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Date: Fri, 08 Jun 2007 22:24:56 -0400
From: cbeazley <cbeazley@innovista.net>
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To:  flyrotary@lancaironline.net
Subject: Re: Single rotor video
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> Greetings,
>  
> I shot some more video today, of the original shore 60 damper, and then of the new shore 50 damper.  The 50 was noticeably better, particularly in that it completely eliminates a severe resonance that was happening at 2700 rpm.  With the 60 shore, at 2700, there was a very audible "rattle", and the air filter shook so hard it was a blur.   My guess is that the shore 50 moved it from 2700 to somewhere below the 2500 I'm using as a minimum. 
>  
> I'm sort of dazed from looking at video, but the prop flex is certainly not gone.  It's a bit cleaner with the 50 shore, but not by a huge amount.  The worst flex is between 2500 and 3000 rpm, and that's also the point where the trailer rocks from the force of the prop.  It's quite likely that's at least contributing to the problem, but there's no denying that the torque direction, and prop flex direction are coupled together.  
>  
> I can already think of lots more tests, but the 50 shore damper stays, and I wish they made a softer one.  I also think anything over 3000 rpm is not a problem, and this might be a limitation that could be lived with.  I've got about 16 hours of driving in the next few days, so I'll have plenty of time to think of what to do next.  
>  
> Rusty (a bit more optimistic today)

Hi Rusty;

Wild!
I think Lynn is correct.
Even a few pounds at the radius of a normal starter ring gear (as a flywheel) should make a 
noticeable difference.
My guess is that the forward and backward tip motion is mostly due to the positive/negative thrust 
as the blades transition from forward motion to slowed/stopped/reversed by torque reversals.
Adjusting the blades to near zero angle should confirm it.

(Glad I'm not in the plane of those blades with the camera:)
Play Safe!
Cary