W/m (Bosch Exxcel 1200) failed to turn today. I hoped it was just a
failed motor brush but found they were, while well worn, both smooth and
free from cracks etc. In the past with brushes which were simply
getting short I've not had a sudden complete failure but I've seen v
few. Are they still the likely culprit?

Photo in link FWIW.

https://www.dropbox.com/s/224v9656fn...ushes.JPG?dl=0

--
Robin
reply-to address is (intended to be) valid

Robin wrote:

Are they still the likely culprit?

They look considerably worn-down compared to a new set, so I'd think so
(or at least worth a £7 punt).

On 30/08/2020 17:00, Robin wrote:
W/m (Bosch Exxcel 1200) failed to turn today.Â* I hoped it was just a
failed motor brush but found they were, while well worn, both smooth and
free from cracks etc.Â* In the past with brushes which were simply
getting short I've not had a sudden complete failure but I've seen v
few.Â* Are they still the likely culprit?

Photo in link FWIW.

https://www.dropbox.com/s/224v9656fn...ushes.JPG?dl=0



When I had a (Hotpoint) washing machine that had motor brushes the motor
would completely stop when the brushes got too short. On removing the
brushes they would look OK with plenty of the brush left but on
comparison with a new set it became obvious that the old brushes were
around the third of the length of the new brushes. New brushes always
cured my problem with a non-working motor.

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mailto : news {at} admac {dot} myzen {dot} co {dot} uk

Robin wrote:
W/m (Bosch Exxcel 1200) failed to turn today. I hoped it was just a
failed motor brush but found they were, while well worn, both smooth and
free from cracks etc. In the past with brushes which were simply
getting short I've not had a sudden complete failure but I've seen v
few. Are they still the likely culprit?

Photo in link FWIW.

https://www.dropbox.com/s/224v9656fn...ushes.JPG?dl=0


Use your ohmmeter, ohm from end to end (end-of-brush ohms to
connector on other end). Maybe there's a broken wire in there.

Ohms must be low, to allow stall current to flow at 0 RPM.
If the brush contact is ohmic, maybe the end of the brush
becomes glowing hot and it doesn't spin.

Paul

On 30/08/2020 17:00, Robin wrote:
W/m (Bosch Exxcel 1200) failed to turn today.Â* I hoped it was just a
failed motor brush but found they were, while well worn, both smooth and
free from cracks etc.Â* In the past with brushes which were simply
getting short I've not had a sudden complete failure but I've seen v
few.Â* Are they still the likely culprit?

Photo in link FWIW.

https://www.dropbox.com/s/224v9656fn...ushes.JPG?dl=0

Yup I would replace them - they are significantly worn... (should be
about 4cm long on many Bosch wm motors)




--
Cheers,

John.

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Robin Wrote in message:
W/m (Bosch Exxcel 1200) failed to turn today. I hoped it was just a
failed motor brush but found they were, while well worn, both smooth and
free from cracks etc. In the past with brushes which were simply
getting short I've not had a sudden complete failure but I've seen v
few. Are they still the likely culprit?

Photo in link FWIW.

https://www.dropbox.com/s/224v9656fn...ushes.JPG?dl=0

--
Robin
reply-to address is (intended to be) valid


The copper braid is a length that restraints the brush from
reaching the commutator when there is just a fag end
left.

Otherwise the braid and spring would eventually impact the commutator.

--

%Profound_observation%


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On Sunday, 30 August 2020 17:00:17 UTC+1, Robin wrote:
W/m (Bosch Exxcel 1200) failed to turn today. I hoped it was just a
failed motor brush but found they were, while well worn, both smooth and
free from cracks etc. In the past with brushes which were simply
getting short I've not had a sudden complete failure but I've seen v
few. Are they still the likely culprit?

Photo in link FWIW.

https://www.dropbox.com/s/224v9656fn...ushes.JPG?dl=0

Looks like there's approx nothing left of those brushes. Yes I'd replace em.


NT