Mark, I have an extra RX8 trigger wheel
    and my next door hangar neighbor is making a hub
    for it as we speak.

    http://skycraftsurplus.com/dcmotorhighrpm.aspx

    I will try to find a better motor as the shaft
    diameter on that one is a bit marginal IMHO.

    Paul Lamar

    Paul,

   How about using an air grinder?

   Mark

   That would work. I checked mine and it goes to 22,000 RPM.
   The question is.... how do you control the speed?

   Paul Lamar



   Hi Paul,

   Use a pressure regulator and slowly bring the pressure up until you get
  the
   RPM you want. Check with an optical tach.

   Dale Davies

   The trouble with that is the air pressure regulator on most compressors
   are not proportional. It is what we call in the servo biz; bang bang.
   Too high turn it off. Wait. Too low turn it on and wait.
   Right amount turn it off. Repeat. So the RPM is cycling up and
   down. Which may still work for our purposes but not ideal.


   Paul Lamar

  Paul,  To do speed control on pneumatic or hydraulic motors you need to
  meter the volume not the pressure.  This is done with a flow control which
  does not cycle on and off,  such as a needle valve.  Additionally the flow
  control needs to be on the exhaust  port of the motor to control the speed.
  This will provide full torque capacity of the motor. The torque is
  controlled by the inlet pressure which in this case would be fixed at the
  tank pressure of your shop air. Set the tank pressure a little under the
  rated pressure of the motor and don't use a line regulator. If you use a
  line regulator it will need a 100 foot hose for an accumulator to dampen
  pressure pulses from the regulator.

  george grimes



Paul,
Here's another option... Use a wood router with an aftermarket speed
control.  I bought a $20 speed control unit from Harbor Freight.  But if you
don't have a router, this might be an expensive solution.

Mark

That sounds pretty good. I have a router and Harbor Freight
is close by.

Anheim Motors has not called me back so I am going to look in
McMaster Carr cat.

I have got to go out to the hangar and see how Jim is doing
on the RX8 hubs. I'll sell you one if you want it. Jim is making
two.

----------------------------------------------------------

Harbor freight speed control is the hot tip Mark. Thanks.

I would put this thing in a 2 foot square 3/4 inch thick plywood box
in case something goes wrong. You don't want to kill
anybody. My router will go to 22,000 RPM.

BTW this combination would make a great spindle motor
for a small NC mill. Routers have good bearings as
they are subject to high side loads.

Paul Lamar