I have a Raven redrive on a 1.3L 16 valve Metro/Suzuki engine.  A thrust
 test of this design by another Raven customer reportadly achieved over
 440 lbs of thrust near sea level with a 70"+ Powerfin prop.  Raven
 developed this drive to survive on the 1L (3 cyl) with 3 blade props.
 The harmonics were tearing things up until rubber bushings were added in
 a "cushion hub" design.  The newest design does not use an outer bearing
 on the crank.

 Tracy Crook also uses rubber bushings to smooth out the hard power
 pulses of the rotary engine.

 These harmonics could also be the source of the problems with drive belt
 on the mechanical fuel injection.

 Dan



 The outer bearing has nothing to do with the power pulses.
 It is strictly there to mitigate the rotating bending loads
 on the crank that lead to fatigue cracks. Leaving the bearing
 off is a big mistake.

 The torque isolators are there to extend the life of the belt.

 ------------------------------------------
 BTW going on static thrust alone is also a big mistake.
 If you optimize the prop pitch for max static thrust you could run out of
 RPM and thrust at takeoff and climb out speeds. We had a guy die doing
 that. Ironically with a Suzuki engine. The canard could not climb out of ground
 effect and hit a tree.

 What you want is max trust at 60 MPH or there abouts.



 Paul Lamar ...No rotor no motor.

<PREECHY>
And..  You want to start your test flying at an airport with a long
enough runway that you can easily accel to your best climb speed, and
still have plenty of room to abort.  That way if you are having any
issues you can put it back on the ground and rethink/readjust things a
bit.  Moving to a field with a longer runway might take some
inconvenient relocation of airplanes and equipment, more driving, more
money, and more time, but in the end, it can limit your risk and avoid
getting you into the newspapers.  Your engine isn't like anybody
else's and despite your best hopes, it might crap out at a bad time.
Operating from anything but a long runway increases risk.

Burt Rutan proposed testing from a runway long enough to support
taking off and landing straight ahead the first few times - not
climbing above about ten feet (no further than you'd like to fall).
It's quite workable even in a high wing loading airplane like a
Varieze.  My first few flights in that bird didn't get above about
five feet.  No damage.

</PREECHY>


Matt-


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