Gyroguru

Chek this out!!!!!!!

http://www2.ttcn.ne.jp/~rad/htmeng/e-gyrokit/e-kir.htm

http://www.lily.sannet.ne.jp/nehara/e-goodsaac-2.html

http://www.jrheli.ch/modelle/tragsch...yrocopter.html

Video Link:

http://www.geocities.jp/radjpn/video/e-kir-v1.htm

http://www2.ttcn.ne.jp/~rad/htmeng/e-open.htm

http://www2.ttcn.ne.jp/~rad/htmeng/e-open.htm

tintrax

Thanks Wahid - interesting! I can`t make out if the rotor blades are teetering type or individually hinged. I had wondered about making a teetering type hub for two blades but was advised against it as apparently this is less stable and less successful than the three bladed rotor system I (& most others) have used on my autogyros so far.
Question - Has anybody built a regular front engined wingless autogyro with a 2 blade rotor system with teetering rotors - or individually hinged rotors? What have the results been? Whichever 2 bladed method this Japanese model employs it seems successful. Any comments?

Gyroguru

If you look at the ARF parts closely, you can see the fiberglass piece. It look very similar to the one used by Autogyro Co. of Arizona kit.

Wahid

Lizard

Tintrax,

I have built a regular front engined wingless autogyro with a 2 blade rotor. It flew almost the same than the 3 blade version. However I have not flew much so I can't say it for sure. I tried both methods on the same autogyro. I have pics about the 2 blade version and some new pics about it with the new hub. [link=http://www.kemi.fi/kk019065/models/gyro2/index.html]Those [/link]can be found on my homepage.

There was long http://www.geocities.jp/radjpn/video/hasumi_for_net.mpg video about the ARF-model. It seemed to fly really well. I was impressed with slow flying shown on the video.

ottogiro58

Hi Tintrax !!! Virtually every modern gyroplane uses a two-bladed teeter head, so there is no question of its stability and usefulness. It is very easy to build, and even easier to balance than a 3 or 4 blade head. I started my early gyroplane experiments (teeter head) by using a Bensen-style stick fuselage with a forward mounted KB .40 and 3-channel control. Rotor tilt was used for pitch control. Weight was 4 1/2 lbs. I used rotor blades that were built up, like an airplane wing. They had a plywood spar at the attachment point. The total span was 63", and the blades were very thick at 7/8". Chord was nearly 5". They spun up very easily and had great lift. They also made an incredible "whopping" sound, just like a full-size heli. I used a semi-symmetrical airfoil with a slight reflex. I had no experience in flying gyroplanes at that time, and had difficulty getting the model unstuck from the ground. When I finally held full back stick on takeoff roll, the model leaped into the air at a 45 degree angle !!! I was astounded and could only chop the throttle, watching my model float gently down to earth. The rotor tilt was giving me problems (engine seemed to overpower it), so I played around with different arrangements, cut down blade size, and got further and further away from success. I was not aware of the offset gimbal at that time. I finally went to smaller, lighter models with twin rotors and had great success with those. There is a real potential for this arrangement, however. I still use the two bladed teeter head on my control-line gyro. If you want to try a teeter head, there are only a few things to keep in mind. First, tail clearance is of the utmost importance. The blades should tilt @ 5-10 degrees to each side. Teeter stops must be built in to prevent excessive teetering and tail strikes. Allow for extra room for blade "bounce" upon landing. Secondly, keep the teeter pivot bolt slightly above the plane of the rotor blades for stability. A slight amount of coning angle may be helpful. Thirdly, you may want to try using slightly thicker airfoils and maybe wider blades to compensate for the loss of blade area. Rotor will spin up easier and rpm will not need to be as great with thicker airfoils. Blades do not need to be as heavy duty as heli blades. They are not under nearly the same centrifical force as on a heli. I have flown my twin rotor gyro with a single 2-bladed rotor (please see my photo gallery for a pic) and performance was similar to the twin, but it flew a bit faster. I was using flat pieces of basswood with slightly rounded edges, and much better performance can be gained by using thicker airfoiled blades. I still have the teeter head for it, and would like to try more experiments. Maybe now's the time !!! One more thing, be sure to balance the teeter until it is level, and make sure everything operates very freely. And, as with most gyroplanes, the taildragger stance is preferred in order to allow more air to go up through the rotor on the takeoff roll. Good luck to you and to all who wish to further the gyroplanes' capabilities. Happy flying !!! Charlie Anderson

Gyronut

Hello

2 bladed teeter head system do not work for model autogyro's worth a tinkers toot. Why do you think we are not using them...???

We have poured tons of reaserach into this during the early days of model autogyro's. Now if you use a sub wing then you will get something that fly's but not until then. This is used for roll dampening.

Not wanting to argue with you but if you have something that fly's using a 2 blade teeter head with no sub wing other than a control line model that uses centrifical force to keep it flying then please post a in flight pic of it.

The models shown on the above links use a flapping blade system which illiminates the dreaded dissymetry of lift problem. These work but are not as stable as a 3 blade system.

BTW nearly all of our research was done at the University of Wisconsin's wind tunnel by Dr. Bill Friedlander and Dr. Lester Garber

Respectfully

Rick

ottogiro58

Hi Gyronut !!! The reason no one is using the 2-bladed teeter head (in R/C model form) is because it hasn't been perfected yet. They say that necessity is the mother of all invention, so what better reason to finally develop a two bladed head ?? I guess it will be left for open-minded experimenters like me to cut-and-try until success has been achieved. By the way, Juan De La Cierva did not have a wind tunnel but still managed to produce a successful autogiro. Wind tunnels are not needed. All that is needed is some good ol' fashioned American ingenuity, a basic understanding of what makes a teeter head work, and the guts to go where no man has gone before. I will undertake this challenge, and prove to the many nay-sayers that it is not only possible, but is preferable to the semi-rigid flex plate rotor head. Anyone else out there up to the challenge ?? Remember, No guts, No Glory !!! Charlie Anderson

ottogiro58

Hi Lizard !!! Congratulations !!! I was very happy to see the pix of your successful 2-bladed gyroplane !! I am going to start working on perfecting my 2-bladed teeter head. Your head was interesting because you used individually hinged flapping blades. I think the problems you were having on spinup were caused by the blades drooping below the hub. If you modified the hub so that the blades were always even with the hub (straight across at rest), but could rise above the hub to seek their level, spinup might be easier. Also, thicker and wider blades may help, in order to gain more blade area (solidity factor) and lift. Keep up the good work, and don't give up the development of the two-blader !! Your success is an inspiration to others !!! Happy Flying !!! Charlie Anderson

billf

Hello Charlie...

You are right about Juan de la Cierva and his perfection of the autogyro in the early 20's. In the Townsend book, Cierva's early efforts are pretty well documented. His rigidly mounted rotors (no flap, no teeter, etc.) all resulted in flipping over as the aircraft gained forward speed. Later he went to models and almost by accident one of his models used feathers as the rotor. Much to his surprise (and probably satisfaction) the plane flew just fine. He then reasoned that the feathers were able to flex up and down and that neutralized the uneven lift between the forward-going and rearward-going blades.

Moving to full size gyroplanes, it may be (and I emphasize 'may') that the blades being much longer than our model blades and as a result, more flexible, actually bend up (or flap) to achieve the same effect that Cierva saw with his feathered models---even though the gyroplane rotors are teetering. ( By the way, the "Whistler" (the designer's name escapes me)
published in RCM in 1991 uses a teetering rotor, but it also has stub wings with upturned tips. It flys fast. I built one and had something like 65 takeoffs before I had a successful landing.
I attribute that more to my flying skill than the aircraft design!)

Well, I hope this adds to the continuation of this interesting discussion!

Bill

P.S. Maybe we could arrange an after dinner 'technical discussion' at the Muncie Fly-in.

ottogiro58

Hi Bill !!! It was great talking to you at the Spring Hill meet. I could tell that you are a very dedicated gyroplane enthusiast. As far as the full-size gyros go, it is true that the sheer size and weight of the Bensen teeter head contributes to the stability of the craft. The blades definately rise up and flex into a coning angle, bringing dihedral stability to the system. In addition, the 20 foot rotor can generate tremendous centrifical forces, allowing further stabilization of the rotor. Like you, I have spent countless hours experimenting with rotor systems, and would like to see the perfection of the teeter head (in model form) become a reality. In 1993 I was lucky enough to meet Dr. Igor Bensen (of Bensen Gyrocopter fame) at the Bensen Days fly-in here in Florida. He is a great guy, taking several hours of his time to talk gyroplane aerodynamics with me, and welcomed my demonstration of my R/C twin-rotor gyro. He encouraged me to continue the teeter head experiments, and left a great impression on me. At that time, I had already performed hundreds of hours of teeter experiments, and had a few successful 2-bladed heads performing satisfactorily. Though I spent the next several years flying the twin rotor gyroplane, I never gave up on the teeter head, and after a six year vacation from the hobby I am ready to revive the teeter head project. After 70+ flights on my twin rotor bird, I now have the confidence to fly some experimental craft. I shall keep my fellow enthusiasts posted of my progress here on this forum. It would be great to see you again at the Muncie meet, but I will probably not make it due to tight finances. If I don't see you there, perhaps we shall meet again at the next Spring Hill fly-in. In the meantime, have a great summer !!! Happy Flying !!! Charlie Anderson

tintrax

Maybe if we built our rotor blades flexible enough we could do without hinges (or teetering). But actually blades do flex quite a bit - well I`m sure mine do as I have had a blade strike the fuselage although seemingly having plenty of clearance when still on the ground.
Stabilty - OK, the blade advancing into the airflow lefts to neutralise lift, still seems amazing that this happens automatically to just the required amount. Part of the magic of autogyro flight! But why does the blade lifting kill off lift? This puzzled me until I realised that it is to do with `angle of attack`. This angle is all important as it on this that the degree of lift of a rotor blade (or a wing) depends. When moving upwards the angle of attack on this blade is not the same as the retreating blade, because there is an upward movement, as well as a forward one, the airflow has a degree of downwards flow (because the blade is moving upwards a little). Therefore the angle of attack is less, meaning less lift, balancing out the more lift generated by the faster airflow. Phew!!!!!!
Colin

billf

Hi Colin...

And for precisely the same reason, the retreating blade sees a higher angle of attack as it 'flaps' down, thereby creating sufficiently greater lift to balance the forward-going blades.

What really gets interesting, however, is that as the forward speed of the aircraft increases, the airflow over the retreating blade begins to flow from trailing edge to leading edge near the hub. The faster the flight, the more the 'rearward' flow moves out from the hub. Or, should
the rotor slow down the rearward blade can completely stall!! (Bad Deal!!)

Bill

billf

Yes, Charlie Spring Hill is wonderful! It is particularly nice for us 'northerners' to get a breath of spring a bit earlier than we would here in Wisconsin!

By the way, you may recal my frustration with the little Cox 02 trying to get it to run long enough to get my attempt at a miniature gyro into the air. At the suggestion of Dave Platt, I have now acquired a PAW 03 diesel, which runs just great and idles beautifully. So perhaps, now I'll be able to make some progress on that project. (With tongue in cheek I say that I'm not ready to try a teetering two-blade rotor on it, yet...so I'm sticking to the flapping three blade. <G>)

Bill

ottogiro58

Hi Bill !!! Wow, the little diesel sounds like a winner !! Let me know how that works out. The teeter head will be a challenge, but I have much experience with them. I hope to have one flying within a month. In the meantime, I will continue having fun with my twin-rotor bird, and hope for the best. Maybe others will undertake this challenge, and share their success stories with us. Two (or more !) heads are better than one, and with more people trying to solve this problem, success should come that much quicker. I believe the key is to use thicker and wider blades, and to use slightly weighted blades and/or a rubber damper of a sort. I remember the old Cricket helicopter, with its teeter head. It used a small thin piece of music wire as a damper for the teeter system. Time to cut-and-try !!! Happy Flying !!! Charlie Anderson

chrisd540

Hey I would like to know how to buy on of those autogyros from japan please give me as much info as possible. And if i can buy one from in the states THANKS

BiplaneCrasher

Who carries this autogyro in the usa? It's pretty cool for an arf...

ottogiro58

Hi 4tecman !! I still have no clue about who is actually selling this kit in this country. If I find out, I will email you and let you know. It does look great, and probably flies as good as it looks !!! If you find out who is selling it, please post the dealer information on this forum. Thanx !!! Charlie Anderson

BiplaneCrasher

Sure thing, I would love to help.

Warren

My Feedback: (72)

Any ideas on how/where to buy one of these yet?

iwadmin

The company in Japan that has created this kirara design is called [link=http://www2.ttcn.ne.jp/~rad/]RAD[/link] (RC Aero Design labs). A company called AKmod in Magden Switzerland distributes the Kirara for the Japanese company.

[link=http://www.akmod.ch/index.html]AKMOD[/link] GmbH

Gaispelweg 17

4312 Magden

Telefon: 061 843 00 00

Telefax: 061 843 00 10

E-Mail: [email protected]

I have sent e-mails to all known addresses for a responce about getting one of these in the U.S.

The website now has videos of the Kirara flying.
[link=http://www2.ttcn.ne.jp/~rad/htmeng/e-open.htm]http://www2.ttcn.ne.jp/~rad/htmeng/e-open.htm[/link]

iwadmin

fyi

the following is an e-mail I received in reguards to the Kirara autogyro.

Hello John

For the moment there is no distributor in the US.
You may contact Helikopter-Baumann. They are specialized in US mail orders.
www.modellhubschrauber.ch / [email protected]
You will save shipment costs if you purchase sevral at the same time.
If you have any further questions concerning Kirara, don´t hesitate to
contact us.

Best Regards

Andy

A. Kessler

++++++++++++++++++++
AKmod GmbH
Gaispelweg 17
4312 Magden
Switzerland
Ph. +41 61 843 00 00
Fax +41 61 843 00 10
[email protected]
www.akmod.ch
++++++++++++++++++++

John Warren to schrieb:
> Hello,
>
> I am interested in your autogyro plane Kirara. Is there a distributor in
> the USA?
>
> I have people here who would like to purchase.
>
> Thank you!
>

gyronuts

Hi,
Just been checking the european websites. It would appear that this autogyro costs approx $485. Wow!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
I have e-mailed couple of them for further info on shipping etc and will let you all know. But it looks to me as if Arizona autogyro company are everyones best bet for gyros. I attach some photos of my latest electric gyros both awaiting the weather to test fly. Bill Macleod

gyronuts

Hi,
Tracked down a company in Europe and eventually a supplier in the UK.
He has a demonstration model but due to the cost of the kit £300 ( approx $540 YES $540!!!!!!!!!!) has sold a few but he has decided not to stock the model due to its cost.
However, he said "If you want one, you can buy my demo model, without motor and radio for £200.00. Along with a spare pair of new blades."
His name is Martin Briggs of Rotorsport and can be contacted on [email protected]
or [email protected]. Phone number +44 (0) 1531 635298.
Bill

bruce_c

I see that RAD (the manufacturer) is stating an RRP of 28500 yen in Japan which is about £145.

Question is, is there an easy way to order this from somewhere in Japan?

hercdriver7777

Hey guys,

I am a US mil type in Japan. Mostly into Helis but saw a bunch of threads on this thing here and on other forums so I have been on the look out for it. I just ordered one from my LHS and should have it by this Sat. I could probably order a bunch of them and be able to ship them to the states for around $350 if anyone is interested