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Date: Tue, 04 Dec 2007 17:39:19 -0500
From: Ernest Christley <echristley@nc.rr.com>
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To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: Giving up on single rotor
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Thomas Jakits wrote:
> Lynn, Bill, George, Richard - anyone knows what I am talking about? Any
> possible application for the 1-rotor?
> Am I full of it??
>   

This is one of many methods of dealing with torque reversals.  In this 
case is the idea that you do no pull backwards on the load.  You let the 
load fly ahead forward on its own.

The problem with this method is there isn any backpressure on the crank 
when the next cylinder fires.  The crank flies ahead and slams into the 
load.  I believe this makes the problem worse in most cases.

Al's method is the best way, as I see it.  An engine drives a load 
around a circle with a series of hammer pulses.  The object is to couple 
those hammer blows to the load with just enough spring that the blows 
even out to one long push.  The amount of spring needed relies on the 
rotational moment of the load, the spring's constant, and the spring's 
torque arm.  The rotational moment is static for a given propeller, and 
the constant and torque arm for the spring are nicely summed with a 
torque wrench.  A complete model would require measuring the amplitude 
and frequency of the hammer blows, but a graph built from a few 
experiments like Rusty conducted will allow one to plot where the system 
resonates and home in on an appropriate amount of spring.