Since we are talking about torsional resonance, does anyone know how to
figure
the
design of a rattler type damper for a one rotar? Dan Stanzione


I think you are confusing the once per rev high torque pulse with the
e-shaft torsional resonance. The one rotor torsional resonant frequency
of the e-shaft is way too high to be a problem. Same for the 2, 3 and 4
rotor. That is why you never see torsional dampers on them like are
common on piston engines with
rubber bands or wet spaghetti for crankshafts :).

The torque pulse effect depends on what it is connected to. The problems
are with the gear boxes and gear impact loads.

The Sky Ranch Engineering Manual. Has a section on pendulum torsional
crank shaft dampers starting on page 417. The telephone number to buy
this book is
(916) 421 7672. The author is John Schwaner.


Paul Lamar


The book is available from amazon.com too.


 Mark LaPierre