Synchropter helicopter.

[quadrirotor]

OK, no less than that!
Now, how can we make this affordable!?

[quadrirotor]

OK, Dick Degraw is the KING!!!

[Rotor Rooter]

quadrirotor,

Here's a picture for you.


This is all that is left of the worlds most advanced helicopter of its time.

[quadrirotor]

Thanks Dave, what a pity!...
This one is not bad either!...

[Rotor Rooter]

quadrirotor,

A gentleman has done a tremendous amount of work, number of years ago, toward the building of a full size replica of the Flettner Fl-282. It was to be flown once and then place in a museum. He went to England twice to reverse-engineer the only Fl-282 frame in existence [picture in my previous posting]. He had even arranged the loan of the actual engine used in the helicopter. In addition, he supplied information to Steve Coates, which was incorporated into his book 'Helicopters of the Third Reich'.

Unfortunately, we have not e-mailed in a long time.


You have mentioned on the forum and in a private message the possibility of a low cost synchropter being built. IMHO, it may be a long time, if ever, before this sort of a craft comes about. This gives the reasons.

Coincidentally, I just had a long conversation with one of your former countrymen in France. He, me, and a couple of others have expressed an interest in developing and building a version of the UniCopter.

Should there be others who might be interested in participating, in any way, in the development, or manufacturing, or testing, etc. of the various components required for a very advanced rotorcraft, a posting or private message will be welcomed.


The dream never dies.

Dave

[quadrirotor]

Originally Posted by Rotor Rooter

quadrirotor,

.................

You have mentioned on the forum and in a private message the possibility of a low cost synchropter being built. IMHO, it may be a long time, if ever, before this sort of a craft comes about. This gives the reasons.

.................

Dave

Hi Dave;
the reasons you gave concern the Synchrolite and the unicopter, which is not an homebuilt oriented design...

The main advantage of my concept (THE TOURINGCOPTER) is that there is no swash-plate, only push rod (inside the masts) for collectives (roll authority), so this eliminates a lots of problems (birds strikes fear, vibrations in transitionning, fatigue, etc...) and with the fan blowing on a rudder and elevator, you have a full authority on yaw and pitch. The kaman or flettner synchro are a bit lousy on yaw...

One other advantage of the concept is the use of automobile parts for the transmission, a bit like the philosophy of:

http://www.pawneeaviation.com/

My proposition is a concept which is really homebuilt oriented; and an open concept.

The concept of the Hummingbird of Dick degraw is, essentially, the one of the Flettner 282...


The Unicopter: scaring and too small!...

[Rotor Rooter]

quadrirotor,

is that there is no swash-plate, only push rod (inside the masts) for collectives (roll authority),

This sounds very similar to the Mini 500. If so, its operation is basically like a swashplate, I think.


This is a list of every intermeshing helicopter, which I have ever come across.


Different strokes for different folks.

My 'humble' objective is simply to overcoming Charles Kaman's concern, when he said;

"You only have one pure helicopter development program in the country, the Boeing-Sikorsky Comanche, and you have one convertiplane, now called a tiltrotor, that's the Bell-Boeing Osprey. That's all there is and there are no others in sight. None on the horizon, so what's being bought was developed a long time ago, 20 years or more, or variations are being bought.
So the verdict is clear, there isn't any other thing that's going to happen on the helicopter front."


Time for Generation II Rotorcraft

Dave

[quadrirotor]

Dave,
You are right for the mini500, this is a kind of swash plate...but the rotors of theTouringcopter have NO CYCLIC only one push rod (for collective) by mast which is actuated, like the tail rotor of a "monorotor", through a double concentric row balls bearing, beneath the gearboxe...very rustic hardware!

The touringcopter is HOMEBUILT ORIENTED (no electrinic gizmo for piloting assistance in flight!) for touring private flight...but Charles Kaman is right for the military market...there is a convergence towards the monorotor with a (may be an electric) fan tailrotor and The QUADRIROTOR (no swash-plate, i think...)

The QUADRIROTOR... and its private imitation! the Xantus...

[quadrirotor]

Dave, can you imagine a small (Chinook or Banana) quadrirotor that is a tandem of two systems of simplified synchropter, linked by a non-working drive-shaft (working only if an engine fails)...four small engines, no swash-plate, no tail-rotor, autorotation enable!...a flying Winabago!... The RVcopter!...

[Rotor Rooter]

can you imagine a small (Chinook or Banana) quadrirotor

No.

[quadrirotor]

[Rotor Rooter]

quadrirotor.

Here is a thesis on a small (homebuilt) quad-rotor, which might be of interest.

Dave

[quadrirotor]

Thanks Dave;

if life is boring you, take this one!

[Ga6riel]

Originally Posted by Rotor Rooter

quadrirotor.

Here is a thesis on a small (homebuilt) quad-rotor, which might be of interest.

Dave

interesting thesis'
i dont think they managed a successful degree of ease of control, but there is clearly scope to do better (this is the standpoint from which these machines ought be judged, payload as an aside)
and while satisfactory for a UAV
what about autorotation ?

[quadrirotor]

Dave, i was told that three guys are building a synchrop...It looks like the one on the photo with two big rudders at 45° for better yaw control (they want to use it as a test-bed towards a composite airplane-shaped airframe). It has teetering rotors which look like EXEC ones with limited teetering by a kind of centered multilayered bushing with progressive hardness, no delta3, and a T-shaped plate on a big spring with two bearings as swash-plates, for full control of the pitch of the blades (as FLETTNER did), control through push-pull rigid cables, a Subaru EJ25 engine with the original disk-clutch, bell housing, with multi-third-car-members as gear boxes including a sprag oneway clutch...(seems heavy but rugged...)
Did they contact you?