I noticed that our central vac didn't sound right today. I took the plastic
housing off the top of the motor so the commutator and brushes were visible
and started it up. After a few seconds of operation I start to see the blue
spark between the brushes and commutator start to extend almost 1/2" in the
direction of rotation around the commutator. As this happens the speed of
the motor slowly begins to drop. The motor was overhauled last April; new
bearings and brushes.The vacuum is 22 yrs old so the commutator on the motor
has seen a lot of wear but it looks in reasonable shape. Anybody have an
idea what might be happening here?
Thanks,
Mike
--

Remove -NOSPAM- to email please.

wrote:

I noticed that our central vac didn't sound right today. I took the
plastic housing off the top of the motor so the commutator and brushes
were visible and started it up. After a few seconds of operation I start
to see the blue spark between the brushes and commutator start to extend
almost 1/2" in the direction of rotation around the commutator. As this
happens the speed of the motor slowly begins to drop. The motor was
overhauled last April; new bearings and brushes.The vacuum is 22 yrs old
so the commutator on the motor has seen a lot of wear but it looks in
reasonable shape. Anybody have an idea what might be happening here?
Thanks,
Mike

You might need to clean out the slots on the commutator
Also, make sure the brushes are the correct ones and have proper tension.
Eric

On Jan 26, 8:44 pm, wrote:
I noticed that our central vac didn't sound right today. I took the plastic
housing off the top of the motor so the commutator and brushes were visible
and started it up. After a few seconds of operation I start to see the blue
spark between the brushes and commutator start to extend almost 1/2" in the
direction of rotation around the commutator. As this happens the speed of
the motor slowly begins to drop. The motor was overhauled last April; new
bearings and brushes.The vacuum is 22 yrs old so the commutator on the motor
has seen a lot of wear but it looks in reasonable shape. Anybody have an
idea what might be happening here?

Adding to Eric's commen\ts, the overhaul should also have included
truing and smoothing the commutator. My bet is on wrong brush type for
the unit. Central vacs are robust machines that can draw considerable
current and require a high conductivity brush and maximum commutator
contact. The proper brush may even need considerable copper content
like those in auto starter motors. A set of OEM brushes might help the
problem. HTH

Joe

Sounds like the brush springs are weak.

--
Steve Barker


wrote in message
...
I noticed that our central vac didn't sound right today. I took the plastic
housing off the top of the motor so the commutator and brushes were visible
and started it up. After a few seconds of operation I start to see the blue
spark between the brushes and commutator start to extend almost 1/2" in the
direction of rotation around the commutator. As this happens the speed of
the motor slowly begins to drop. The motor was overhauled last April; new
bearings and brushes.The vacuum is 22 yrs old so the commutator on the
motor has seen a lot of wear but it looks in reasonable shape. Anybody have
an idea what might be happening here?
Thanks,
Mike
--

Remove -NOSPAM- to email please.

On Fri, 26 Jan 2007 18:59:27 -0800, Eric wrote:

wrote:

I noticed that our central vac didn't sound right today. I took the
plastic housing off the top of the motor so the commutator and brushes
were visible and started it up. After a few seconds of operation I start
to see the blue spark between the brushes and commutator start to extend
almost 1/2" in the direction of rotation around the commutator. As this
happens the speed of the motor slowly begins to drop. The motor was
overhauled last April; new bearings and brushes.The vacuum is 22 yrs old
so the commutator on the motor has seen a lot of wear but it looks in
reasonable shape. Anybody have an idea what might be happening here?
Thanks,
Mike

You might need to clean out the slots on the commutator

They used to say to "undercut the mica". Does that still apply? Did
the overhauler do that last April? The mica is the stuff between the
copper segments. When the copper wears down, the mica has to be cut
down, I guess.

Also, make sure the brushes are the correct ones and have proper tension.
Eric

wrote in message
...
I noticed that our central vac didn't sound right today. I took the plastic
housing off the top of the motor so the commutator and brushes were visible
and started it up. After a few seconds of operation I start to see the blue
spark between the brushes and commutator start to extend almost 1/2" in the
direction of rotation around the commutator. As this happens the speed of
the motor slowly begins to drop. The motor was overhauled last April; new
bearings and brushes.The vacuum is 22 yrs old so the commutator on the
motor has seen a lot of wear but it looks in reasonable shape. Anybody have
an idea what might be happening here?
Thanks,
Mike
--

Remove -NOSPAM- to email please.
22 years old? Buy a new vacuum cleaner.

"Gerald Newton" wrote in message
...

wrote in message
...
I noticed that our central vac didn't sound right today. Mike
--

..
22 years old? Buy a new vacuum cleaner.

It's a central vac, not a $69 special. No reason not to fix it.

On Jan 27, 8:37 am, "Edwin Pawlowski" wrote:
"Gerald Newton" wrote in messagenews:B_WdnVNYidbYaCfYnZ2dnUVZ_vvinZ2d@gigan ews.com...



wrote in message
...
I noticed that our central vac didn't sound right today. Mike
--

.
22 years old? Buy a new vacuum cleaner.It's a central vac, not a $69 special. No reason not to fix it.


Well, maybe there is a reason to replace it. He already spent time
and money having the motor rebuilt less than a year ago. I guess I'd
first take it back to whoever rebuilt the motor and ask them what's
wrong. If I didn't get a convincing explanation, or it was going to
cost much more to fix again, I'd be looking at a new one. You can
get one for $250+

wrote:

I noticed that our central vac didn't sound right today. I took the plastic
housing off the top of the motor so the commutator and brushes were visible
and started it up. After a few seconds of operation I start to see the blue
spark between the brushes and commutator start to extend almost 1/2" in the
direction of rotation around the commutator. As this happens the speed of
the motor slowly begins to drop. The motor was overhauled last April; new
bearings and brushes.The vacuum is 22 yrs old so the commutator on the motor
has seen a lot of wear but it looks in reasonable shape. Anybody have an
idea what might be happening here?
Thanks,
Mike

It sounds to me like whoever did the overhaul used the wrong brushes.
They're probably shedding carbon.

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form .

wrote:


On Jan 27, 8:37 am, "Edwin Pawlowski" wrote:

"Gerald Newton" wrote in messagenews:B_WdnVNYidbYaCfYnZ2dnUVZ_vvinZ2d@gigan ews.com...




wrote in message
...

I noticed that our central vac didn't sound right today. Mike
--


.

22 years old? Buy a new vacuum cleaner.It's a central vac, not a $69 special. No reason not to fix it.



Well, maybe there is a reason to replace it. He already spent time
and money having the motor rebuilt less than a year ago. I guess I'd
first take it back to whoever rebuilt the motor and ask them what's
wrong. If I didn't get a convincing explanation, or it was going to
cost much more to fix again, I'd be looking at a new one.

"One?" If that means a new re-builder, I guess I'd agree.

You can
get one for $250+



--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form .

Thanks to all who responded to my original post. I've taken a good look at
the commutator on the motor and it doesn't look in the best of shape. I
think the heat and arcing has pitted it badly. Guess I will look at
replacing the motor. Apparently a replacement Lamb motor runs $195 to $245
here in Canada.
Thanks,
Mike

wrote in message
...
I noticed that our central vac didn't sound right today. I took the plastic
housing off the top of the motor so the commutator and brushes were visible
and started it up. After a few seconds of operation I start to see the blue
spark between the brushes and commutator start to extend almost 1/2" in the
direction of rotation around the commutator. As this happens the speed of
the motor slowly begins to drop. The motor was overhauled last April; new
bearings and brushes.The vacuum is 22 yrs old so the commutator on the
motor has seen a lot of wear but it looks in reasonable shape. Anybody have
an idea what might be happening here?
Thanks,
Mike
--

Remove -NOSPAM- to email please.

Well I took the central vac into the dealer this morning so he could make
sure I was getting the correct replacement motor. Of course he wanted to try
it, to see what was wrong. After seeing it run for 15 secs he stopped it ,
went to the back of his shop and came back with a gray stick of some type of
abrasive material. He started up the vacuum, held the stick in some needle
nose pliers and ran it up and down the commutator a few times, removed the
stick and let the vacuum run. The severe arcing had disappeared and he
pronounced it good for another 5 years! He said this stick was the best
thing for removing any carbon buildup between the commutator and also for
removing any rough spots. It was about $10 CDN per stick. Sorry but I've
forgotten the name ot it already ( CRS disease). Of course while there my
wife spotted the new type of electrified hose with on/off switch on the
handle and wanted one, ( doesn't like my duct tape repair on the old one )
so the guy was happy to not charge for the work and we came away with a
little extra on our Visa bill!
Mike
--

Remove -NOSPAM- to email please.

wrote in message
...
Thanks to all who responded to my original post. I've taken a good look at
the commutator on the motor and it doesn't look in the best of shape. I
think the heat and arcing has pitted it badly. Guess I will look at
replacing the motor. Apparently a replacement Lamb motor runs $195 to $245
here in Canada.
Thanks,
Mike

wrote in message
...
I noticed that our central vac didn't sound right today. I took the
plastic housing off the top of the motor so the commutator and brushes
were visible and started it up. After a few seconds of operation I start
to see the blue spark between the brushes and commutator start to extend
almost 1/2" in the direction of rotation around the commutator. As this
happens the speed of the motor slowly begins to drop. The motor was
overhauled last April; new bearings and brushes.The vacuum is 22 yrs old
so the commutator on the motor has seen a lot of wear but it looks in
reasonable shape. Anybody have an idea what might be happening here?
Thanks,
Mike
--

Remove -NOSPAM- to email please.

Well I took the central vac into the dealer this morning so he could make
sure I was getting the correct replacement motor. Of course he wanted to try
it, to see what was wrong. After seeing it run for 15 secs he stopped it ,
went to the back of his shop and came back with a gray stick of some type of
abrasive material. He started up the vacuum, held the stick in some needle
nose pliers and ran it up and down the commutator a few times, removed the
stick and let the vacuum run. The severe arcing had disappeared and he
pronounced it good for another 5 years! He said this stick was the best
thing for removing any carbon buildup between the commutator and also for
removing any rough spots. It was about $10 CDN per stick. Sorry but I've
forgotten the name ot it already ( CRS disease). Of course while there my
wife spotted the new type of electrified hose with on/off switch on the
handle and wanted one, ( doesn't like my duct tape repair on the old one )
so the guy was happy to not charge for the work and we came away with a
little extra on our Visa bill!

Mike
--

Remove -NOSPAM- to email please.



wrote in message
...
Thanks to all who responded to my original post. I've taken a good look at
the commutator on the motor and it doesn't look in the best of shape. I
think the heat and arcing has pitted it badly. Guess I will look at
replacing the motor. Apparently a replacement Lamb motor runs $195 to $245
here in Canada.
Thanks,
Mike

wrote in message
...
I noticed that our central vac didn't sound right today. I took the
plastic housing off the top of the motor so the commutator and brushes
were visible and started it up. After a few seconds of operation I start
to see the blue spark between the brushes and commutator start to extend
almost 1/2" in the direction of rotation around the commutator. As this
happens the speed of the motor slowly begins to drop. The motor was
overhauled last April; new bearings and brushes.The vacuum is 22 yrs old
so the commutator on the motor has seen a lot of wear but it looks in
reasonable shape. Anybody have an idea what might be happening here?
Thanks,
Mike
--

Remove -NOSPAM- to email please.