David Hendley on sun 12 nov 00
There are 3 things that can cause a chirping noise in your wheel:
1) Bad belt
2) Bad bearing on the wheelhead shaft
3) Bad bearing in the motor
To find out which it is, take the belt off and look for cracks,
splits, or warn places on the belt. Spin the wheelhead
around - it should spin freely, with no clicks or slow-downs.
Turn on the motor and accelerate with the footpedal.
It should be quiet.
Of course, replacing the belt is easy.
Replacing the wheel bearings is also easy. There is no reason
to call the wheel company for new bearings; just go to
the bearing supply store and get new ones. Take the old ones
with you. Always replace both bearings.
It is worthwhile to go ahead and buy a gear (bearing) puller.
With that and a good set of long handled Allen wrenches
you will be able to dismantle the wheelhead and bearings.
Earlier this year, I posted step-by-step instructions for replacing
the bearings in a DC potter's wheel motor. I've copied
them below.
Good luck,
--
David Hendley
Maydelle, Texas
hendley@tyler.net
http://www.farmpots.com/
I bought my Pacifica GT 800 22 years ago (pre-Laguna)
because it was the quietest wheel I had ever seen (heard).
Well, it's been getting louder and louder for years.
Ridiculously loud.
I finally did something about it last week. First I took
off the drive belt, to see if the noise was coming from
the motor or the wheelhead. A quick spin of the wheelhead
and acceleration of the footpedal revealed that the motor
was making a chirping/grinding noise.
The next step was to remove the motor, and have a look.
There's really not much to a DC motor. I decided it HAD
to be bad bearings causing the noise, so I removed them
and carried them to the bearing store, to buy some
replacements. $30 and 2 hours later the old GT sounded
like it was 1980 again.
April 28, 2000. The day the music died.
If your DC motor is making noise don't be afraid to take
it apart and replace the bearings. It's really no big deal.
Here are some instructions:
First, remove the brushes. These are the black carbon-looking
things with springs that rub against the communicator
on the motor armature. There will be 2 caps, with screwdriver
slots, opposite each other, on the motor housing. Just un-
screw them and remove the brushes.
Remove the fan cover. 4 screws. Straightforward.
Remove the fan blade from the motor shaft. Mine had
a tab that you pressed while you pulled it off the shaft,
some might use a hex-head set screw.
Remove the belt pulley. This will have a set screw, and you
need the proper size hex wrench. You will probably
also need a gear puller. DO NOT bang on the shaft with
a hammer; go to the hardware store and buy a gear puller.
Notice that the shaft has a flat place. Remember exactly
where the pulley was on the shaft, so you can re-install
it later.
Remove the nuts from the long bolts that hold the motor
together. You will see them when you remove the cooling
fan blade. You might also have to remove a little plate
where the wiring enters the motor.
Take the motor apart. It will be in 4 pieces: the top, the
bottom, the main body, and the armature.
You might need your gear puller again to pull off the top
and/or the bottom.
Remove the bearings. They will be on the armature shaft,
one towards each end. Again, use the gear puller, if
necessary. There may be some washers on the shaft;
remember where they go.
To install the new bearings, you might need a short piece
of pipe. Put the bearing on the shaft, put the pipe on
the bearing, and give the pipe a few taps with a hammer.
The pipe will move the bearing without hitting the shaft.
Brushes wear as they are used. If your motor still makes
some noise when you test it with the new bearings, it could
be coming from the brushes. Try switching them and/or
rotating them 180 degrees. As the brushes wear, they
conform to how they are installed and should quiet down
even if you don't experiment with changing them around.
--
David Hendley
Maydelle, Texas
hendley@tyler.net
http://www.farmpots.com/
----- Original Message -----
From:
To:
Sent: Thursday, November 09, 2000 11:43 PM
Subject: question for vince
| At Mel and Dannon's workshop at ACC, you told us we should know how to
take a wheel apart and put it back together, know how to fix it and how it
works. It has been bugging me ever since.
|
| I am one of those power-tools-are-a-girl's-best-friend types, and not
afraid to dig in. But here's the situation. I have a Brent, maybe 10 or 15
years old, got it second hand. It got left out in the rain once, and fell
out of a wheelbarrow right upside down, gets been hauled around in the back
of a pickup, and it just keeps running, level and balanced and smooth. Just
in the last few weeks, though, it has started to make a tiny little cricket
sound as it turns, which speeds and slows as the rotation does. Runs like a
top, just chirps quietly as I work. Kind of soothing really. But I have your
voice in my head and I get the feeling I should take it apart and fix it.
Considering what they cost, though, and how lost I would be without it for
even a day or two, I hesitate -- "if it ain't broke, don't fix it." What's
your call on the cricket noise? Thanks. Kelly in Ohio
|
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