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Date: Tue, 12 Sep 2006 14:24:27 -0400
From: Ernest Christley <echristley@nc.rr.com>
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To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: It runs!
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Todd Bartrim wrote:

> I've always considered that I've got a pretty high risk tolerance 
> (bullriding, etc.), but this is one that I wouldn't touch. Too high of 
> risk with too little payback. I believe the timber would be plenty 
> strong enough if you could ensure balance, but this is not likely. 
> Odd's are that it would be out of balance which would contribute to 
> it's demise. Even if it did hold together, I hate to thing about the 
> loads it would be imposing on bearings in your PSRU & engine. It's a 
> sh***y job as it is to stand next to a 4000 rpm spinning prop while 
> setting your static timing. I wouldn't want the engine being shaken 
> apart while I was doing it. Sure you could get your fence post 
> balanced, but why? It's probably less effort to find a prop, even if 
> it's not the one you'd want to fly with.
>
Todd, you can put together the balancing apparatus with stuff from your 
junk-bin.  A foot of drill rod and two feet of steel angle.  A post-it 
note will serve nicely to help you dial in a perfect balance.  It would 
take an hour or two in the garage to get the balance perfected, and then 
the static test would be a little less sh***y once you remove the 30mph 
wind from your face.

People who don't build airplanes think I'm crazy for building an airplane.
People who build airplanes think I'm crazy for building a plans built, 
delta wing.
Everyone else thinks I'm crazy for carving a propeller.

Don't worry, guys.  I won't be using a fence post for a test club.  I'll 
use the blank that will become my prop.  A fence post would make a 
horrible propeller blank.  It's very hard to control the warp when 
carving thick wood sections, a major reason for building props from 
laminated blanks.

-- 
         ,|"|"|,              Ernest Christley       |
----===<{{(oQo)}}>===----    Dyke Delta Builder      |
        o|  d  |o        http://ernest.isa-geek.org  |