> Hey,
      >
      > Why don't we use Belleville washers on wood propeller bolts?
     Seems like
      > this is a similar idea to using constant torque hose clamps...
     As the
      > wood shrinks and swells (due to changes in temp and RH), the
     washers keeps
      > a relatively consistent clamping force on the system.
      >
      >
      > Regards,
      >
      > Matt-
      >
      >
      > I have always wondered about that myself Matt.
      >
      > Paul Lamar ...No rotor no motor.
      >

     [Herb Sanders] Make that constantly inadequate torque.

When I tried to do this some time ago the only Bellevilles I could get
were flattened before the correct torque was reached. Now I can't recall
what the correct torque is!
I have now found someone who can supply various thicknesses.

John Evans

A little suprising, as many wood props are only good to about 25ft/lbs on
a 3/8" bolt (before you start damaging the wood).  Seems like it would be
pretty easy to get the washers for that clamping force.  Plus you can
stack the washers to get more force.


Regards,

Matt-

I am convinced that the Bellville washer approach is well worth pursuing.
Inspired by an E mail from Paul Lipps, I have revisited this idea,
and was working with others to prepare a report. We have made numerous tests
with washer stacks measuring torque as a function
of wrench angle and have identified numerous combination which will preload
in the desired torque range before flatening. My illness has put much of this
effort
on hold (I am back in the hospital as we "converse")
Vance

Sorry to hear that Vance. Do you need anything?

Paul Lamar ...No rotor no motor.

My buddie Lary David has been suplyin me with reading materials, And it
looks like ny white blood cell
count is finally rebounding - I may get out by the week end.

With the Bellvilles, we are leaning toward a 2 stack in series to get
displacement. Bellvilles do not like to
stay centered without help so a suggested assy would be flat steel against
alum crush plate, Bellville "peak"
to the flat steel, Bellville OD's to a large steel flat washer, and the
second Bellville peak to the bolt head
with  probably anothe small flat washer to ease bolt turning.( no scanner
hear so I cannot sketch)
Vance

Use MS Paint Vance.

Paul Lamar ...No rotor no motor.

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