Recently our oldish KM600 Kenwood mixer started playing up. Strange
noises and even stranger burning smell. Upon investigation discovered a
lot of "carbon" dust distributed around the motor. Motor was sparking a
lot around the area of the carbon brushes. When removing them there were
white scorch marks on the leading edge of the carbon brushes. However,
the brushes otherwise seem to be in good condition and are about 15mm in
length.

One thought is that the carbon brushes are mounted on another material
and it is this material that is now deteriorating. Without seeing brand
new brushes I can't be sure.

It might, of course, be something entirely different causing the
problem. Any ideas anyone?

On Thu, 03 Nov 2005 14:37:08 +0000, Iain Mac Donald
wrote:

Recently our oldish KM600 Kenwood mixer started playing up. Strange
noises and even stranger burning smell. Upon investigation discovered a
lot of "carbon" dust distributed around the motor. Motor was sparking a
lot around the area of the carbon brushes. When removing them there were
white scorch marks on the leading edge of the carbon brushes. However,
the brushes otherwise seem to be in good condition and are about 15mm in
length.

One thought is that the carbon brushes are mounted on another material
and it is this material that is now deteriorating. Without seeing brand
new brushes I can't be sure.

It might, of course, be something entirely different causing the
problem. Any ideas anyone?

A short in one of the windings? Are any of the commutator segnemts
discoloured?

sponix

sPoNiX wrote:


A short in one of the windings?

Once I had taken the vacuum cleaner to the whole thing - covered in old
flour etc. - everything seems to be in order. There is some
discolouration in the area nearest the brushes but this would seem to be
effect rather than cause.

Are any of the commutator segnemts
discoloured?

Yes. The copper (?) coating on one segment is gone but looks more like
cosmetic damage than anything major. Do you think this is significant?

On Thu, 03 Nov 2005 15:00:55 GMT, (sPoNiX) wrote:

| On Thu, 03 Nov 2005 14:37:08 +0000, Iain Mac Donald
| wrote:
|
| Recently our oldish KM600 Kenwood mixer started playing up. Strange
| noises and even stranger burning smell. Upon investigation discovered a
| lot of "carbon" dust distributed around the motor. Motor was sparking a
| lot around the area of the carbon brushes. When removing them there were
| white scorch marks on the leading edge of the carbon brushes. However,
| the brushes otherwise seem to be in good condition and are about 15mm in
| length.
|
| One thought is that the carbon brushes are mounted on another material
| and it is this material that is now deteriorating. Without seeing brand
| new brushes I can't be sure.
|
| It might, of course, be something entirely different causing the
| problem. Any ideas anyone?
|
| A short in one of the windings? Are any of the commutator segnemts
| discoloured?

Raised commentator segment, it happens sometimes.
Spin the com, **by hand** under your finger, that should detect it
--
Dave Fawthrop dave hyphenologist co uk
Help make Usenet a better place: English is read downwards,
please don't top post. Trim replies to quote only relevant text.
Check groups.google.com before asking an obvious question.

Iain Mac Donald wrote:

The copper (?) coating on one segment is gone but looks more like
cosmetic damage than anything major. Do you think this is significant?

The segments should be solid copper - you could try polishing
the commutator with a dry cloth and some meths, and ensuring
the grooves between the segments are clear - don't scratch the
commutator surface, or undercut the segments.

What does the discoloured segment look like?

Chris Bacon wrote:


The segments should be solid copper
Just what I thought - yet underneath it looks more silver/grey!

- you could try polishing
the commutator with a dry cloth and some meths,

Tried that already. No difference.

and ensuring
the grooves between the segments are clear - don't scratch the
commutator surface, or undercut the segments.

What does the discoloured segment look like?

Kind of silver/grey as if the copper layer (?) had been taken off. Only
one segment, neighbours are fine.

Dave Fawthrop wrote:
On Thu, 03 Nov 2005 15:00:55 GMT, (sPoNiX) wrote:

Raised commentator segment, it happens sometimes.
Spin the com, **by hand** under your finger, that should detect it

Can't feel it with my finger (need to get it re-calibrated!) but there
does seem to be a vague click as the damaged segment passes the brush.

Should I ready my junk bin for the imminent arrival of the arm?

On Thu, 03 Nov 2005 15:44:06 +0000, Iain Mac Donald
wrote:

| Dave Fawthrop wrote:
| On Thu, 03 Nov 2005 15:00:55 GMT, (sPoNiX) wrote:
|
| Raised commentator segment, it happens sometimes.
| Spin the com, **by hand** under your finger, that should detect it
|
| Can't feel it with my finger (need to get it re-calibrated!)

No! fingers can detect 1/10,000 inch, so the comm is good enough.
Classic test with jo blocks.

| but there
| does seem to be a vague click as the damaged segment passes the brush.
|
| Should I ready my junk bin for the imminent arrival of the arm?

:-)

--
Dave Fawthrop dave hyphenologist co uk
Help make Usenet a better place: English is read downwards,
please don't top post. Trim replies to quote only relevant text.
Check groups.google.com before asking an obvious question.

Dave Fawthrop wrote:


No! fingers can detect 1/10,000 inch, so the comm is good enough.
Classic test with jo blocks.

Don't have any and my rudimentary micrometer doesn't notice anything.

| but there
| does seem to be a vague click as the damaged segment passes the brush.
|
| Should I ready my junk bin for the imminent arrival of the arm?

:-)

So what is the conclusion? Individual components, except for brushes,
are not available. Only the whole motor (new model including control
unit) is available at £100 plus.

Iain Mac Donald wrote:
So what is the conclusion? Individual components, except for brushes,
are not available. Only the whole motor (new model including control
unit) is available at £100 plus.

http://www.spares2go.co.uk/browse/KE...6904/s4602.htm

£34.32 plus £3.99 p&p

Chris Bacon wrote:
Iain Mac Donald wrote:

So what is the conclusion? Individual components, except for brushes,
are not available. Only the whole motor (new model including control
unit) is available at £100 plus.


http://www.spares2go.co.uk/browse/KE...6904/s4602.htm


£34.32 plus £3.99 p&p

I re-open this to add that e-bay may be a source - Kenwood machines
share parts, see the above URL.

Chris Bacon wrote:
Iain Mac Donald wrote:

So what is the conclusion? Individual components, except for brushes,
are not available. Only the whole motor (new model including control
unit) is available at £100 plus.


http://www.spares2go.co.uk/browse/KE...6904/s4602.htm


£34.32 plus £3.99 p&p

Aha! That is a much better price. Do you know if this is for the early
model KM600 motor (which I have) with grey casing or the later model
with black casing. Maybe the arm fits both models?

Iain Mac Donald wrote:
Chris Bacon wrote:
Iain Mac Donald wrote:
So what is the conclusion? Individual components, except for brushes,
are not available. Only the whole motor (new model including control
unit) is available at £100 plus.

http://www.spares2go.co.uk/browse/KE...6904/s4602.htm

£34.32 plus £3.99 p&p

Aha! That is a much better price. Do you know if this is for the early
model KM600 motor (which I have) with grey casing or the later model
with black casing. Maybe the arm fits both models?

I'm afraid I have no idea - I simple let my fingers Google, in
an idle moment - you could try their "parts enquiry" link on
the LHS of that page....

Chris Bacon wrote:
Iain Mac Donald wrote:

Chris Bacon wrote:

Iain Mac Donald wrote:

So what is the conclusion? Individual components, except for
brushes, are not available. Only the whole motor (new model
including control unit) is available at £100 plus.


http://www.spares2go.co.uk/browse/KE...6904/s4602.htm

£34.32 plus £3.99 p&p


Aha! That is a much better price. Do you know if this is for the early
model KM600 motor (which I have) with grey casing or the later model
with black casing. Maybe the arm fits both models?


I'm afraid I have no idea - I simple let my fingers Google, in
an idle moment - you could try their "parts enquiry" link on
the LHS of that page....

Thanks everyone. Maybe saved a few pennies and learned something along
the way.

Iain Mac Donald wrote:
Chris Bacon wrote:
Iain Mac Donald wrote:

Chris Bacon wrote:

Iain Mac Donald wrote:

So what is the conclusion? Individual components, except for
brushes, are not available. Only the whole motor (new model
including control unit) is available at £100 plus.


http://www.spares2go.co.uk/browse/KE...6904/s4602.htm

£34.32 plus £3.99 p&p


Aha! That is a much better price. Do you know if this is for the early
model KM600 motor (which I have) with grey casing or the later model
with black casing. Maybe the arm fits both models?


I'm afraid I have no idea - I simple let my fingers Google, in
an idle moment - you could try their "parts enquiry" link on
the LHS of that page....

Thanks everyone. Maybe saved a few pennies and learned something along
the way.

You may be looking at the wrong thing here. Had a similar problem with
my sister's Kenwood. It's quite an old heavy duty beast and the top
half swings up. This is where the problem was with hers. Basically the
mains cable needed renewing as it suffered fatigue from the continual
opening and shutting. Worth a look.