Paul,

Are the Barry mounts the same units as those used on tracitional aircraft
motor mounts?

Joe Berki

No but they are made by the same company out of the same material and they

are

one tenth the cost of aircraft mounts. They are used on the Questair

Venture as

well as a dozen or so rotary powered aircraft.

Paul Lamar

Paul,
I remeber you telling me about this before and turned my mounts 90 degrees.
At that time I told Charlie about the loads but he thought that the mount
were different..  Attached are the mounts that Charlie and I are using.

Joe Berki


What brand are these? Do you have any load or deflection data?
Dwgs of how they are installed?

That is all important and why we use these $5.95 Barry mounts as they publish
load and deflection data on them.

Not to say yours won't work.

Paul Lamar

Paul, these appear to be standard Lycoming Dynofocal mount pieces.
Steve Beckham.

Ah so! Thanks Steve. In that case they are being misused because the
softest direction is the same as the Barry mounts. Namely axial and not radial.
In an out and not side to side. Lycomings vibrate up and down and side to side
as well as torsionally. Dynafocal mounts focus on the CG of the engine
for up and down and side to side vibrations typical of horizontal opposed
piston engines. The rotary has zero vibrations in those directions so those
mounts still need to be rotated 90 degrees. They are now focused at infinity fore and aft. They are also too hard for the rotary loads.

This is not to mention the cheapest Barry versions of dynafocals  for the Skyhawk cost $75 in the wicks catalog. The Barry 2202 industrial mount does exactly the same thing made out of the exactly the same material and cost six dollars :) Jim Griswold who designed the Questair Venture knew exactly what he was doing as he also designed the Piper Malibu.

http://www.rotaryeng.net/motor.html

Of course anything or nothing will work. Perry has been flying his Long EZ with the rotary engine bolted solidly to the airframe for 15 years. He had no other choice in the years he used a ducted fan. The rotary is that smooth.

Paul Lamar