of other people's money. It's quite a characteristic of them"

Margaret Thatcher

Well some coil rewiinders tend to pot the winding if there is room to
achieve this, it often last longer than the traditional vanish approach.
Brian

--

This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
"AJH" wrote in message
...
I had a mishap this week when the main terminal on a tractor starter motor
became loose and rotated allowing it to contact the motor winding terminal,
while the engine was running. I didn't notice anything until the damage
was done.

As this is an old ford industrial engine the starter is going to take a
while to arrive so I thought I'd see if the old one could be made
functional again.

The armature seems okay, no shorts to the iron core and the commutator and
brushes are serviceable.

One of the 4 stator coils has shorted and burned off its wrappings, the
others seem fine, the copper is so large a cross section it is not
possible to discriminate the resistance as it is so low but the copper
rectangular section looks sound.

Now looking on you tube if anyone has the time to watch some old school
workmanship:

https://www.youtube.com/watch?v=4bFou5VIFzM

at 2 minutes the guy is cutting some insulation sheet, anyone any idea
what it is and if it is avalable?

Later at 4:20 he wraps with a tape, any ideas what it is and where I can
get some?

At 5:40 a paint is used to cover the wrapped coil, is this likely to be
anything special?

We used to use Mica, but the bend radius needs to be quite obtuse. There is
also mylar film that is often used in a tape form, its often yellow, what
colour is it in the video?
Brian

--

This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
"jon" wrote in message ...
On Sat, 01 May 2021 19:55:31 +0100, GB wrote:

On 01/05/2021 19:13, AJH wrote:
I had a mishap this week when the main terminal on a tractor starter
motor became loose and rotated allowing it to contact the motor winding
terminal, while the engine was running. I didn't notice anything until
the damage was done.

As this is an old ford industrial engine the starter is going to take a
while to arrive so I thought I'd see if the old one could be made
functional again.

The armature seems okay, no shorts to the iron core and the commutator
and brushes are serviceable.

One of the 4 stator coils has shorted and burned off its wrappings, the
others seem fine, the copper is so large a cross section it is not
possible to discriminate the resistance as it is so low but the copper
rectangular section looks sound.

Now looking on you tube if anyone has the time to watch some old school
workmanship:

https://www.youtube.com/watch?v=4bFou5VIFzM

at 2 minutes the guy is cutting some insulation sheet, anyone any idea
what it is and if it is avalable?

How hot does this thing get in normal use? I suspect that the guy in
Pakistan is just using ordinary PVC sheeting. However, as we don't know
for sure, why not use some oven liner?

https://www.johnlewis.com/nostik-tef...g-mat/p2925542



Later at 4:20 he wraps with a tape, any ideas what it is and where I
can get some?

Sellotape?


However, to avoid potential problems use high temperature tape:

https://www.amazon.co.uk/TOOHUI-Temp...ant-25mmx10mm/
dp/B07MNRJC9S




At 5:40 a paint is used to cover the wrapped coil, is this likely to be
anything special?



Lots of high temperature paints available.



I gather you have a new starter on order, so this is a temporary stop
gap solution. I'm not sure what the downside is if it fails? Will it
bork the engine, or just put you back to square one?

If the downside risk is small, I'd just use ordinary plastic insulator
and ordinary tape and paint. If you want to be sure it's a good repair,
then spend 20 quid on high temp bits to fix it.

And whichever route you go, you NEED to spend another 20 quid on PPE
before you burn the existing insulation off. Life is cheap on the
sub-continent.

Or even PTFE tape.

"Brian Gaff \(Sofa\)" wrote:
Well some coil rewiinders tend to pot the winding if there is room to
achieve this, it often last longer than the traditional vanish approach.

Nice one! :-)

--
Chris Green
·

On 01/05/2021 19:13, AJH wrote:
I had a mishap this week whenÂ* the main terminal on a tractor starter
motor became loose and rotated allowing it to contact the motor winding
terminal, while the engine was running. IÂ* didn't notice anything until
the damage was done.

As this is an old ford industrial engine the starter is going to take a
while to arrive so I thought I'd see if the old one could be made
functional again.

The armature seems okay, no shorts to the iron core and the commutator
and brushes are serviceable.

One of the 4 stator coils has shorted and burned off its wrappings, the
others seem fine, the copper is so large a cross sectionÂ* it is not
possible to discriminate the resistance as it is so low but the copper
rectangular section looks sound.

Now looking on you tube if anyone has the time to watch some old school
workmanship:

https://www.youtube.com/watch?v=4bFou5VIFzM

at 2 minutes the guy is cutting some insulation sheet, anyone any idea
what it is and if it is avalable?

The sound it makes while being is the same as some very thin phenolic
resin sheet I used to have, but that was brown.

Later at 4:20 he wraps with a tape, any ideas what it is and where I can
get some?

It looks like asbestos tape and if that is being done in Pakistan, it
might be. However, there is a wide range of safer alternatives;

https://www.bevi.com/products/coil-w...s-non-adhesive

At 5:40 a paint is used to cover the wrapped coil, is this likely to be
anything special?

As others have said, that looks more like a varnish than a paint. The
same web site offers these:

https://www.bevi.com/products/coil-w...on-and-casting


--
Colin Bignell

On 02/05/2021 09:10, jon wrote:
On Sat, 01 May 2021 19:55:31 +0100, GB wrote:


How hot does this thing get in normal use? I suspect that the guy in
Pakistan is just using ordinary PVC sheeting. However, as we don't know
for sure, why not use some oven liner?

https://www.johnlewis.com/nostik-tef...g-mat/p2925542

Well it gets pretty warm as it is 50mm from the exhaust manifold and it
looks like the nearest one to that is the one that failed however
I'mloathe to use what has not been used for this before and am
surprised not to find someone who has done this in the past here.


However, to avoid potential problems use high temperature tape:

https://www.amazon.co.uk/TOOHUI-Temp...ant-25mmx10mm/
dp/B07MNRJC9S


That looks suitable though what's on there on the remaining coils looks
like a cotton cloth tape.


I gather you have a new starter on order, so this is a temporary stop
gap solution. I'm not sure what the downside is if it fails? Will it
bork the engine, or just put you back to square one?

Yes on order but no acknowledgement on when it might arrive and the
machine is stuck in a wood, I may have to take another tractor to drag
it out and then bump start it. If I can fix this before the other
arrives it needs to be good enough to last as it's an awkward job to fit
in a tight space.

And whichever route you go, you NEED to spend another 20 quid on PPE
before you burn the existing insulation off. Life is cheap on the
sub-continent.

No need to burn anything off the shorting out did that.

Or even PTFE tape.

As in plumber's tape, I'd think it not strong enough.

On 02/05/2021 09:16, The Natural Philosopher wrote:

You can buy stuff like that at any model shop.
Oh thinking, I'd use ptfe.

https://www.ebay.co.uk/itm/223216541194

Thanks I wonder how that differs from the oven liner.

I wouldn't use nylon - cotton 'webbing tape' is probably best these days.

https://www.ebay.co.uk/itm/191918411510


Yes looks about right

For the authentic Awful Smell on overload, why not use shellac?
I wondered what that smell was.

On 02/05/2021 10:42, nightjar wrote:

It looks like asbestos tape and if that is being done in Pakistan, it
might be. However, there is a wide range of safer alternatives;

https://www.bevi.com/products/coil-w...s-non-adhesive

At 5:40 a paint is used to cover the wrapped coil, is this likely to
be anything special?

As others have said, that looks more like a varnish than a paint. The
same web site offers these:

https://www.bevi.com/products/coil-w...on-and-casting




Good find but one page says sold only in the Swedish market.

On 02/05/2021 11:19, AJH wrote:
On 02/05/2021 10:42, nightjar wrote:

It looks like asbestos tape and if that is being done in Pakistan, it
might be. However, there is a wide range of safer alternatives;

https://www.bevi.com/products/coil-w...s-non-adhesive

At 5:40 a paint is used to cover the wrapped coil, is this likely to
be anything special?

As others have said, that looks more like a varnish than a paint. The
same web site offers these:

https://www.bevi.com/products/coil-w...on-and-casting




Good find but one page says sold only in the Swedish market.

I didn't see that, but it was the first hit I got on a Google search for
motor rewinding supplies. There are plenty of motor rewinders in the UK
and they must get their supplies from somewhere.

--
Colin Bignell

On 02/05/2021 12:14, nightjar wrote:


I didn't see that, but it was the first hit I got on a Google search for
motor rewinding supplies. There are plenty of motor rewinders in the UK
and they must get their supplies from somewhere.


Thanks for taking the trouble to look. In the meanwhile I have ordered a
sheet of 0.5mm PTFE, the adhesive PTFE covered fibre glass tape and some
exhaust paint. The PTFE won't be here till June and I hope the new motor
will be fitted by then, so I will do a repair at my leisure.

On 02/05/2021 13:19, AJH wrote:
On 02/05/2021 12:14, nightjar wrote:


I didn't see that, but it was the first hit I got on a Google search
for motor rewinding supplies. There are plenty of motor rewinders in
the UK and they must get their supplies from somewhere.


Thanks for taking the trouble to look. In the meanwhile I have ordered a
sheet of 0.5mm PTFE, the adhesive PTFE covered fibre glass tape and some
exhaust paint. The PTFE won't be here till June and I hope the new motor
will be fitted by then, so I will do a repair at my leisure.

Full marks for considering a fairly out of the normal repair. That's one
job I have never done myself (although having seen from YouTube how it
is done, I realise it is not quite so daunting as it appeared when I was
a cash-strapped youth).