----- Original Message -----
Sent: Sunday, February 05, 2006 7:15
PM
Subject: [FlyRotary] Re: Single rotor
smooth as silk now
Rusty,
Really good news, you might get Tracy to supply
some alternative rubber isolators - probably harder ones? but I'm
guessing!
George ( down under)
Hi George,
Tracy's drive is gone. I sold it to someone on
the list. I'm guessing the dampener will have to be much more
significant than what is included in Tracy's drive, so I'll start from scratch
when I get done with the RV-8. BTW, how is your engine coming
along, and what are you using for a redrive? I'd rather just
buy one if it exists (hint, hint).
Cheers,
Rusty
Hi
Rusty,
let
me throw something in here on the dampener. Tracy's dampener is not built
to take up a lot of torque vibration at low rpm. What we need on the single is
having the soft elements closer to the center line of the e-shaft, allowing
more movement in them, eg. having a softer coupling = lower resonant
frequency, and at the same time utilizing some of the dampening
characteristics inherrent in the rubber. The closest to that requrement I
could come up with, is the do-nut shaped coupler used on Rotax and Hirth
engines. They are also available in different Shore values. I have not found a
US source yet.
I have not
demonstrated yet if this solution is sufficient, but analysis indicates that,
if the idle speed is 1500rpm or above, it should be
ok.
All this
does not eliminate the careful selction of a sufficient fly
wheel.
Richard
Sohn
N-2071U