X-Mozilla-Keys:                                                                                 
Gary Casey wrote:

I finally feel the urge to respond to the flurry of interest in "remote" engine
mount isolators.  One necessary function of the isolator is to eliminate the high
frequency vibrations the engine produces from the rest of the structure.  If a
large structure is bolted directly to the engine it must be sufficiently stiff so
that the natural frequency of the structure is higher than the highest vibration
frequency the engine produces(for example, at 6,000 rpm the rotational exitation
frequency is 200 herz).  I would think that to impart this degree of stiffness
would require a very massive structure and that is one of the primary reasons why
engine mounts are always placed as close to the engine structure as possible.

Gary Casey

Very good points Gary.

I hear you and have given a little bit of thought to that subject.
That is one of the reasons I specified 3/4 inch diameter  0.049 tubing
rather than
smaller tubing that would do the job with the shorter pieces. One thing
about 
the rotary however and that is; it is smooooth. If we find a tube that
is
resonating in bending  we can add mass or stiffen it as required.
Are you listening Romulo? :-)

As I said at the start of this project... this is experimental.
IMHO If it can be made to work it is a minor breakthrough in the
mounting
of rotary engines in composite airplanes because IMHO it gets the loads 
into the composite structures better than bolted joints would.

Piston engines would be a whole nother matter.

Paul Lamar
 
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