Logan Johnson on thu 13 sep 07
Hi Gang,
A friend of mine asked for my help with a wheel & I told her the best help I could give her is to ask the folks on Clayart about her problem. She did contact Simpo directly but I guess they weren't very helpfull 'cause she still has the problem. Can any of you help?
Thanks SO much !!
Logan
Hi Logan,
Thanks for forwarding this for me.
The Wheel:
I have a used Shimpo Velocity electric wheel (model V75) that has been causing me some problems. It has a bit of a pause, bump or tic once every revolution. I have narrowed down the problem and I know that what I am feeling is not caused by the splash pan, unfamiliar or poorly wedged clay or the height or type of stool I am using. I regularly throw on a Brent where I teach, and I have thrown on Lockerbie kick wheels, Boss electric wheels and some other brand years ago. This Shimpo is the only one that has caused me problems.
History:
Immediately after I bought the wheel, I was able to use it only a few times. I do not remember a problem at that time, but I can’t say for sure that there wasn’t one. Since then I have moved and it is possible something happened during the move.
The Problem:
I don’t notice much of a problem when I am centering the clay fast and low on the wheel head, but once I bring the clay up to about 4 or 5 inches and slow down the wheel a bit, I start to notice the bump. When I first noticed it, I thought I had an air bubble or something dragging in the splash pan, but since then, every time I throw I have the same problem. I removed the splash pan and could still feel the bump once every revolution. I slowed down the wheel so that it was barely moving and noticed that there seemed to be a drag or a slow spot once every revolution.
Troubleshooting:
With the help of my husband (he’s a mechanic, but not familiar with pottery wheels), I took apart the wheel to look for the problem. He took off the wheel head and checked the shaft, but he doesn’t believe it is bent. We removed and replaced the belt (same belt, just put it back on), and didn’t notice anything unusual. He sprayed some lubricant in the motor, but that also didn’t seem to affect anything. I threw while he watched the belt and motor, but didn’t notice anything odd (I had only a bit of clay wedged before he went to work, so he wasn’t able to watch me for long).
Once I got more clay, I threw on the wheel with the belt exposed until I got the ticking again. Then I slowed down the wheel speed while watching the belt from underneath. With the wheel spinning at its slowest speed, I could see a pause once every revolution (I judged this spot by the writing on the belt). There doesn’t seem to be anything visibly wrong with motor, shaft, wheel-head or belt other than this drag. The drag does affect my throwing; it creates a weak point where the clay pauses between my hands.
Thanks for any help or suggestions.
-Rachel Dorn
Logan Johnson
Yakima Valley Pottery & Supply
719 w. Nob Hill blvd.
Yakima Wa. 98902
(509) 469-6966
www.yakimavalleypottery.net
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Michael Wendt on fri 14 sep 07
Logan,
Have your friend remove the belt and rotate the wheel
head by hand to check for the catch. If there is such a
catch, the bearings could be at fault and may need to
be
replaced.
Since it appears to occur only once per revolution,
the fault cannot be in the motor since most wheels'
motors run at 10 or more revolutions for every 1
revolution of the wheel head.
A faulty belt ( often the mold parting line or a
brittle crack or a chunk missing ) can also be the
cause so examine it carefully.
If the wheel is not used very often, a "set" can
happen in a belt where the turn around the small
pulley (or if this is an old ring-cone Shimpo, the
drive ring) forms a depression from sitting in the
same spot for a long time. If warmed up for a
while, it may go away.
Just a few ideas... any more?
Regards,
Michael Wendt
Wendt Pottery
2729 Clearwater Ave.
Lewiston, Id 83501
U.S.A.
208-746-3724
wendtpot@lewiston.com
http://www.wendtpottery.com
http://UniquePorcelainDesigns.com
Once I got more clay, I threw on the wheel with the
belt exposed until I got the ticking again. Then I
slowed down the wheel speed while watching the belt
from underneath. With the wheel spinning at its
slowest speed, I could see a pause once every
revolution (I judged this spot by the writing on the
belt). There doesn't seem to be anything visibly wrong
with motor, shaft, wheel-head or belt other than this
drag. The drag does affect my throwing; it creates a
weak point where the clay pauses between my hands.
Thanks for any help or suggestions.
-Rachel Dorn
Kris Bliss on fri 14 sep 07
hi logan, rachel and all
i too had the misfortune of owning a velocity wheel.
i was stupid enuf to buy 2 !!one was so bad noise,
jerking etc.. i sold for coupla hundred to a young
man that is a mechanical engineer. after he had
rebuild both several times (in one year!) i still
have 1...LOUD..
he said he could not figure out the problem , but
every time he rebuild it (using same parts).. the
problems would go away for a bit then slowly come
back..he sail flipping the brushes seemed to help.
absoulutly no help from shimpo during the whole
ordeal. there only comment was, we don't make those
anymore. and a sales pitch for the whisper.
i now throw on a thomas stuart.
good luck, rachel
my advise? use the piece of @#$% for a banding
wheel or something. save your money and buy a
thomas stuart.. they are not that expensive..
bliss in sunny alaska
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