Hi rotaryeng

Can someone please assist with a technical question regarding a RX8
4 port low power manual engine 190 bhp engine will be used in
helicopter.

We would like to find out what the rotational inertia is so a damper
can be designed for the pulsation

Also can someone clue me up regarding the purchase of aluminium end
plates, where to purchase and what should the cost be,

Would very much appreciate your assistance

Kind regards George



Kind Regards George Crooks


I have no idea on the rotational inertia but here is a coupling
design that has evolved from years of experience.

Aluminum end plates are available from Racing Beat.

http://www.racingbeat.com/RX7-1993-1995/Rotor-Intermediate-Housings.html



They are peripheral exhaust and do not use the RX8 side exhaust.
In that case you might as well sell the 4 port RX8 engine and buy a
3rd gen RX7 engine and base it on those rotor housings, e-shaft and
rotors.

I recommend p-port intake as well. In that case you will have 250 HP
to work with at 7500 RPM.


Paul Lamar

--

George, If you have a 3D program I can send you an IGES of the
coupler.

Paul Lamar

I was told by a relative, working in the aeronautical engineering
field, that helicopters are highly complex and extremely difficult to
design, and the people that are known for being able to design a
working helicopter are very few, and known to everybody in the
industry.

A French engineer having proven his expertise in helicopter design
had an argument with his employer, in certain businesses, nobody
would hire you if you leave another company in the field, as this may
result in transmitting know-how, patents and other industrial secrets
to competitors, and when the Spanish govt knew this, it was in the
60's, they hired that expert who built several models of helicopters,
if I remember well, under the mark 'AISA', for Industrial Aeronautics
in Spanish.

Around 1986, I made a car trip for reasons of work from Madrid to
Oviedo (Asturias) and while passing next to a wreckage-recycling
lot, I saw one of these  helicopters standing among the many cars
there.

I ignore completely the final destination of this piece, and as
roads changed since then, it would be extremely difficult finding the
place again, but a similar thing seems having happened with at least
one of the prototypes of Wankel powered Corvettes, that was bought by
a British writer when it was about to be put into pieces, and is
shown in local Wankel lover's meetings, but never making the engine
run, previously, two GM Wankel powered Corvettes were at exhibition
in the Ford's Dearborn Museum in Detroit, at least, it were there in
March 1988.

I read somebody stating that these Wankel Powered Corvettes, one with
two, and the other with four rotors, won't be allowed today going on
roads or streets, as none of two met the rules about headlights.


Regards. Salut †

Jose Gros-Aymerich Madrid, Spain



Hello Jose Gros-Aymerich,
and all who may be interested

I trust my mail finds you well in health and in good spirits


There are monuments of all kind in backyards all over the world, it goes
without saying that if I fail to plan properly then it can be said that I
have planned to fail.

With that said there is a poem that suits the situation it is called "the
bridge builder" available on the internet and worth a read if you like
simple wisdom, if not and only here for self

benefit, my suggestion is don't bother



Projects fail for all sorts of reasons and I accept your comments as very
valid and as you might notice that failure happens to companies much,
much
larger than my self



I am seeking information and contacts; there are a number of independent
aeronautical engineers over the world that have experience a variety of
areas, the helicopter I am building is a Scorpion 2 seater  for which
having
been of 1970s technology it was a good helicopter with many being
built from
kits and for sale on the internet today, they started out with an
outboard
boat engine  and grew from there , there are only just a few modification
that I intend to carry out which is engine and rotor.



Right up to today popular helicopters have the power of the engine
transmitted through V belts, which have failed in the past and who know
about the future.



The Scorpion has V belts driving both the main rotor and the tail
rotor; I
plan to make the aircraft safer by employing much safer means of
driving the
rotors, and more pilot friendly.



The engineer that I am working with or will be in January will be
designing
the reduction box for the helicopter , he has done this previously for a
helicopter fitted with a diesel engine,  he has advised me to change the
main rotor system to one which is pilot operator friendly,

which is a fully articulated system, he has also successfully deigned a
fully articulated system previously so thus my enquirys about the
rotational
inertia of the Mazda  rotary engine and again regarding the one rotor
turbo.

I have met a man who trades under the name Billet INC, (he has a website)
who builds some lovely rotary stuff a little expensive for me, but good
stuff; he is a Drag Racer and builds for that industry. His rotary
engines
hold world records and as a hands on motor mechanic for many years I can
appreciate his work. He suggested that I take a look at the single rotor
rotary saying he could build a turbo engine and get 200hp out of one
rotor,
most twin rotors can obtain 400hp according to the Internet and apart
from
the engine I saw on the rotaryeng  site I have not located another and at
Paul's suggestion I have e-mailed Richard Sohn hoping he might answer
some
questions for me.

The intent of my story is to obtain options that I can consider ,
possibly
split the engineering process between one or more qualified people and
then
bring the project together  under the most appropriate person to do the
final stress calculations balancing , ground resonance effects and the
engine rotor resonance , if someone knows the rotational inertia it will
save me possibly pulling an engine apart to measure everything
depending on
the decisions I make which will have to be made by January to fit in
with my
current planning . I am open to constructive criticism and advice so feel
free to make comment wherever it might be helpful or beneficial to the
project, just like the “bridge builder” it is not just for me but for the
people who come behind.

Kind regards

And best wishes

George

  Hi George!: you've been very kind in your response to my note, but I
missed
completely the facts, it's not you designing an helicopter from zero
yourself and
alone, but building an already proven project; as the goal in my comment
was
making some mild mental pressure towards consulting experts, and taking the
things slowly and with lots of wisdom, you've show you're already doing
this by
your response, thus, I just want pointing that I offer you my best
wishes for
success in constructing and flying a homebuilt helicopter.

By the way: the Spanish prototypes I cited, all them flew successfully,
just the
whole program was discontinued because budgetary reasons, equal as the
British politician Shackleton? send to wreckage the TSR2, or something
like,
supersonic bomber airplane project. Salut

Jose Gros-Aymerich Madrid, Spain