Paul,

On a previous post, I think you said that 20B engines are getting
scarce and expensive.  What is unique about them besides the crank?
Can you build a three rotor with 13B parts if you have a crank made?  I
noticed that Racing Beat offers a unique 20B end piece made out of
aluminum.  I think a three-rotor with aluminum end and intermediate
housings would be ideal for this helicopter:
 http://www.vertical-aviation.com/

By the way, did you get a chance to go through that website on the
Cessna CH-1 helicopter?  It uses an engine installation that would make
an automotive based engine simple to install and it has a very elegantly
simple rotor head.

Steve Brazil

Please don't send html messages. It screws things up down the road.

The 3 rotor intermediate housing is unique as well as the shaft.
The Aussie have a special 3 rotor shaft and center main bearings
so 13B intermediate housings can be used to build 3 or four rotor
engines. You can also buy a 3 rotor from Mistral as they are making
all the parts.

I read the site but I saw little on the rotor head or dwgs of the rotor
head.

-- 
Paul Lamar ...No rotor no motor.

What is that "Aussie" company?  Most of what I see about Mistral is that
their stuff is very pricey.

On that CH-1 website, the end of the piece has a flight report as well as
exploded diagrams of the rotor head and control mechanism.  It is a
teetering, free coning type but it is not underslung.  It uses bent-up
L-sections made of stainless sheet metal; there are no feathering bearings.
Very clever.

I think their web sites are down right at the moment.
http://www.xtremerotaries.com/
http://www.gurumotorsports.com/


Yes I saw that dwg but I did not understand it at first. Are they twisting
that bent up sheet metal to change the pitch? Scary.

Too bad there are no good pictures of the rotor head.

Paul Lamar ...No rotor no motor.

The Rotary Engine NewsLetter. Powered by Linux.
ACRE NL web site. http://www.rotaryeng.net
Copyright 1998-2006 All world wide rights reserved.