>

     >>> Giffen Marr wrote:
     >>>
     >>>> Paul
     >>>>
     >>>> Am I to understand that the TC Drive is to be driven by a shaft
     >>>> from the
     >>>> Turbo compressor? If so, aren't shaft rotational speeds of 60k to
     >>>> 80k going
     >>>> to present a problem?
     >>>>
     >>>> Giff Marr
     >>>> LIV-P/20B 45%
     >>>>
     >>>>
     >>>
     >>> What problems did you have in mind? This is what I tink I am going
     >>> to use in the 1/2 inch size.
     >>>
     >>
     >> Paul, you are joking right?
     >> Mark W.
     >>
     >>
     >> No Not joking. What problems do you see?
     >> --
     >> Paul Lamar ...No rotor no motor.
     >
     >
     > Lack of balance, lack of strength, a horrible failure mode with
    an easier
     > released projectile.
     >
     > At 80K RPM, any imbalance will be be exciting it with 480KHz (two per
     > rev).
     > At this frequency, you will at least wear out the metal to metal
    contact
     > points in the universal (although as Reeves says, you will be very
     > unlikely
     > to get up to this RPM.). Turbines normally use some sort of splined
     > coupling, a rigid coupling with a floating oil damped bearing, or
    driving
     > lubs these days.
     >
     > Be really careful testing this Paul.
     >
     > Mark

SNIP

Wait a minute...  80,000 RPM is 1333Hz or 1.3KHz.  2per rev is 2.67KHz.
Not 480KHz as stated above.  Divide by 60 to get from RPM to Frequency.
Not multiply. I think it would be tough to find a mechanical system that
resonates at 0.5MHz...  Admittedly, 2.67KHz is pretty high frequency.
Though that just tells me it should be easy to damp..


Regards,

Matt-

Oops, good call Matt. What I was trying to point out is that
you are into the HCF regime.
Mark W.




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