I think what we really need for the torque damper is a fliud
 coupling. I was at the Camarillo air show yesterday and they had
 an unprecedented collection of war birds. No less than two flying
 P38's among many others.

 They also had a restored early Northrop flying wing.

 I turned the prop both ways and it rotated freely.
 I asked some of the CAF types if it flew in :)
 They said yes. They said it had torque converters but
 what I really think they meant were fluid couplings.
 Maybe they were really torque converters Northrop got in a
 junkyard :)

 The torque converter is closely related to a fluid coupling
 and is widely used in automatic transmission. The stall
 speed is about 2000 RPM so the engine can rotate freely
 up to about 1500 RPM before a lot of torque is transmitted.

 Our problems are not so much torsional resonance but
 gear box chatter.

 I think a fluid coupling will solve the problem once
 and for all.

 http://pt.rexnord.com/products/couplings/true_torque_fluid_couplings/fluid-couplings.asp



 Falk True Torque Fluid Couplings

 A fluid coupling allows the motor to accelerate independently to full
 speed,
 the driven load has been isolated by the fluid coupling.

 Paul Lamar

Hey Paul,

I think you're on to something here.  Unfortunately the Falk True Torque
fluid couplings are limited to 1800 rpm.  We would exceed that at idle.
 Maybe something could be borrowed from some automotive application
that would meet our needs.

 Mark LaPierre

Look back at my emails on a coupling I am using. I do not have flying
time but I have extensive test stand time at near or full power.

chris smale