SBRANFPOTS@aol.com on mon 4 jan 99
Oh boy..........this is where I step in. When somebody says "there is no
repair possible". The older Shimpo's operate on a friction drive system where
there is a cone on the motor shaft that comes in conmtact with a rubber drive
wheel that is directly connected to the wheel head. As the contact between the
cone and the drive wheel gets closer, the wheen speeds up. Precise adjustment
occurs when the motor shaft and the wheel head shaft are PERFECTLY
perpendicular. If they are not then the wheel will not maintain a steady speed
and it speeds up by itself. After some time this can come out of alignment. To
make the adjustment (which is VERY tricky and time consuming) you must loosen
the screws that attach the motor to the motor mount and carefully slide the
motor so it is again in perpendicular position. It can take numerous trial and
error efforts or you can be lucky on the first or second attempt!
Please don't erroneosly post advise that says no repair is possible unless
that is in fact the truth!!
Steven Branfman
The Potters Shop
Vince Pitelka on tue 5 jan 99
There seems to be some confusion about the motor mounting system and the
adjustments on the early Shimpos - the RK-1 or RK-2. In both these wheels
the motor is mounted at an angle. On the RK-1 the entire motor-mount
assembly slides horizontally on a shaft, and the upper surface of the drive
cone remains perfectly horizontal. On both models the rubber friction ring
is mounted on a jack-shaft, with a belt drive to the wheelhead shaft. As
you step on the pedal, the point of the cone comes in contact with the drive
ring, and as you depress the pedal the rubber ring contacts a larger
diameter of the cone, increasing the speed. The mounting setup on the RK-1
is so sturdy that they very rarely need adjustment. There is a simple
adjustment for cone-ring contact pressure, but that does not change motor
allignment. The RK-1 rarely ever has a problem with the speed creeping.
You can take your foot off the pedal and it stays right where it is. I have
been using a RK-1 for 25 years, and the only time I have ever adjusted the
cone-ring pressure was once when I replaced the drive ring about ten years
ago.
But that is all beside the point, because the wheel in question is the RK-2,
where the motor is mounted on the pedal shaft. This runaway speed problem
is characteristic of the RK-2, and as much as I love Shimpo equipment, this
wheel is a piece of crap, and Shimpo should be ashamed of themselves for
ever putting it out on the market. The cone on the RK-2 is curved, and when
you step on the pedal it tilts the motor the tip of the cone comes in
contact with the rubber friction ring. As with the RK-1, as you depress the
pedal further, a larger diameter of the cone comes in contact with the
rubber ring, increasing the speed. There are two major adjustments in the
RK-2. There is a friction plate on the pedal shaft which determines
resistance to movement, and there are mounting bolts which determine motor
position, changing motor-ring contact pressure and motor-ring allignment.
Another post today from Richard Mahaffey does a good job of explaining this.
Good luck -
- Vince
Vince Pitelka - vpitelka@DeKalb.net
Home 615/597-5376, work 615/597-6801, fax 615/597-6803
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
John K. Dellow on wed 6 jan 99
Vince , is there any difference in the set up on the rk2 model made in Japan &
the one made in the USA ?.
John Dellow the flower pot man
Mike Gordon on wed 6 jan 99
Stephan,
I hope you read Vince's msg. about the R-K2. I agree with him, after it
gets to the point of NEEDING adjustment its a waste of time, speaking
for a classroom situation, a chunk of clay is a quick fix. I've tried
the " adjustment " thing to no avail. Mike
Vince Pitelka on thu 7 jan 99
>Vince , is there any difference in the set up on the rk2 model made in Japan &
>the one made in the USA ?.
>John Dellow the flower pot man
John -
Steve Branfman sent me a post saying that the design on the RK-2s changed in
the latter part of the run. I do not know the specifics of that change, but
if you need to know, email Maxine Cohn at Shimpo - Shimpopot1@aol.com. They
are always very helpful.
Good luck, and I'd be interested in what you find out.
- Vince
Vince Pitelka - vpitelka@DeKalb.net
Home 615/597-5376, work 615/597-6801, fax 615/597-6803
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
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