I am building a tractor, side by side, engine behind pilot gyroplane.

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Sabine

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Firstly, Margie, thanks so much for fixing my glitch and enabling me to join your forum.
I have for the last 10 years, when time has permitted and when I have been near my workshop, been developing a side by side tractor gyroplane. Sadly I have now had to put it on hold and seek work in the UK. I live/lived in South Africa. I guess there are reasons for everything and being away from my project is also a great time to think, ponder and research. When I started out on the project, I employed an aeronautical engineer and he based all of his design criteria on BCAR T (British civil aviation authority) who have a weight limit (all up 2 pax and full fuel of 600kgs). We started with a Subaru EJ20T- the weight 104kgs barebones and the boxer configuration make the placement of fuel tanks veryIMG_1733.JPGIMG_1736.JPGIMG_1743.JPG complicated and so am now looking for an engine/redrive of sub 100kgs. So far I am seriously leaning towards a Mercury 2 stroke fuel and oil injected powerhead which certainly looks very positive. The next unknown is the long carbon fiber prop-shaft (1500mm+-) to the propeller that goes through a kevlar tunnel in the cockpit. It would seem that torsional vibration has historically been a problem here. Molt Taylor and others rectified this using a Flexidyne coupling and my thoughts are, surely today there is something out there that is lighter and possibly better (motorcycle slipper clutch?). I really would appreciate your thoughts on these. I enclose a couple of pics for your perusal. Kindly Sabine.
 

Geraldc

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I was reading about carbon fibre driveshafts and one of their benefits is soaking up torsional vibration. As well as 2 Giubo couplings would
there be a need for any other damping?
Question for the experts here.
 

saini flyer

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Firstly, Margie, thanks so much for fixing my glitch and enabling me to join your forum.
I have for the last 10 years, when time has permitted and when I have been near my workshop, been developing a side by side tractor gyroplane. Sadly I have now had to put it on hold and seek work in the UK. I live/lived in South Africa. I guess there are reasons for everything and being away from my project is also a great time to think, ponder and research. When I started out on the project, I employed an aeronautical engineer and he based all of his design criteria on BCAR T (British civil aviation authority) who have a weight limit (all up 2 pax and full fuel of 600kgs). We started with a Subaru EJ20T- the weight 104kgs barebones and the boxer configuration make the placement of fuel tanks veryView attachment 95468View attachment 95469View attachment 95470 complicated and so am now looking for an engine/redrive of sub 100kgs. So far I am seriously leaning towards a Mercury 2 stroke fuel and oil injected powerhead which certainly looks very positive. The next unknown is the long carbon fiber prop-shaft (1500mm+-) to the propeller that goes through a kevlar tunnel in the cockpit. It would seem that torsional vibration has historically been a problem here. Molt Taylor and others rectified this using a Flexidyne coupling and my thoughts are, surely today there is something out there that is lighter and possibly better (motorcycle slipper clutch?). I really would appreciate your thoughts on these. I enclose a couple of pics for your perusal. Kindly Sabine.
Very interesting. I cant add to the TV input but wish you success. Your vertical tail suggests a very long mast. Why not just flip it 180degrees as you have such a tall stance?
 

Topaz

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Wow. Interestingly different "take" on this type of aircraft. Best of luck to you on your job search, I hope you're soon able to resume work on your project, and welcome to the forums! :)
 

BBerson

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Look at the Stemme S-10 driveline for ideas.
I would think the Flexidyne housing may be heavy, but the engine needs a flywheel anyway and the housing might substitute somewhat for a flywheel.
 

Sabine

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Very interesting. I cant add to the TV input but wish you success. Your vertical tail suggests a very long mast. Why not just flip it 180degrees as you have such a tall stance?
Thanks for your comments- always appreciated. The mast is approximately 1200mm above the fuselage and the rotor won't contact the tail. I will be shortening the rather silly looking tailwheel- I don't like it and it was originally an attempt to put more load onto the mains.
 

Sabine

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Look at the Stemme S-10 driveline for ideas.
I would think the Flexidyne housing may be heavy, but the engine needs a flywheel anyway and the housing might substitute somewhat for a flywheel.
thanks for the lead- one of the greats of the outboard powerhead is the very small size of the flywheel, which will be on the other end of the crankshaft to the output.
 

Sabine

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Wow. Interestingly different "take" on this type of aircraft. Best of luck to you on your job search, I hope you're soon able to resume work on your project, and welcome to the forums! :)
thanks so much
 

Sabine

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Mar 31, 2020
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I was reading about carbon fibre driveshafts and one of their benefits is soaking up torsional vibration. As well as 2 Giubo couplings would
there be a need for any other damping?
Question for the experts here.
your response is greatly appreciated- yes the 80mm dia filament wound shaft will be very stiff- if Guibo couplings would do the trick I don't know. The trick seems to be allowing the engine to start first, hopefully keeping the TV out of the operating range of the engine and prop.
 

rotax618

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I have a Nissan 350Z which has a carbon fibre tailshaft, perhaps you could look at adapting one of these, the later 370Z also has a carbon tailshaft.
 

Sabine

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I have a Nissan 350Z which has a carbon fibre tailshaft, perhaps you could look at adapting one of these, the later 370Z also has a carbon tailshaft.
I had the bespoke carbon shaft made up for me. It is filament wound as per several racing car / supercar manufacturers and balanced afterwards.
 

galapoola

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The Bell P-39 Airacobra has a similar layout, have you looked at how they did it?
 

Sockmonkey

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Thanks for your comments- always appreciated. The mast is approximately 1200mm above the fuselage and the rotor won't contact the tail. I will be shortening the rather silly looking tailwheel- I don't like it and it was originally an attempt to put more load onto the mains.
As that's going to raise the cockpit a little, I suspect you're gonna want to add a step on your main gear legs for easier entry, and so you don't bruise a thigh on the lower door lip when getting in.
 

Toobuilder

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Wondering what requirements drove the trade study to favor such a complex powerplant configuration? Why not just hang the tractor engine off the front, or make it a pusher?
 

GeeZee

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Here’s an old thread you might find interesting.
 

Sabine

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As that's going to raise the cockpit a little, I suspect you're gonna want to add a step on your main gear legs for easier entry, and so you don't bruise a thigh on the lower door lip when getting in.
At the moment its quite easy to step onto the wheel and in and mindboggling if she wears a mini
 

Blackhawk

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Hi Sabine,

You have done an excellent job on your tractor gyro, what HP are you looking at using.

Your design is very much like my design from 2002; which I never got around to build.

Scorpion Tractor Gyro.jpg
 

Geraldc

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That looks like a candidate for the D-Motor.It is compact water cooled and direct drive.
 
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