Microlighters

Check this out! This is pretty cool!
http://www.youtube.com/watch?v=3RPYWmdv ... re=related

Plenty Horse Power required but very impressive.

Kind regards,

Gunter Rostek.

If memory serves me correct then these guys also plan to develop a jump take off gyro.

Looks darn good!

http://www.cartercopters.com/

It is a really cool video. It says on the side that the pilot built it himself!! Imagine doing that jump take off and the pride when yoy know you devolped and built it!!
THI: That thing look great!
Now.... who wants to develop a jump-takeoff system for trikes?

Suddenly gyro's "jump" up in my list of "wanna try"

My take on this: The secret of this specific one is a seeerious prerotator with a mild jump. This is more a take-off than a jump. You can see when it is in the air, it just keeps climbing without even lowering the nose to get airspeed. Nice concept.

I've seen other videos on youtube, where the suspension is seriously compressed and then a sudden release gets the gyro in the air, but then the nose is lowered to get speed for the flight. Also needs some good prerotating to almost flying speed.

From the ROTARY FLYING HANDBOOK, for jump take-off you need the ability to prerotate the rotor system to speeds approximately 50% higher that those required for normal flight (page 20-5)

Eish...

RV4ker wrote:Suddenly gyro's "jump" up in my list of "wanna try"

I know what you mean!!!
Low Level and THI: Tell us more!

I have been thinking about a hydraulic drive for the pre rotation on Gyros since the first time I saw a Gyrocopter.the drive must be a one way drive that will free run once in flight ,then the hydraulics can be disengaged.Good idea ,but we need someone to develop and build one .

Interesting that you mention it. Johan from Wagtail has gone down that development route with the hydraulics. really an incredible system. I have looked over their shoulders during a routine 1200 hour rebuild of one of the machines....the only thing which needed replacement on the whole pre-rotator system was the tooth belt....the hydroulics is incredibly smooth and reliable.

On the topic of jump take off...I have asked the question lots of times and everytime Johan keeps telling me the same thing...LOTS of Hp, only real way is through shafts, hydraulics will just be way too heavy.

Some interesting facts which Johan pointed out was the balance of power to the prop and to the rotor during such high energy pre-rotation......as you ref up the engine to increase the speed of the rotor you also speed up the prop and then the prop absorbs more energy...the end result is that you need a really powerfull motor to accomodate both energy users, or you need some clever uncoupling techniques like the Carter copter croud..

Just to "brag" a bit, I actually had the privelage to witness a jump take off by the small Carter copter demonstrator....boy, what a site, that thing looked like a caged in lion during the ref-up but as soon as the pilot "pushed the switch" the caged in lion transformed into a swan and just glided effortlessly into the air, easily to 150 - 200 ft.....it actually looked good....

THI wrote:for jump take-off you need the ability to prerotate the rotor system to speeds approximately 50% higher that those required for normal flight

Because of the jump, gyro's going upwards, reducing rotor speed at on helluva rate, and the forces working downwards on the blades trying to fly. EEEish.

gyrofan wrote:Johan from Wagtail has gone down that development route with the hydraulics.

Francois at Rhino had his Sycamore converted. Good concept and spins up to about 220 r.p.m. but it is a bit heavy. Sure it saves about 100m on take-off.

Because of the jump, gyro's going upwards, reducing rotor speed at on helluva rate, and the forces working downwards on the blades trying to fly. EEEish.

I'm not sure I follow you? My understanding is that jump-gyros have a variable pitch (collective) mechanism. So the spinning rotors are creating the lift (as per a heli). Other than gravity and drag what "forces" would be working downwards on the rotors?

Was thinking of the drag/inertia of the rotors going upwards. In my mind the gyro is jumping faster than the rotors want to fly - a sudden movement upwards of the rotorhead, and the blades must follow. Guess they found a happy medium between the intensity of jump and the flight of the rotors. Back to the serious pre rotator.

Learjet wrote:My understanding is that jump-gyros have a variable pitch (collective) mechanism.

Interesting, didn't know they 're doing pitch control on gyros.

I am just still thinking - in the event of the compressed undercarriage jump - blades forced faster upwards than they want to fly at that stage, therefore reducing rotorspeed ? Do they still manage a pitch change as well - coarser or finer than normal flight ?

Haven't read much on these - therefore speculating.

Aaha low Level - I see where you are coming from! But I have my doubts about the compressed "spring-loaded: undercarriage theory. Some of the US builds (MonarchButterfly) etc have some long and articulated suspension undercarriages and I think whoever saw this may have confused the extension of the undercarriage after lift-off as incorrectly being a spring-loaded jump take-off. Hence I still think that the lift is coming fron one source only - the rotors.

The jump Gyro's definetly have pitch controll (as Heli collective) on the ROTORS