Rotortec Clouddancer - Innovative Single Seater

[troed@aon.at]

Hi Gyro-Fans!

Here comes another brand new machine from good ol´Europe:

http://www.rotortec.com/cms/index.php?section=home

.... and it´s already flying and will be tested by Andreas Siebenhofer down in Hungary.

What makes it special:

The Prerotator is a 60V- linear - electric - motor energized by li-ion batteries good for 20 run-ups (unfortunatley it is already patented). The articel ´bout the prerot (find it in "News") is in German. Net weight diff. to conventional prerot is stated as 0 and it´s fully automatic (1-button-start-up)

Motor Specs are still with the Hirth engine (2-stroke) but test-gyro will come with a Wankel-engine (FINALLY !!!)

Will report ´bout how it flies as soon as I get a chance to.

Angelo

[ROTORTEC]

This is a Pic. of the Gyro.

47000

[Timchick]

Nice paint job.

[troed@aon.at]

Hi Rotortec !

What keeps You at home in Germany ? We are waiting for You at LHFM ! Franz already told us so many things ´bout Your machine we can´t wait to see it flyin´ any more.....:wave:

Angelo

[Russ Hobbs]

Any chance they'll make a kit for the US market. Looks like they put a lot of attention to detail, Very nice.

[ROTORTEC]

Hi Angelo,


47027

Sorry first for letting you down on promises made. We have tried to visit
You at LHFM time came short and we had to made changes in our agenda.

The ILA Berlin Air show has been planed for a bit longer and to cancel this
one was not possible and not our intension.

We running short on time “Tannkosh” the largest UL Event in Europe is coming Up, and we have to be prepared. We will visit you as soon as we can and time Permits, please be waiting you will not be disappointed. We have new things coming but please give us the time to test, evaluate and deliver what we have in mind, for better
Gyro Products at the future.

John
Rotortec

[dimwit]

I love that pod. I wonder if it could be retrofitted to a dominator?
All in all, very nice gyro. I would like to know some more info on the prerotator.

[Hognose]

Some comments:

It's unlikely with the value of the US peso being so low, that Rotortec could sell machines profitably in the USA. Same-same Canada to the extent that our dollar has drug theirs down. If anything, now is time for US manufacturers to take on the European market,

Making a similar pod for a Dominator would scarcely be a technical challenge. There's no magic to working fibreglass. You would need to be cognizant of the weight, drag, and lateral area effects of an enclosed pod. All of these have safety implications.

If you've flown a Diamond aircraft or anything with a bubble pod like a glider, you already know that being under glass with no sun visors can be unpleasant.

A rough translation of the article's section on the Rotortec prerotator:

The Rotortec firm, a newcomer to the gyro scene, which offered an exciting looking item in its "Cloud Dancer" at the last AERO, offers, just one year later and immediately before the final type approval of its machine, something that will be world-changing in the field: the hybrid prerotator.

The connection to the motor and the previously required mechanism are no longer required. Prerotation is taken over by a 60 volt electric motor, which sits in the center of the rotor and applies its thrust right in the center without putting any loads on any control element. An individual programmable control unit undertakes the smooth acceleration of the rotors to about 240 rpm within a minute of the push of a single button, and declutches itself automatically when preset parameters are reached.

During the takeoff phase, the pilot doesn't have to concern himself with the mandatory management of the prerotator.

After landing, the control unit can brake the rotors to a stop and lock them in the pre-set parking position.

As power source the most modern lithium batteries are used, which also power all the other onboard electronics. They are in position to carry out some 20 takeoffs without recharging. The entire weight of the hybrid system is 11 kilograms (in American: about 24.2 lbs). But because this can replace the 5 kg (11 lb) lead battery, it entails an overall net weight reduction.

That's a rough, not certified, translation and probably has some errors in it and some places where I could have made the grammar more English and less German -- but hey, it's free. The source page in German is here:
http://www.rotortec.com/cms/index.php?page=838

I don't quite understand why they call it a hybrid system, as it does not appear to recharge itself inflight. Perhaps I misunderstand.

cheers

-=K=-

[bpearson]

Making a similar pod for a Dominator would scarcely be a technical challenge.

It isn't. Just buy one of Jim Montgomeries pods and copy it!

[dimwit]

I'm not planning on this. I was just wondering.
My pod from Ernie should be here monday or tuesday, I hope.

[helipaddy]

Heres the Merlin Gyro

http://www.gyrocopters.co.uk/html/merlin_gts_autogyro.html

[troed@aon.at]

Hi John !

No problem ! I was speaking with Franz (Frank), the elder heli-constructor, and he revealed to me some specs (prerot and Wankel-engine) so I was eager to see these innovations. But of course biz comes first......

Anyway, since I will be around Innsbruck and Munich in the next 6 weeks I will pass by Your place to get a look.

I´ll call You one or two weeks in advance.

What might interest the community most is Your patented prerot. Can You give us some hint how it works ?

Angelo

[greeny]

I don't quite understand why they call it a hybrid system, as it does not appear to recharge itself inflight ...
I'd call it a 'hybrid system' if the electric motor was used as a partial drive for the rotor. This would of course require a generator that supplied up to 5 kW of power (close to 100 A at 60 V). And a motor and a control unit to handle that power.
Not that it was likely for such a setup to pass German certification - but it certainly would be a progressive approach.
Just for a simple prerotator, I fail to see what advantage an electric unit should provide.

[ROTORTEC]

We have called it Hybrid for this reason !!

-Spin up the Rotor from Batterie Power for start up.
-Recharge the Batterie during flightfrom the spinning Rotorsystem.
(1 Start up will need 10 min of flight to recharge the Batterie again.)
-Use the system as Brake for the Rotor on the Ground.
(Brake- Effect will recharge the Batterie to)

John
Rotortec Germany

[Schlagschrauber]

Hi, John!

Great that you & your Company started to give us some more information in this forum. Being interested in your Gyro's innovations since the Aero 2007 I missed the opportunity to ask my questions.

I have some concerns about the "Hybrid" prerotator. If I understood available descriptions and rumors correctly there will be LiPo batteries with the capacity for up to 20 prerotations to 240 RPM. In order to reduce weight there will be no other conventional battery or generator.

Using the prerotator motor as a generator: isn't this much less efficient than a generator directly connected to the motor? (Engine => Prop => Rotor => Generator vs. Engine / Generator).

Isn't it a big disadvantage to produce additional drag / resistance on your rotor system? How much can the drag increase on case of an electronic malfunction?

I remember that LiPo batteries are quite sensitive, e.g. explosive when short circuited. How is this risk avoided? Where will the batteries be located (The deeper the better and hopefully in some distance from the fuel tank)?

What about operations during wintertime? LiPo will be damaged when operated below 0° C or above 60 °C?

However - I heard of some of your test flights. So you probably solved all these problems. I'm really curious and hope to see you soon ...

Holger

[ckurz7000]

Nice to see you here, Holger! Come on in, the water's warm :-)

-- Chris.

[troed@aon.at]

Actually I see a lot of advantages in such a system:

as I understand the construction the gear-wheel of the prerotator on the rotor-head is replaced by a "magnet-wheel" and encased in a fixed housing containing the copper-wires.

So the "magnet-wheel" acts like an electric motor comparable to an electric-axis-motor on electric cars driving the wheel.

Thus You need no clutch and transmissions from the motor to spin up the rotor. The mechanical systems suffer from fragility and wear which this electric system does not.

If constructed wisely the weight of this electric prerotator-motor on the rotorhead is compensated by now unnecessary transmission-tubes and clutch and the Li-batteries are lighter than Pb-accus.

Of course the calculations have to be seen or tested in real life but I don´t think that the "drag" of the motor can reduce rotor-rpm more than 5-10 rpms if at all since this motor rotates passively in flight.

Of course it would be fine to enhance the system to prerot rpm of 280-300 but development has only started. Development of Li-batteries brings innovations every month (new nano-tech-systems) and they are very well tested in electric cars. I´m pretty sure John uses established safe batteries from electric cars industry.

All in all it is very intelligent system reducing clutches, gears, and tubing behind the rotor-mast and could be a real breakthrough.

What hits me most in all threads is that whenever a new idea arises and a (already working) system is presented the first reaction is always rejective.

We as pilots of gyroplanes that start to become professional flying vehicles should be maximum open to innovations and - when proven to work nicely - adopt them positively otherwise development of our flying vehicles comes to a stand still.

Just remember that there is a new Wankel-Rotary-Engine with 120 hp that is undergoing ASTM-cert. in the USA ....... as an aletrnative to Rotax.

Angelo

[Schlagschrauber]

Yes, Angelo!

I'm very conservative and sceptic with most innovations.

And I could give you lots of examples: big ones: such as the Cargolifter concept, and also small ones: such as the Porsche Flugmotor, ...
Great ideas, but physicall impossible (Cargolifter) or not competitive enough in the end.

You remember the definition of a pessimist?

A pessimist is a well informed optimist!

Of course there are great inventions and a permanent evolution also in the gyrocopter business. But it is risky to head always for the cutting edge.
I already used an electric car 15 years ago, for example. But: always freezing in the winter and having an endurance of less that 1 hour or 40 km is boring in the end and you return to a classical combustion engine.

So my intention is not to badmouth each and every new idea but to also consider possible disadvantages. If my personal safety depends from it I prefer a good old million and million times proven Pb battery instead of a super modern LiPo such as in my mobile which has to be replaced once every 2 years at least. In my mobile I prefer a LiPo, as long as my life doesn't depend on it ;-)

I just want to avoid the disappointment as a consequence of missed expectations.

Bye, Holger

[Hognose]

We have called it Hybrid for this reason !!



Ah, OK. So the system will recharge from Rotor RPM in flight, and also recharge from regenerative rotor braking. That is a true hybrid system, but that wasn't clear to me from the magazine article.

Thanks for the explanation, and good luck with this clever new device.

cheers

-=K=-

[Greg Mitchell]

G'Day John,

Good to see you are posting here.

I have been emailing John off and on for over a year now. So I have been patiently waiting to see a video of this wonderfull new innovation. Angelo makes a good point on how many threads turn into a Shyte Fight over new product.

One thing I can add....the new pod is 'oversized' to cater for larger human beings around the world.
USA closely followed by Australians in the 'oversized' department.

Mitch.

Mitch

[bones]

G'Day John,

One thing I can add....the new pod is 'oversized' to cater for larger human beings around the world.
USA closely followed by Australians in the 'oversized' department.

Mitch.

Mitch

Some of us might be but not all are over sized :yo::rolleyes:

[Greg Mitchell]

225lbs! What's yours Bones? Have to be close, surely! LOL.

[troed@aon.at]

Been visiting John yesterday when doing a biz-trip around his place.....

I just can tell You, this guy is a genious and gyro-lover out of passion. He develops his gyros out of fun... and sells them just by the way w/o big marketing.

As heli-pilot with hundreds of hours his main profession and company works on environmental stuff for hospitals and the gyro-manuf started as a hobby.

Except very few things (e.g. windshield, motor, prop, DragonWing-blades) he manufs every single part (also composite prods) in his company workshops having now 6 people working on gyro-projects.

He showed me all the folders of construction-drawings of every single part THAT did NOT go into production since they did not pass the "real-life" stress tests.

Concerning the history of the Clouddancer he told me the story: he wanted to build a gyroplane for himself and liked the design of the British MERLIN most to have a start with his own gyro and - yes, he admits it freely - took the basic geometry and cabin design of the Merlin and started to improve it.

As said before, every single part is CAD-constructed, calculated by an external material- and aerodynamic physics guy, then machined in his company, investigated for structural integrity with X-ray and ultrasound (yes, I saw it with my own eyes, coulnd´t else believe it) and then brought to "real-life" testing.

He reminded me somehow of the Teutuls from OCC but in his case he likes "destroy-tests" for passive safety design in case a pilot smashes the gyro. Only after having passed all these testing the part comes into serial production with very narrow margins in precision. For this issue he is a real maniac.

His patented invention of the electric prerot is already known and I can tell You: it works marvellous and w/o flaw and it is astonishingly LIGHT and it really works automatic (one button automatic start-up).

The Wankel engines he will build into the clouddancer already passed ground tests and come into flight testing next week. He put TWO 15 kg (incl. carb) Wankels above each other with a belt driven prop in the middle. In case one quits You can fly with the second one. They produce around 70 hp together, run wonderfully smooth and come from a military project. They will come into serial prod by August this year.

And, Boy, then he showed me what else´s he has in pipeline and I had to swear a holy oath not to tell but if his ideas work in real life it will be a little (and affordable) revolution in rotor-head- and rotor technology.

What makes me optimistic that this jewel of a gyroplane will be available in the US is that the entire Clouddancer-frame is held together by screws thus making it easy to homebuild it for more than 51% and it is still affordable at a prize of 35.000.- €.

In two weeks Andi Siebenhofer will have two Clouddancer for hard-testing down in Hungary and I reserverd a test flight for me, too. I´ll report then.

Just keep a close look at this guy and his gyros...............

Angelo

[Greg Mitchell]

SIDE BAR:

Aussies outstrip the USA as No1 Fat Cat Nation

Apparently you dont need to upsize everything to upsize......

Good thing John made that pod bigger.

Still waiting to see video of the prerotator

Mitch.

[troed@aon.at]

First static thrust tests revealed 30% increase in thrust with the Dual-Wankel-Installation compared with the two-stroke-Hirth-engine.

Ground tests finished.

Flight test start next week.

Angelo

[ROTORTEC]

Tannkosh 2008!!

Thank you for all the comments made during the BIG Event, Germany 2008
2 Pic,s of the Gryo,s shown there.

[Dale Young]

That's one COOL lookin' gyro!!!:first:

[akoschier]

More static thrust compared to Hirth does not surprise- more power/more thrust - but are there any news on the "dual wankel propulsor" and how can I get in touch with whoever has done that.
Name, address,phone # plse.
Thanks,
avk

[autogyro]

Dear John
how about the performance of your hybrid prerotor system?
how long does the prerotor system spin the rotor to default speed RPM? and what is the RPM?
how many times will the battery recharge?
Regards
Edward.

We have called it Hybrid for this reason !!

-Spin up the Rotor from Batterie Power for start up.
-Recharge the Batterie during flightfrom the spinning Rotorsystem.
(1 Start up will need 10 min of flight to recharge the Batterie again.)
-Use the system as Brake for the Rotor on the Ground.
(Brake- Effect will recharge the Batterie to)

John
Rotortec Germany