Vince Pitelka on mon 14 dec 09
Sean Burns wrote:
"One of the RK-10's (grey body) at my school had smoke coming out of the
motor today- its an oldie - we let her cool down and I retried the motor- a
whining sound but the cone still spun- stinky smell. Wondering if anyone ha=
s
had a smoker motor of a shimpo repaired/rewound or whatever and had it see
a useful return to duty."
Hi Sean -
They do that occasionally. When I got to the Craft Center in 1994 we had a
fleet of RK-2s, and we still have a few of them around. They have
permanently-sealed bearings, so there is no maintenance, and eventually the
motor's just overheat and start smoking. There is no gain in having such a
small motor rewound, so it is a matter of getting an original replacement o=
r
adapting a different motor. Hopefully you will be able to find one with th=
e
exact same frame, and the coding on the motor tag should identify the frame
configuration. If you take the whole motor to an electric motor shop they
should be able to help you find a replacement, if one is available. There's
a lot of equipment around with metric motors, so hopefully they can find on=
e
without having to go to Shimpo. If you have to adapt a western motor, you
will need to have someone machine the bore on the cone to fit the western
shaft size, because the original Shimpo motor shaft is metric. That's what =
I
had to do in the late 1970s when I built a copy of a RK-2 using a Shimpo
cone and ring. And of course as you probably know, the position of the moto=
r
in relation to the friction transmission is critical, so adapting another
motor with a different frame has its own set of challenges.
Good luck -
- Vince
Vince Pitelka
Appalachian Center for Craft
Tennessee Tech University
vpitelka@dtccom.net; wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka
Sean Burns on mon 14 dec 09
Hi Folks- question
One of the RK-10's (grey body) at my school had smoke coming out of =
=3D
the=3D20
motor today- its an oldie - we let her cool down and I retried the motor-=
=3D
a=3D20
whining sound but the cone still spun- stinky smell. Wondering if anyone =
=3D
has=3D20
had a smoker motor of a shimpo repaired/rewound or whatever and had it se=
=3D
e=3D20
a useful return to duty.=3D20
As an aside an not to be a wiseguy- well maybe a little- anything a ki=
=3D
d=3D20
makes on this wheel is handmade in my opinion.
And sorry for the html - I cant figure out how to get rid of it.
thanks,
Sean Burns
Williamsburg, Ma.=
=3D
Vince Pitelka on tue 15 dec 09
Ric Swenson wrote:
"it is the difference between the lubricated bearing and gear...permanentl=
y
sealed bearings....? 0r ring cone on the Shimpo?
bearings are sometimes used to transfer power from one direction to
another...and shimpo uses a cone drive... Brent use a belt... kick uses a
foot... chinese use a hand pole....
Hi Ric -
Not sure what you mean by the above. Bearings are not used to transfer
power. Every electric motor has bearings or bushings on both ends of the
shaft to support it and allow it to spin freely. Bearings can be ball
bearings, roller bearings, or needle bearings, and bushings can be babbit o=
r
brass or sintered bronze.
The Shimpo RK-1 uses a straight-taper drive-cone mounted on the motor outpu=
t
shaft, with the motor mounted diagonally on horizontal slides so that the
upper surface of the cone is level. Step on the pedal, and the tip of the
cone engages the rubber drive ring and the wheel goes slow. Step further,
and a larger diameter of the cone engages the rubber ring, speeding up the
wheel. Ingenious system. Too bad they spoiled a good thing in the RK-2,
where the motor is mounted on a pivot, and the surface of the cone is
actually curved. Step on the pedal, and the motor tilts, bring the tip of
the cone in contact with the rubber drive ring, step further, etc. Except
that the system doesn't work nearly as well as the RK-1. Thankfully, it wa=
s
the RK-1 that I copied in building my wheel in the mid 1970s. I didn't hav=
e
much experience with the RK-2 until I came to the Craft Center in 1994, and
then I got way too much experience with them maintaining the herd of RK-2s
that we had. Why couldn't they have bought RK-1s? Maybe because they were
not making them anymore in 1980 when they equipped the Craft Center.
The later Shimpos used various systems, including a metal-to-metal traction
system on one of their wheels before they went to the direct-drive
variable-speed motors currently used on the Whisper series.
- Vince
Vince Pitelka
Appalachian Center for Craft
Tennessee Tech University
vpitelka@dtccom.net; wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka
Philip Poburka on tue 15 dec 09
Any 'Sealed' Ball Bearing...for dismantling the Machine and accessing the
Bearing's sides...
One may perorfate the side 'Seal' with an Ice Pick or similar, or pry part
of it up...thus allowing fresh Grease to be injected.
Heating the Bearing, and, the Grease to be injected, good-and-HOT, allows
better results.
Ideally, one does this prior to a catastrophic lubrication-related failure.
Only slightly more effort, and, one may remove and replace the Bearings.
I never liked 'Sealed' Ball Bearings.
No manufacturer worthy of respect, or, who respected their Customers, would
ever use them.
For two cents worth of care, they could have used Lubricatable/Maintainable
Bearings, and, Oil Cups, or, Zerk/Alemite Nipples.
Oye...
Anyway...
If a Machine is otherwise meritorious, but has 'Sealed' Bearings, usually,
one can convert fairly easily to Lubricatable Bearings, by installing the
appropriate Bearing type, and, drilling and tapping a few small holes.
Love,
Phil
lv
----- Original Message -----
From: "Vince Pitelka"
> Sean Burns wrote:
> "One of the RK-10's (grey body) at my school had smoke coming out of the
> motor today- its an oldie - we let her cool down and I retried the motor-
> a
> whining sound but the cone still spun- stinky smell. Wondering if anyone
> has
>
> had a smoker motor of a shimpo repaired/rewound or whatever and had it se=
e
> a useful return to duty."
>
> Hi Sean -
> They do that occasionally. When I got to the Craft Center in 1994 we had
> a
> fleet of RK-2s, and we still have a few of them around. They have
> permanently-sealed bearings, so there is no maintenance, and eventually
> the
> motor's just overheat and start smoking. There is no gain in having such
> a
> small motor rewound, so it is a matter of getting an original replacement
> or
> adapting a different motor. Hopefully you will be able to find one with
> the
> exact same frame, and the coding on the motor tag should identify the
> frame
> configuration. If you take the whole motor to an electric motor shop they
> should be able to help you find a replacement, if one is available.
> There's
> a lot of equipment around with metric motors, so hopefully they can find
> one
> without having to go to Shimpo. If you have to adapt a western motor, you
> will need to have someone machine the bore on the cone to fit the western
> shaft size, because the original Shimpo motor shaft is metric. That's wha=
t
> I
> had to do in the late 1970s when I built a copy of a RK-2 using a Shimpo
> cone and ring. And of course as you probably know, the position of the
> motor
> in relation to the friction transmission is critical, so adapting another
> motor with a different frame has its own set of challenges.
>
> Good luck -
> - Vince
>
> Vince Pitelka
> Appalachian Center for Craft
> Tennessee Tech University
> vpitelka@dtccom.net; wpitelka@tntech.edu
> http://iweb.tntech.edu/wpitelka
Sean Burns on tue 15 dec 09
Vince wrote:
>there is alot of equipment around with metric motors, so hopefully they =
=3D
can=3D20
find one >without having to go to Shimpo. If you have to adapt a western=3D=
20=3D
motor, you>will need to have someone machine the bore on the cone to fit=3D=
20=3D
the western>shaft size, because the original Shimpo motor shaft is metric=
=3D
.=3D20
=3D20=3D20
Vince-=3D20
Thanks for the reply- I did not think of the metric factor, I am alw=
=3D
ays in
western mode I geuss. Years ago I took one of those smokers apart with th=
=3D
e=3D20
kids and found a fiberglass type bearing ring that looked like the culpri=
=3D
t- we=3D20
went online and found a schematic diagram for that motor with a part # an=
=3D
d=3D20
actually called Shimpo trying to order the part to see if we could get th=
=3D
at one=3D20
working. They said they would check with the Japanese manufacturer to see=
=3D
if=3D20
they could come up with it but we never heard from them again -so we woun=
=3D
d=3D20
up using it for sculpture parts after it was totally dissassembled by a c=
=3D
urious=3D20
kid- imagine that. I also checked for a relacement motor from Shimpo thru=
=3D
my=3D20
local supplier before we did that and that option was too pricey to make =
=3D
it=3D20
worthwhile. Checking with a local motor shop makes sense- I hope I can co=
=3D
me=3D20
up with a cheap replacement- we cant kill the body of these things- but I=
=3D
=3D20
hate to see and smell that smoke- it means trouble.=3D20=3D20
regards,
Sean
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