D. Colo on sat 24 may 03
I looked through the archives but did not find answers
on these questions.
I have an old Brent C which is making quite a bit of
noise and vibrating, especially at high speeds (with
no clay on it). It's not squeaking or whining, more
of a loud hum but no grinding sound. There's no
visible problem (to me, at least) with the mounting of
the motor or the flywheel/belt other than the belt is
very slightly frayed.
I did call Brent and spoke with someone about
repairing it. From what I've been told (or read in
the clayart archives), it could be the brushes are
dirty and need replacing or the bearings are shot and
the motor itself needs to be replaced (or rebuilt, but
it's pretty old already).
The best rough estimate I could get (from someone
local who repairs pottery wheels) on replacing the
motor is somewhere around $350 including labor,
depending on what actually needs to be done. I have
no idea what it would cost to simply replace the
brushes if that's all it needs, but obviously, it
would be considerably less (maybe $150??? at my own
guess...).
I've been told by someone who knows nothing about
pottery wheels (but *IS* good with cars, lawn mowers,
etc.) that the motor could be replaced with basically
any 1/2 HP motor such as Sears sells and that he could
easily do the replacement for me. Is that realistic?
While I appreciate his offer, I have no idea whether
someone who isn't familiar with pottery wheels could
do this. (He, of course, is firmly convinced that he
can fix anything mechanical and isn't likely to admit
it if the wheel repair really requires expert
knowledge.) Would he really need to know the
intricacies of a pottery wheel to do a good job?
Would any 1/2 HP motor really work or would it *not*
be a good idea to try that? I guess I could always
order a Brent motor if necessary, instead of going
with the no doubt less expensive Sears version.
Any suggestions on this would be much appreciated.
Thanks!
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Vince Pitelka on sun 25 may 03
> First, you need to find out for sure if the problem is in the motor.
> Take the belt off the motor and run it. Is the loud hum and vibration
> still there?
> If not, it is the belt or the wheelhead bearings.
David -
You give great advice, but this is a little more complicated. A motor with
bad bearings will often run very smoothly under no load, especially if it is
mounted vertically. We had that happen with our Venco pugmill. Without a
load, in the electric motor shop, the motor ran smooth as can be. Under
load, the armature was actually scraping against the field magnets. In this
case, if the motor is going bad, it may specifically be the side thrust of
the belt tension that is causing it to misbehave.
For the person who posted the original message, I think the best diagnosis
in this case requires a stethoscope, or in lieu of that, a piece of 1/2"
wood dowel. With the wheel running under load, press the dowel against the
base of the motor, and the other end against the outer flap of your ear
opening. Try it at the base of the wheelhead flange. You should be able to
hear the offending parts very clearly, allowing you to isolate the problem
to the motor or the wheelhead bearings.
If the noise does not seem to originate primarily from either of those
locations, the problem is probably in the belt, and it should show up when
you remove the belt and examine it. A belt that causes excessive noise
and/or vibration is usually work-hardened and checked or cracked. That
should be obvious under close examination. The belt should bend backwards
without any cracks or checks showing up on the inner surface.
Best wishes -
- Vince
Vince Pitelka
Appalachian Center for Craft
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Home - vpitelka@dtccom.net
615/597-5376
Office - wpitelka@tntech.edu
615/597-6801 x111, FAX 615/597-6803
http://iweb.tntech.edu/wpitelka/
John Rodgers on sun 25 may 03
David, I have a Brent CXC which has a 1 horsepower DC motor with
electronic controller. A check on Graingers Web Site reveals that a 1
horse, 90 volt DC motor, 1750 rpm, with electronic controller will cost
about $800. Without the controller about $500. Depends just a bit on
the brand. The price goes down as horsepower drops. I used a Creative
Industries wheel for a while that had a 1/4 HP motor and it performed
beautifully, but you could slow it by loading it heavily or working
fairly dry clay on it. So low HP motors can work. And the cost can be
lower, but I suspect that the life of such a motor will be shorter.
Regards,
John Rodgers
Birmingham, AL
David Hendley wrote:
>First, you need to find out for sure if the problem is in the motor.
>Take the belt off the motor and run it. Is the loud hum and vibration
>still there?
>If not, it is the belt or the wheelhead bearings.
>If so, it could be the motor or the controller. Take the motor to an
>auto alternator/starter shop and ask them to test it.
>If the motor tests OK, you need a new control box and/or pedal , which
>will only be available from Brent.
>
>Motor brushes do not "get dirty", but they wear out (wear down to
>nothing, like a brake shoe). To check them, or replace them, you
>simply remove the 2 large screws on the body of the motor.
>There should be at least half an inch of black carbon material, curved
>to fit the motor armature on one end, and attached to a wire and spring
>on the other end.
>New brushes should cost on the order of $20 from a motor supply place
>like W. W. Grainger.
>
>It is not too hard to replace worn out motor bearings. They will be about
>$30. I sent in step-by-step instructions for doing this to Clayart a few
>years ago, under the heading "The day the crickets died".
>If you need new brushes or bearings, take the old ones with you to the
>store, to make sure you get the right replacements.
>
>Pottery wheel motors are DC (direct current), not the more common
>AC (alternating current). Sears does not stock such motors, but
>a place like Grainger's does.
>I'm not sure I've kept up with prices, but it should be under $200 for a
>new one. Again, take your old motor, to show them what you want.
>
>David Hendley
>Maydelle, Texas
>david@farmpots.com
>http://www.farmpots.com
>
>
>----- Original Message -----
>
>
>>I have an old Brent C which is making quite a bit of
>>noise and vibrating, especially at high speeds (with
>>no clay on it). It's not squeaking or whining, more
>>of a loud hum but no grinding sound. There's no
>>visible problem (to me, at least) with the mounting of
>>the motor or the flywheel/belt other than the belt is
>>very slightly frayed.
>>
>>I did call Brent and spoke with someone about
>>repairing it. From what I've been told (or read in
>>the clayart archives), it could be the brushes are
>>dirty and need replacing or the bearings are shot and
>>the motor itself needs to be replaced (or rebuilt, but
>>it's pretty old already).
>>
>>
>>
>
>______________________________________________________________________________
>Send postings to clayart@lsv.ceramics.org
>
>You may look at the archives for the list or change your subscription
>settings from http://www.ceramics.org/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at melpots@pclink.com.
>
>
>
Jean Lehman on sun 25 may 03
I also have an old Brent C which was making noise and vibrating. I
replaced the frayed cord which helped a bit. But it still vibrated. I
called my supplier (Penn-Mo in Harrisburg) who was pretty sure it was
the ball bearings. So, I have a new wheel head assembly ready to
install. Unfortunately I can't report on the outcome because I have
been too busy to get it done. BUT, the cost was less than $100. I
would be pretty sure it is the motor before taking that step!
Jean
>I have an old Brent C which is making quite a bit of
noise and vibrating, especially at high speeds...
--
-------------------->
Jean Lehman,
jlehman73@earthlink.net
in Lancaster, PA
http://www.art-craftpa.com/sfpn.html
Check in on line to see The 11th annual (2003)
Strictly Functional Pottery National exhibition, juried by Wayne Higby.
It opened April 26, and will be open through Memorial Day, May 26, 2003.
David Hendley on sun 25 may 03
First, you need to find out for sure if the problem is in the motor.
Take the belt off the motor and run it. Is the loud hum and vibration
still there?
If not, it is the belt or the wheelhead bearings.
If so, it could be the motor or the controller. Take the motor to an
auto alternator/starter shop and ask them to test it.
If the motor tests OK, you need a new control box and/or pedal , which
will only be available from Brent.
Motor brushes do not "get dirty", but they wear out (wear down to
nothing, like a brake shoe). To check them, or replace them, you
simply remove the 2 large screws on the body of the motor.
There should be at least half an inch of black carbon material, curved
to fit the motor armature on one end, and attached to a wire and spring
on the other end.
New brushes should cost on the order of $20 from a motor supply place
like W. W. Grainger.
It is not too hard to replace worn out motor bearings. They will be about
$30. I sent in step-by-step instructions for doing this to Clayart a few
years ago, under the heading "The day the crickets died".
If you need new brushes or bearings, take the old ones with you to the
store, to make sure you get the right replacements.
Pottery wheel motors are DC (direct current), not the more common
AC (alternating current). Sears does not stock such motors, but
a place like Grainger's does.
I'm not sure I've kept up with prices, but it should be under $200 for a
new one. Again, take your old motor, to show them what you want.
David Hendley
Maydelle, Texas
david@farmpots.com
http://www.farmpots.com
----- Original Message -----
> I have an old Brent C which is making quite a bit of
> noise and vibrating, especially at high speeds (with
> no clay on it). It's not squeaking or whining, more
> of a loud hum but no grinding sound. There's no
> visible problem (to me, at least) with the mounting of
> the motor or the flywheel/belt other than the belt is
> very slightly frayed.
>
> I did call Brent and spoke with someone about
> repairing it. From what I've been told (or read in
> the clayart archives), it could be the brushes are
> dirty and need replacing or the bearings are shot and
> the motor itself needs to be replaced (or rebuilt, but
> it's pretty old already).
>
Clay Art Information on tue 27 may 03
Good morning,
Try to run the motor, without the belt on the pulley and observe the
noise coming out from the motor.
Check if the pulley attached to the motor is tight, I'm not quite sure
how Brent mounts it, but kindly check, the pulley may be loose. Another
thing to consider is to replace the belt, most of the belts use for
Wheels are poly - V belt, like the Shimpo models, some of them have
sewing machine belt. You can check the information thru the belt
itself, there are numbers that indicate the size and type, this would
help you in getting the right replacement ( eg. M23 ) . Replacement
Belt is needed, if you hear a thumping sound.
If you can access the Carbon brushess easily, check the condition of
the brushess. Try to re-insert the brushes and then check again by
running the motor on normal operation . If a lot of dust can be
observed, the rotor (center) is hitting the magnet and creating
friction, the motor however will still function okay, there will be
noise, but the function of the motor will be sufficient to get your
wheel running. If noise is a big factor, your last resort is to buy a
replacement motor.
Wish you good luck.
Best regards,
Arthur Morales
Nidec-Shimpo America
(800) 842-1479 ext. 150
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