What helicopters use direct tilt teetering hinge like gyrocopters?

yep that would be it..
it is now sold by Phoenix Rotorcraft here is NC and I am a sales rep. for them.

here is the new facebook page where you can see more Photos of this Helicopter.

http://www.facebook.com/pages/Phoen...and-Helicopter-kits-and-parts/159785004074405

It's an interesting machine. I read some of your posts and I'm glad to hear that Phoenix Rotorcraft seems to be encouraging suggestions for improving both the SkyBlazer coax copter and the UFO gyroplane and committed to making them better aircraft. After the Nolan brothers and two other subsequent firms giving it a go, Phoenix Rotorcraft will truly earn their name if they can get any decent number of SkyBlazers (and/or your planned two-seat derivative) up in the sky. I imagine it would be quite exciting for you to be part of that. IMHO, I believe the only real chance you guys would have at accomplishing that would be if you can modify the machine so as to give it the ability to autorotate. I don't think most copter pilots are comfortable flying a machine that doesn't have that capability, even if it's a twin engine aircraft capable of SEO. Is adding the ability to autorotate, something that you folks are working on (or considering), or is that something that is realistically not likely to happen?
 
I believe the only real chance you guys would have at accomplishing that would be if you can modify the machine so as to give it the ability to autorotate.
Is adding the ability to autorotate, something that you folks are working on (or considering), or is that something that is realistically not likely to happen?

Yes that is in the Works,the prototype Phoenix will still have fixed Pitch. but they are plans to make a full collective pitch system as tests progress.

I to did not like the dual throttle control set up of the Sky Blazer and I designed in my head a Regular Collective set up that would be able to increase both throttles when you rise the lever,but by twisting the lever like you would to increase or decrease throttle on a standard helicopter you could then vary the separate engine speeds. I think this would make things a lot less confusing to a pilot that is already helicopter trained.

It is exciting to a point, but I have learned not to get to excited in things,so I am taking a wait and see attitude.

But so far Phoenix is doing what they planned and I am doing what I can to help it grow, but so far I have not made any money.

I do think once Phoenix can demo the machines at some of the Fly-ins ,we will start getting more calls. so far I have replied to 3 E-mails this week requesting info on both the Phoenix Helicopter and and the UFO Gyroplane.

if you have not had a chance to yet, check out the facebook page I made for Phoenix, where I plan to post the newest info and photos as I get them.

as for the 2 seat Phoenix Helicopter, the cabin assembly is at the shop now and the twin tail booms are are the Fiber glass shop. but the fiberglass shop lease ran out and they are now going to be putting up a Building on Anthony's property so the fiberglass shop will be almost in house now.

Things are moving forward,I guess like any new Business venture we will just have to sit back and watch and hope for the best.
in the mean time if you need a Gyroplane or helicopter part made,even if it is just a 1 off part, Give Anthony a call, he is eager to help the homebuilder. give him a call at 919- 340-0038.

here are a few pics of the Nolan/skyblazer with the Rotorheads removed for some updates.
 

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...the prototype Phoenix will still have fixed Pitch. but they are plans to make a full collective pitch system....
But the fixed Pitch, together with the tilted rotor head, is what makes this machine unique.

As a hovercopter (for homebuilders) it looks perfect. Only, what is the price without engines?
Save one engine or put any other 50 hp engine on it. This way, any homebuilder would have some success - without killing himself.

As a helicopter what should the advantages of this unique machine be?
 
But the fixed Pitch, together with the tilted rotor head, is what makes this machine unique.

It's also why they haven't sold more than a handful - how many years has this design been on the market & how many have you seen actually flying?
 
But the fixed Pitch, together with the tilted rotor head, is what makes this machine unique.

As a hovercopter (for homebuilders) it looks perfect. Only, what is the price without engines?
Save one engine or put any other 50 hp engine on it. This way, any homebuilder would have some success - without killing himself.

As a helicopter what should the advantages of this unique machine be?
well we have learned it is Under powered as it is, the new ones will be 100 h.p.

Also will use the Body of what used to be the Falcon gyro and will come with the enigma engine control system,newer heavy duty gear box. and will be at about $115,000 from what I am told.

As for advantage,I was told you can learn to fly it in about an hour. and that was with the old throttle set up. I think with the throttle set up I have designed it will be even easier.

I do think it would be a real good seller with the Collective pitch and larger Rotors.

Again I am taking the wait and see stance,but I look forward to seeing this machine evolve.
 
Back to the Future

Back to the Future

Leviterande's initial post asked the question; "What I am wondering is, is there a helicopter made just like a gyrocopter with a direct tilt teetering hinge? (such a helicopter incorporates also an independent collective of course.)"

Chuck responded on post #2 "None if you mean cyclic control via rotorhead tilt. A component of drive torque will be present in the cyclic control system that will make manual control impossible."
On post #8 Chuck elaborates on the effect of torque due to the Universal joint (also referred to as a Hooke's joint and a Cardan joint)

I agree. If a Universal Joint is located between the axis of the mast and the axis of the rotor disk, there will be a 2-per-rev pulsation when there is an attempt to tip (misalign the two axe). However, this pulsation will be eliminated if a Constant Velocity Joint is inserted between the rotating mast and the rotorhead.


Perhaps "a helicopter has never been made just like a gyrocopter with a direct tilt teetering hinge". However, that does not necessarily mean "that a helicopter" cannot be "made just like a gyrocopter with a direct tilt teetering hinge".


The following should be relatively easy to make. If someone can give a valid or perceived reason why it cannot work ~ please say so;

1/ Locate a Constant Velocity Joint between the rotating mast and the rotorhead. Now, it should not make any significant difference whether the rotor being driven aerodynamically (gyrocopter) or mechanically (helicopter). Of course a tail-rotor will be required.

2/ Then rigidly mount a pair of propeller blades to this rotor hub at 0-deg and 180-deg azimuths, just like Schoeffman's rotor.

3/ Then mount a teetering rotorhead, which has a large opening in the middle ~ i.e two-part teetering hinges, with these blades located at 90-deg and 270-deg azimuths.

4/ Then give the teetering rotor Hub springs or Bi-teetering Offset.

This weight-shift craft should now have faster controllability and auto-rotative ability.


Here is detailed information on a 3-blade Constant Velocity Hub, which can be modified for 2 blades.
Here is information on a widened teetering hub. It also incorporates a torque-pitch collective, if desired.


Or, let other countries innovate. Chinese eye Marine One Contract


Dave
 
The type of universal joint has nothing to do with it.

The Nolan machine worked because it has coaxial, contrarotating rotors which eliminates torque in the gimbal pivots. A tip jet helicopter can also utilize tilt head cyclic because there is also no torque reaction in the gimbal pivots.

With a torque driven main rotor, the component of rotor drive torque that appears in the cyclic control system is equal to: Torque x tan((tilt angle)/2). The form of universal joint is irrelevant. Even with a direct motor drive as part of the rotor system, the whole mess tilting without a universal joint; the problem is the same. Rotor drive torque must be reacted out through gimbal pivots.

Anyone that has flown a gyro with a strong prerotator will have noticed that the stick is slammed over to one side with an abrupt engagement whatever the drive mechanism; hydraulic, shaft, flex cable or anything imaginable except for tip jets. Rotor torque in such cases is resisted by the contact of wheels against the surface and to get to the surface, must pass through the gimbal pivots.
 
The Nolan machine worked because it has coaxial, contrarotating rotors which eliminates torque in the gimbal pivots.
I fail to see how coaxial countrarotating rotors eliminates torque in the gimbal pivots.
It appears that the Nolan helicopter may have a universal joint at the top of its vertical drive shaft, and perhaps a universal joint at the bottom also. The drive shaft may also be telescopic. The Nolan helicopter may also have a pitch hinge that is offset from the center of the axis of rotor rotation.

I am proposing that the 3 axe of the Concentric Double Universal Joint(CVJ) , which is shown on the above linked page, and the 2 axe of the gimbal head all intersect at a single point. There should not be any significant moments generated because there are no moment arms.

In fact , due to the split teetering hinge, it may be advantageous to have its axis concentric with this single point as well.


Dave
 
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Bensen’s coaxial helicopter was also able to use tilt head cyclic control. He maintained torque balance by incorporating a differential gearset in the system. The two rotors did not run at the same speed.

The Nolan Bros. achieved torque balance by means of ground adjustment of differential collective pitch, a trial and error process.
 
The Nolan Bros. achieved torque balance by means of ground adjustment of differential collective pitch, a trial and error process.
Hi chuck,you seem to know alot about this Nolan helicopter,would you mind started a thread and posting the Info you know about these machines, as you know I am involved with the new company and I would like to learn as much as I can about them.

I have heard that 12 kits where sold and some of the older kit owners have already Contacted Anthony about replacement parts, so it will be interesting to see how this evolves.

I did hear that unlike Rotorhawk, the Nolans did provide complete builders manuals and set up info.

after seeing the Video,I wonder what RPM those blades are turning.
 
You might try contacting the Nolans directly, Tim. Both Jack and Herb are quite sociable but they may be sick and tired of the whole mess.

Neither had ever flown anything before setting out to design their won flying machine. Former stock car racers/builders with no aviation background.

I’ve been to their place in Jacksonville but that was a good many years ago. They also put on flight demos at Bensen Days a couple of times but that was also years ago.

The rotors would be running at a pretty good clip; -600 rpm or more, having a diameter of something in the range of 14’ and a chord of ~4”.

My knowledge of the Nolan helicopter is only superficial; just the stuff I’ve observed from having seen it a couple of times.
 
You might try contacting the Nolans directly, Tim. Both Jack and Herb are quite sociable but they may be sick and tired of the whole mess.
yeah I may see if Anthony will give me the number, he has talked to them a few times and said they are nice guys.

would be nice to learn more about the machine.
 
Given that all gyroplanes (most of which are fixed-pitch) can obviously autorotate and land safely without engine power (assuming there is a clear landing spot within gliding distance), why can’t a fixed-pitch helicopter autorotate in a similar manner? Is it because the pitch angle that the rotors in the helicopter would have to be set to in order to generate sufficient lift for VTOL flight would be too high of a pitch setting for flight in autorotation, or is there some other explanation?

If my attempt at an explanation (different pitch angle) is correct, to put things in perspective for me, what is the pitch angle of the rotors for a typical fixed-pitch gyroplane and what is the pitch angle of the rotors on the Nolan helicopter?
 
Flightrisk- My helicycle needs around 8 degrees of pitch to hover in ground effect, more than that to hover out of ground effect, or fly at max airspeed. This takes lots of engine power, and when it goes, there is so much drag that the rotor rpm's decay rapidly unless you drop collective, reducing the angle of attack. When the blades are at flight pitch and the power is removed, the inner driving region of the rotor is much smaller, and is overcome by the much larger driven outer area. The rotorblades pitch needs to be reduced, and this increases the inner driving region so that it can power the outer driven region and sustain autorotation. Stan
 
The last paragraph is the important part:

The collective pitch stick had to be lowered from the level-flight position before landing to provide sufficient stored energy to flare the aircraft. This procedure required approximately 13 seconds and an altitude of 500 feet (152.4 meters).
 
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