I am working on the design of the carbon fiber six inch diameter tube spar.

The spar is the heaviest part of the aircraft structure so it pays
to make it out of expensive carbon. The skins of course can be glass
or carbon depending how much money you want to spend.


Paul Lamar

Paul,
I am sure you are aware of the method that Paul McCready used to make the
carbon fiber spars for the Gossemer Albatross:

He used Aluminum irrigation tubing (~3-4" D) and laid the carbon fiber up on
the tubing, then dissolved the Aluminum out with KOH.
Bill Schertz

I was called in as an aerodynamic consultant on the one that eventually won the
Kremer prize by Jack Lambie round about 1976 or 1977. My girl friend Rhonda and I drove up
to the valley to have a look. I was surprise to see a propeller about 4 or 5 feet in diameter
made from two model airplane wings and wire braced. I suggested a larger diameter prop
not wire braced and further geared down. They did that and went on to win the $50,000 prize :-)

I was not aware he built the spar that way. I was thinking of using a metal or plastic
tube covered with several layers of garbage bag or other thin plastic material cut in long strips.
After the epoxy is cured the spar can be slipped off the tube. I have done that
many times on shorter composite tubes. Sometimes the strips can just be pulled
out from between the surfaces. That gives enough clearance to remove the
spar from the tube.

How's the Kiss Cruiser doing? Do you like living up  there in the US bush? :-)

Paul Lamar

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The Rotary Engine free News Letter. Powered by Linux. If you want off
the list PLEASE let me know and I will remove  you.  ACRE NL web
site. http://www.rotaryeng.net You Tube http://tinyurl.com/beqqxas
Copyright 1998-2016 All world wide rights reserved.