OK.  So Tracy's re-drive is loose.  Would not rubber bushings make it MORE loose?  Or would that turn on more complex considerations such as the elasticity of the rubber, etc.?
Lookin' for easy answers to hard questions again? :o) .... Jim S.

Al Gietzen wrote:

I realize that these are relative terms, but my opinion is that Tracy’s re-drive would not be called “tight” tolerance.  There is; what – ½ back and forth play at the prop tip?  As I recall, Tracy had given this some consideration, and chose to keep the relatively “loose” tolerance.

Subject: [FlyRotary] Re: Torsionals

Ed,

Assuming (key word here) that Tracy's PSRU can be regarded as "tighter

tolerances", mightn't rubber bushings effectively "loosen" the tolerances and

get us INto more trouble than they get us OUT of?

Just wonderin' .... Jim S.

Ed Anderson wrote:

> Hi Greg,

>

>    Welcome to the list.

>

>  Torsional vibrations and resonance are a fairly complex topic.  ..  In

> generally tighter tolerances raises the resonant frequency of an assembly

> and looser tolerances lower it.  Tighter tolerances are generally more

> expensive than looser.  ...By the way, since the rotary does not have a

> negative torque region in its

> power curve this problem is minimal and can generally be handled by some

> simple dampeners such as rubber disks, etc.

>

> Ed Anderson