Paul,   I remember the big motor starters and had some which also
  did from one to five speed control of the three phase motor. They
  require maintenance on the solid silver contacts and resister
  elements and fail due to heat cycle fatigue and arcing as the points
  close.  We usually changed to a Wye Delta starter contactor rather
  than fixing them.


  My prefferred method of transforming
  power is with a hydraulic piston pump. A variable displacement pump
  that will fit in a 10" cube can easily need 120 HP to turn it at
  3500 RPM and full flow at 3000 PSI. One common frame size goes up to
  60 GPM.  If you know the pressure and RPM of the pump you can
  determine HP to a fraction of a horsepower. There are also
  mechanical lever controls available on these pumps ( think Bobcat
  skid loader) that can set the displacement for different loads.

     The pumped oil would be sent thru an adjustable valve or an
  orfice to return to the tank and the HP would go off as heat. This
  makes a lot of heat and in fact I used to have a relief valve that I
  could drop the pressure to just 600 PSI to warm up the oil in the
  winter if the hydraylics were outside the building.This was done to
  reduce the viscosity of cold oil to prevent pump damage.


  If
  you set pump volume at 1000 Rpm down to where the turbocompound can
  turn it then read the pressure rise  as the HP rises and record the
  pressures you can read the HP of the pump curve charts.

  george grimes




  A power steering pump would be easy to integrate and
 control pressure with an adjustible pressure relief valve.
 Dale Davies

 Thanks for all the ideas and help guys.
 I am going back to the old standby of a prop dyno.
 Much cheaper and less tech risk.

 Paul Lamar


 Paul,   To mount the gearbox in the illustrated stationary ring you might
consider a needle bearing cam follower. They are available with the shaft
eccentric ( called camcentric style) so you can preload or adjust centering
of the gearbox.  My brand of choice is McGill. You might also use the "V"
roller face and only need 4 of them, however the eight you have shown is
more stable and would not restrict heat expansion of the drive shaft.

george grimes

Good idea. I'll look into that George. I have some of those lying around.
At one time I was going to use them on a slide throttle before
I had the Teflon idea. I think a ball bearing and a bolt is cheaper
however:)

Paul Lamar