Hi Paul,

I would be very interested in finding out the result of Will's mission to
Mistral.  This is my largest concern with the idea of using a rotary
engine.  To me, 10K for a competent purpose built PSRU with a 2000 hr tbo
that I don't have to worry about is worth it.

Kent Baxter

Don't hold your breath. I doubt Mistral  have the money to build anything
let alone one gear box. They won't be around to give you service anyway.

BTW It is the communist system of new product development:)
The poor dumb tax payers put up the venture capital :)

Tracy's box is OK. It has 15 years of use and development
with thousands of hours of accumulated use on dozens of airplanes.

Apparently it only has one problem and I think we have that
identified and solved. The problem was subtle and only showed up
on less than a half dozen gear boxes. Pins were being sheared.
Flex plates were being destroyed. Planet ring gear bolts sheared.
You run the stress numbers and the parts LOOK strong enough on the face
of it. The other hundred gear boxes are working OK.

The answer was Tracy's rubber bushings were not working as
rubber bushings. It was only recently that I figured that out.
It was an easy mistake for Tracy to make. It looked OK to
me 15 years OK. It wasn't until all these strange things
began to happen in the last few years.

There is no guarantee the same thing won't
happen to the Mistral gear box. Relatively speaking it has zero
hours compared to Tracy's design.

The new rubber coupling can be retrofitted. I feel confident
that will solve the torsional vibration problem. It is also tunable
in the sense the rubber bushings can be easily changed. The design
is used on just about every motorcycle rear wheel made. We are not
reinventing the wheel here. Pardon the pun :)

It was also widely used on Suburu belt drives and for the same reason.

Paul Lamar


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