Message-ID: <009801bf91fa$fb803c40$e0eafea9@peweston>
From: "Pat Weston" <peweston@teleport.com>
To: <lancair.list@olsusa.com>,
	"Bob Foxwell" <bfoxwell@isd.net>
Subject: Re: counterweight rudder
Date: Sun, 19 Mar 2000 14:24:30 -0800
Mime-Version: 1.0

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Bob,

I've done my ailerons and elevators, yet to do the rudder on my ES, coming
up soon though. I spent way too much time and money looking for the best
counterweight solution. I wanted to have as dense a material as possible to
have a lower net weight and also something easy to work.

I first used the lead that came with the kit and "having fun" (per the
manual) pounding it with a hammer yielded less than desirable results. It
was very difficult to have a reasonable looking result that allowed all the
travel required for the aileron.

I then followed the lead shot cast in epoxy path, this was easy to work but
the density was very poor. An SG 0f 6.3 compared 11 of lead.

My next path was to add tungsten powder to the above mixture, the idea was
that the tungsten would fill the gaps between the lead spheres and improve
the SG. Some of the tungsten did indeed stay between the spheres but the
majority sank to the bottom and the lead shot "floated" on top of it. The
result was an SG 8.5, probably acceptable. But it is near impossible to work
once it has cured. It cut through sandpaper like a hot knife through butter
(a reverse analogy, sorry) also wore out my tungsten tools with little
impact to the material.

I finally settled on building a wooden mold, melted shot on my kitchen (gas)
stove (while my wife was in, would you believe. Yet another testament to her
long suffering.) in and old baked beans tin. Poured the lead into the mold,
let it set, shaved out the undulations, roughened it up with 40 grit, bonded
it to the aileron, wrapped 2 BID around it, Presto Chango, a perfectly
dense, workable and good looking solution.

The weight was attached toward the forward end of the arm on the aileron. I
cut a piece of foam and set in between the weight and the forward curved
part of the aileron with a loose micro mix. I did this on both sides as
there were weights on both sides (top and bottom). I then wrapped the 2 BID
cloth around that. The point was to make a rigid structure to prevent the
weight from vibrating at the end of the arm.

The lead was very easy to work with an open rasp. That is a rasp that has
openings on the cutting surface. Cost about $5 at Home Depot, you local
aeroparts store.

Please refer to my web site ( http://www.teleport.com/~peweston ) for any
details of this that I may have forgotten here.

Someone on LML mentioned that they used solid tungsten rods. This would be
the best of all, if the rods are affordable. 10 pounds of Tungsten powder
cost me over $100.00.

Keep on Sandin'

Pat
"Only three short years to go!"
http://www.teleport.com/~peweston


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