Dan,

You're right about one thing. I don't get what your objection is.

Are you saying the springs immediately begin to compress at the first sign
of torque? Hence the plot beginning at 0-0?

I don't see how this is possible unless the springs were installed without
any preload at all. My understanding is that the springs in a clutch disk
are under preload, so the torque has to rise to a certain level before they
will compress. Until that point it is a solid coupling.

If the springs had no preload, it would never be a solid coupling. It would
contantly be compressing and decompressing. How could that kind of clutch
even be usable in a car? It would be lurching all the time.

Also glad you mentioned the rubber torsional coupling brought up by the
poster in reference to the Alfa driveshaft.

The Rotax boxes you mention use this for the same reason the Ross box uses
the clutch disk with the springs. But as I was trying to point out, the
springs are not used to actually isolate the vibrations but to introduce
variable stiffness into the system.

Regards,

Gordon.







"Dan Horton" wrote in message
oups.com...
Up until that point the springs are not compressed and the coupling
is in effect a solid coupling.

Good God, he still doesn't get it.

Gordon, plot the supplied data and study at it carefully. If your
assertion were true, the plot would not leave the Y axis until reaching
some elevated torque value. Note that the real plot begins at 0-0.

Dan