Tractor Gyro

[Scorpion]

My unfinished model of our composite single seat tractor Gyro.

I've put the Pix up for comments and I'm sure there will be a flood of them, but thats what we're all here for, right.

Thanks Fella's

Graeme

[niquenaque]

scorpion,

Dolphins eh?

Looks sharp, but..

Where does the engine sit?
where is the mast?
Where is the suspension?
What is the square meterage on the hull?
How much does it weigh with a 20 oz / ft lay up + resin?
What power plant are you going to select?
How is it going to be cooled?
Where are the air intakes for cooling?
How are you transfering power to the prop?
What will the MTOW be?

Interested to see...

Cheers,

Nic.

[Scorpion]

Nic,

I did say "Unfinished Model".

Engine is behind the pilot. Yes, the carbon fibre shaft runs in a protected kevlar tunnel between the pilots legs.

Mast will be about inline with the leading edge of the stub wings

Suspension, landing gear is retractable, main gear retracts inward from the end of the wing stubs into the fuselage, nose gear retracts back into the fairing underneath back from the prop.

Overall length is 3.6m, cockpit width is .7m and .9m high

Empty weight will be around 170kg

Engine is an 80hp 2 stroke, water cooled.

Radiator is in the scoop below the fuselage, inline with the stub wings.

Fuel is in the stub wings.

MTOW will be around 320kg

These spec's are approximate.

[Scorpion]

Nic,

I added on the some parts so you can see where they go.

[splashdown]

Hey Scorpion. Nice model! looks a bit like some of my scribbles.
What did you make it out of?

As to the the design...

Just make it a pusher and save some weight and complexity. It looks like you have plenty of room if you have the HS running between the verticals (and not the main body).

Another comment is although I really like the dropped outside HS fins, they make the whole airframe much wider and may impact your ground transportation options. Not sure how much space will be left in the stub wings for fuel after you retract your mains, but its a clever way to separate the fuel from the pilot (I'm presuming a firewall behind the pilot). I would also have the nose gear as far forward as you can. I believe the bigger you make the main-gear-nose-gear triangle the more stable you will be. It will also reduce nose-wheel sensitivity by being on a longer moment arm.

Have you seen the attached computer model from the French site? (A bit nose-down for my liking).


Pretty cool though! Keep posting the pics as you go.

[Scorpion]

Hi Splashdown,

Yes I had seen the Gizio computer model before, that's what prompted me to pull out my design I was working on a couple of years ago and start making it.

Comments noted, but it's still going to be a pusher.

Stablizers that protrude out past the booms are detachable for transport.

Scorpion

[Scorpion]

Hi Splashdown,

Oops, boo boo. Wrong info on last thread.

It's still going to be a tractor Gyro!

Scorpion

[niquenaque]

Engine is behind the pilot. Yes, the carbon fibre shaft runs in a protected kevlar tunnel between the pilots legs.

Ah, the same arrangement as a powered glider that I know of, name is the "Stemme".

How are you coupling the shaft to the engine? Bearing in mind that Carbon Fibre composites have a 1% deflection to break whereas fibreglass has a 5% deflection to break - is there some sort of an elastomeric coupling to spare the shaft from some of the engine / gearbox vibrations?
[If I had a big shaft between my legs I might be a happy man, but not if it weren't my own and especially if it were doing 2400 revs and flopping around excitedly.. I'd be as worried as a choir boy at mass..]
What about the gear box - how will it be connected?
How are you mounting the engine and what on? Does it fix into the composite hull or is it on a chassis and what we see is merely shrouding?
How is the engine going to be accessed for maintenance and prefilghts?
How do you check the oil, water, fuel, end play on the drive shafts, slop in the bearings, etc, etc...
How are the control links going to be accessed for maintenance and preflights?
How is the rotor to be started - does it have a pre-rotator? Brake?
At 340 MTOW I think it a little ambitious in terms of the actual mass you will end up with after retracting gear is added into the fray - how is it to be raised and lowered? What happens when the mechanism breaks and you can't use the button on the dash to do it - do you crank it down? How is it locked into postion? - I've seen many an 'end over centre' lock fail when least expected.

Heaps of q's to answer, but I don't expect you to post them, just think of the likely implications while you are modelling, once you step into making the real mccoy, you start to blow big $ for nothing if it is wrong.

Hope this helps,

Nic.

[Scorpion]

Hi Nic,

I'd have thought that you would have sorted out all the questions you are asking about my design when you were designing your Stemme design using shaft drive between your legs.

Stemme is very nice, why haven't you proceeded with it.

The front half of your Stemme looks very similar to my design I posted in June 2006, the Scorpion Tractor Gyro.http://www.rotorcraft.com.au/attachments/gyro-chat/755d1186440464t-tractor-gyro-aus-scorpion-tractor-gyro-7-jpg (http://www.rotorcraft.com.au/attachments/gyro-chat/755d1185984987-tractor-gyro-aus-scorpion-tractor-gyro-7-jpg)

All the specifications I have listed for the Gyro are achievable thanks to ultramodern metals and exotic composites. The proof will be in the finished Gyro later this year.

Watch this space!

Scorpion

[Mitch]

G'Day Scorpion,

Great looking tractor gyroplane:) I wish you every success. It looks well thought out and 'slippery'.

Could you explain your reasoning for the 'down swept' external HS sections?

80 HP two stroke....what brand of engine?

I look forward to seeing this Tractor flying successfully. All the very best.;)

Mitch.

[SamL]

Have you seen the attached computer model from the French site? (A bit nose-down for my liking).


Pretty cool though! Keep posting the pics as you go.

This machines CofG and the positioning of the undercarrage would mean easy rollover and require a very strong front undercarraige assembly.
Also rotation during take off would be impossible.

Sam....

[Scorpion]

Hi Sam,

Are your comments for my model or the computer pix from "Splashdown" ?????

Graeme

[splashdown]

Sam is refering to the french computer model. With the mains so far aft, there is a much larger amount of weight on the nose gear.

The main gear position also means you couldn't rotate (nose wheel up but still on the mains), because you would essentially be flying at that point.

[SamL]

Thats right Splashdown.:)
Another thing I prefer with gyro's is a fully immerssed (in prop wash) rudder & fin assembly. This aids in low speed flight and cross wind landings.
Keep in mind what happens after air is pushed through the prop ?????

Sam....

[Scorpion]

Hi Mitch,

The reason for the downward angle of the HS is because I wanted to keep the support attachment to the fuselage in line with the prop and body centre line. Because the booms are dropped lower to give us the shorter landing gear we just followed the line through the end of the boom.

This also gets the VS's lower to clear the rotor.

The engine is a new BhA700, this is a 2 stroke 2 cylinder 701cc 80hp engine, which I will let you all know about later.

Graeme

[Mitch]

Thanks Graeme,

Again, every success with this mate it sure looks the goods. Cant wait to see how the composites finish up and how she performs with said engine package. Bloody good stuff!:D:D:D

Mitch.