Another attempt at a low priced helicopter.

[Rotor Rooter]

An initial question.
Is there any reason why this electric motor (http://www.plettenberg-motoren.com/UK/Motoren/aussen/Predator37/Motor.htm) and a planetary reducer cannot be located inside the modified head of a gyrocopter rotor?

If the above will work then it should be possible to add a simple 2-position collective pitch , set by engine torque.

If the above will work then it should be possible to build a side-by-side helicopter, that uses gyrocopter controls and is very economical. A BIG model helicopter, which could be built today.


Anyone want to participate in developing or destroying the idea; on this thread?

Dave

[quadrirotor]

http://www.rotaryforum.com/forum/showthread.php?t=9900

Post #8
http://www.rotaryforum.com/forum/showthread.php?t=3826

Will be more appropriate!...For a two places helo.

But this engine (15 kw) has already been discussed for prerotation, or for a small one place...

[Rotor Rooter]

André

The first thread that you mentioned considers mounting a propeller that rotates with the blades. The postings on this thread appear to show that this idea is not feasible.

The second thread and your post #8 is basically what this new thread is directed toward. I think that the Predator 37 has a very very low reliability for a piloted craft. However, the motor the controller and the batteries are available now. Combining two counter-rotating rotors in the very efficient side-by-side configuration must result in the 'First Manned Electric Helicopter' :first:
Plus it will not be expensive to make.

Contributions and critiques toward this objective may result in an actual craft being built.

Here are some crude initial considerations for discussion (http://www.unicopter.com/0578.html)

Participation requested.

Dave

[quadrirotor]

The first thread that you mentioned considers mounting a propeller that rotates with the blades. The postings on this thread appear to show that this idea is not feasible

Depends on many things...You could use fans, four fans, two at each end of the cross beam, counter-rotating (may be two engines at each end, ass-to-ass)...(see the NASA article on tip-driven helico...)


Sorry Dave, i don't like side-by-side rotors!...Not compact enough!
What is your profil of mission, why electric engines? batteries are a plague!...

I don't like electric engine for sustentation, good only for a tail-rotor + generator on the thermic engine...

[quadrirotor]

May be something like that with electric engines!?...

http://www.rotaryforum.com/forum/attachment.php?attachmentid=27869&d=1162851747

http://www.rc-airplane-world.com/image-files/e-flite-blade-cx-2.jpg

[Rotor Rooter]

André

The future for most vehicles will probably involve electric propulsion. This project is simply a low cost entry point into a 'growth' field.

The side-by-side configuration has the best thrust-to-power ratio of any configuration, and this is important with today's limited battery storage. The side-by-side is not compact in the air, but for transportation it should take up the same space as a gyrocopter. In addition, the rotors do not have to be synchronized.

Dave

[quadrirotor]

The side-by-side configuration has the best thrust-to-power ratio of any configuration

Sorry Dave but, it seems, the choice for a type of rotorcraft as nothing to do with rationnality!!!

[Rotor Rooter]

André,you said;...the choice for a type of rotorcraft as nothing to do with rationnality!!!Are you talking about Igor and his eagerness to get something off the ground? :confused:


The biggest problem today is the weight of electric storage devices.
The biggest problem 70 years ago was the weight of reciprocating engines.

A first viable solution back then was the Focke-Wulf Fw 61 ~ side-by-side (http://avia.russian.ee/helicopters_eng/fw-61.php). Why should not the side-by-side be the best configuration for today's weight problem?

Dave

[Arnie Madsen]

An initial question.
Is there any reason why this electric motor (http://www.plettenberg-motoren.com/UK/Motoren/aussen/Predator37/Motor.htm) and a planetary reducer cannot be located inside the modified head of a gyrocopter rotor?

If the above will work then it should be possible to add a simple 2-position collective pitch , set by engine torque.

If the above will work then it should be possible to build a side-by-side helicopter, that uses gyrocopter controls and is very economical. A BIG model helicopter, which could be built today.


Anyone want to participate in developing or destroying the idea; on this thread?

Dave

Hi Dave. A few questions. When you say install the electric motor in a gyro head are you intending this as a pre-rotator (jump takeoff etc) ? And would it be battery powered or run off a generator?

In the helicopter side by side version are you saying an electric motor in each rotor and are you intending battery powered or would you use an engine/generator for power ? ...and you mentioned 'gyro controls' on the helicopter ... no swashplate? At his point I can't picture your ideas . Please help.

Many thanks
Arnie Madsen
Bell 47 G2

[Rotor Rooter]

Arnie,

The Plettenburg Predator 37 motor is rated at 15 KW (20 hp) and it only costs $1,250.00. It is intended that two of them (one in each rotor) will fully power the craft. The total power requirement for hover from Prouty's calculations is 26 hp, or less.

The intent is to use batteries. Each motor requires 30 - 40 cells / 10-14 LiPo batteries. A ground based GenSet is a possibility for use during longer duration testing within a limited radius of the GenSet.

The motors, batteries and controllers are all currently available, however, modifications to the control will be done as part of the product research and development.


There are to be no swashplates. The intent, with the help of gyro specialists on this forum, is to use a modified gyrocopter rotorhead c/w a pair of teetering blades.

The two modification from the basic gyro rotorhead are;

The pitch hinge will become two separate hinges, on a common axis, except that there will be a space between these hinges where the motor-reducer will be located. The roll hinge will be split in the same manner as the pitch hinge, for the same reason.

Using this picture as an example; http://home.maine.rr.com/rotorcraft/Gyrocopter/gyro%20rotorhead%204.jpg The whole assembly from the rotor bearing down to the lower plates will be opened up to accommodate a 4" diameter motor and planetary reducer, which will both move with the rotorhead.

The thinking is to make the hub-bar of composite material. It will act as a tension-torsion strap and thereby allow the torque between the gearbox and the rotor to set a 2-position blade pitch mechanism.

Obviously the technical assistance of others on this forum would be extremely valuable.

Dave

[Brent_Brown]

That sounds doable.

[quadrirotor]

For info, Dave:

http://www.rotaryforum.com/forum/showthread.php?t=2188

[Rotor Rooter]

André,

Kestrel does not appear to be around anymore.


Anyone,

The web page for the development of the craft proposed on this thread;
Electrotor helicopter with bilateral gimbaled rotorheads. (http://www.unicopter.com/ElectrotorSimplex.html).

Why won't it work? Stick it to me. :boink:

Dave

[quadrirotor]

When you have no collective, you have a problem of reactivity (speed of reaction)...If a reduction unit fails, you could be up side down very quick, before having the time to reduce the speed of the other rotor!...
Why not trying a coax tailsitter?

The god father Bensen tried fixed pitches! he only survived, that's all i can say!!!...There is a kind of correllation between the MR and the TR!!!...

[quadrirotor]

Or may be, you could have two synchronized heads with collectives, and a vectorized tail...like the Touringcopter or the Omniplane beneath...


http://www.rotaryforum.com/forum/attachment.php?attachmentid=16192&d=1130513345

[quadrirotor]

May be IVOPROP could be some kind of inspiration...They have in flight prop adjusting pitch by twisting the blade!!!

http://www.ivoprop.com/inflightmagnumodel.htm

[quadrirotor]

May be there something there:

http://www.braggroup.com/


And you could try the flying carpet of Bensen, the B12...


http://www.aerofiles.com

[Rotor Rooter]

André,

Thanks for all the info.

When you have no collective, you have a problem of reactivity (speed of reaction)...If a reduction unit fails, you could be up side down very quick, before having the time to reduce the speed of the other rotor!...
Yes.
I was also thinking about the problems of a gyrocopter with jump takeoff. The jump takeoff adds to the price, complexity and required piloting skills.

It makes a person think that a simpler helicopter flight-control system should be more attractive than then the above gyrocopter controls. Two of us were just discussing this thread's Electrotor w/ Gimbal and have decided to look at changing it to an Electrotor w/ Swishring. http://www.synchrolite.com/Swishring.html

For this application the ring will not be 'flexible', as shown. It will be a rigid ring and only have the three standard control-rods, which provide the input from the pilot. The swishring eliminates the swashplate and the pitch links from the pitch horns, theoretically making for a simple flight control system.

Additional, the thinking is to use a hub bar that allows twist but no bending.

Hopefully KISS.

Dave

[Ludde]

When you have no collective, you have a problem of reactivity (speed of reaction)...If a reduction unit fails, you could be up side down very quick, before having the time to reduce the speed of the other rotor!...
Why not trying a coax tailsitter?

The god father Bensen tried fixed pitches! he only survived, that's all i can say!!!...There is a kind of correllation between the MR and the TR!!!...

Hi!
I have been searching for information about the B-13 helicopter for a long time but without luck.
Nice to see a picture of it. Do you have any more information or pictures? Anything could be of interest.
Regards Ludde

[quadrirotor]

Production of Dr Bensen:

http://www.aerofiles.com/_ba.html


Bensen
1953: (Dr Igor B) Bensen Aircraft Corp. Raleigh NC.
B-2 19?? = No data found.

B-3 aka Bensen-General Electric B-3 19?? = No data found.

B-4 Sky Scooter 19?? = No data found.

B-5 19?? = No data found.

B-6 19?? = No data found.

B-7M Gyro-Copter 1955 = 1pOAg; 42hp Nelson H-59; rotor: 20'0" v: 75/55/19 range: 125 ceiling: 12,000'; ff: 12/6/55. Powered version of B-7 Gyro-Glider; M for "Motorized."

B-8 Gyro-Copter 1956 = 1pAg. Powered conversion of B-8 Gyro-Glider. Designed for home construction from kits or plans, of which several thousand were reportedly sold.

B-8B Gyro-Boat 1956 = Unpowered flying dinghy for towing by motorboat; rotor: 20'0"; ff: 4/2/56.
B-8H Hovering Gyro-Copter 19?? = No data.

Bensen B-8M Art: side view

B8-M Gyro-Copter 1957 = 1pOAg; 72hp McCulloch 4318; rotor: 20'6" length: 11'4" load: 252# v: 85/65/7 (minimum flying v: 15) range: 80-90 ceiling: 16,500' (>12,500'); ff: 7/8/57. $995 for kit, less engine. Fully roadable; take-off under power in 50'. Fitted with floats as Hydro-Copter and with a hopper as B-8MA Agri-Copter.

B-8V 19?? = B-8M with a 1600cc Volkswagen engine.

B-8 Super Bug 1971 = Advanced version of the standard B-8M with a twin-engine installation to spin up the rotor.

B-9 Little Zipster 19?? = 1pOH; 60-70hp Mercury outboard motor; rotor: (upper) 22'0" (lower) 20'0" v: x/60/0 range: 100. Co-axial rotors. POP: 2 prototypes [N58U, x].
B-10 Prop-Copter c.1960 = Tandem-rotor flying platform. 1pOH; two 72hp McCulloch. POP: 1 [N56U].

B-11 Gyro-Copter c.1964 = All-metal upgrade of B-8H with 72hp McCulloch.

Reported in Aviation Week 5/11/64, Bensen gyrocopters and gyrogliders were to be marketed in kit form by Montgomery Ward; kits to be manufactured by Bensen and sold under Montgomery Ward's 'Riverside' trade name. (— Ron Dupas 4/6/01)

Bensen B-12 (Aviation Week via Ron Dupas)

B-12 Sky-Way 1961 = Manned, somewhat precariously, research vehicle for possible ag operations. Aluminum framework with 10 McCulloch M75 two-cycle engines and 7'0" rotors; ff: 11/2/61. Hovered at 20', flew sideways and backwards with success.

B-13 1963 = 1pOAg; 70hp Mercury outboard motor; ff: 3/4/63. Marketed kit version.

B-16 1974 = B-8M on tri-skis with twin Kiekhafer snowmobile motors.

Mid-Jet 1954 = 1pOH; rotor: 13'0" load: 410#. Tip-mounted ramjets on twin-blade rotor.

X-25 1968 = USAF. 1pAg based on B-8M. POP: 2; [68-10770] as X-25A and [68-10771] as X-25B — the latter was converted to power from a gyro-glider and was first to fly, 1/23/68 (p: Igor Bensen); -25A didn't fly until 6/5/68.


--------------------------------------------------------------------------------

[Rotor Rooter]

André,

Here are 3 sites with low priced helicopters;
http://electrotor.com
http://synchrolite.com
http://unicopter.com


Dreams are exceptionally low priced. :ohwell:

________________________

But seriously;

This principal assembly (http://www.unicopter.com/B329.html#Principal_Assembly) is looking better and better for use in a bilateral low priced helicopter.

http://www.synchrolite.com/1574_Small.jpg

For a much large image of the above drawing click here (http://www.unicopter.com/1574.jpg). Then click the mouse (magnifying glass) on the drawing.

For the Web section on this craft's development see; Electrotor~Simplex (http://www.unicopter.com/ElectrotorSimplex.html)

Dave

[quadrirotor]

What could be the efforts on the commands of this set up with continuous power???
This set up seems to have been used on an helicopter of Cierva-Weir W9...

[quadrirotor]

Other exemples of this set up: Higgins helico and a gyro-prerotator...

[Rotor Rooter]

André,


The rotorhead of the helicopter in your first post is interesting. I wonder if separate collective and gimbal cyclic controls are better than a conventional swashplate or spider control?

The Cierva-Weir W9 has some differences from this craft. It appears that the W9 has;
- No collective.
- Three blades which must have;
- Flap and lead/lag hinges.
- Hydraulically powered flight controls.

- Uses NOTAR and what appears to be a blown yaw aperture.

Do you have more information on the craft in the first of the three pictures?

Dave

[quadrirotor]

That's a french jump tk off gyro on testing yet...

[Rotor Rooter]

Thanks,

It's interesting to contemplate the transitional steps that exist between a basic gyrocopter and a basic helicopter; in respect to cost, complexity and safety, etc.

The partially powered rotor is intriguing idea, for a number of reasons. Unfortunately, as the 'partial' becomes less and less 'partial' the need to overcome yaw becomes more and more of a problem.

Perhaps there is the possibility of a homebuilt with a swiveling tail rotor, similar to what Sikorsky tested many decades ago. During hover the tail rotor counters the main rotor torque. Then it transitions to a pusher prop as the craft's forward velocity increases.

OR

Perhaps the best answer is a pair of smaller identical bisymmetrical main rotors. :D
Don't waist energy offsetting the main rotor torque ~ Eliminate the torque.

[quadrirotor]

There is not a big difference between a jump take off gyro and a helico!...


The question remains: What are the loads on the commands with a rotorhead descibed above??? (gyro rotorhead+collective+drived in the center, not to stress the mast...)

Very important question: this could lead to a simplification of the commands of a cheap helico...

[Rotor Rooter]

André,
There is not a big difference between a jump take off gyro and a helico!... You're probably correct. Plus, there would be even less difference between a gyro with partially powered rotor and a helicopter.
____________

I am assuming that your question relates to the Electrotor-Simplex (http://www.unicopter.com/ElectrotorSimplex.html) and its drawing in post #21 above.
If not, don't read the following collection of comments. ;)


The motor-reducer assembly should weigh about 25 lbs.
This assembly teeters with the hub bar and blades.
The motor and the rotor have the same direction of rotation, therefore both should be subjected to the same gyroscopic precession when the rotor head teeters.
It is speculated that the small amount of additional rotational inertia may add some stability to the rotor.
The collective pitch of the blades is set by the power of the motor.
An electric motor is capable of instantly producing 2 to 3 times its normal power for a short duration, whereas a gas engine cannot. This should be sufficient for clean takeoffs and landings.
Cyclic control is by conventional gyrocopter gimbals.


I suspect that a fully-controllable rotor and its power-train can't get any cheaper than the above.

Batteries are the hurdle, but yesterday a number of auto manufacturers said that they are going to skip the GM and Toyota hybrid approach and go directly to all-electric using lithium-ion batteries.

Dave

[quadrirotor]

You must regulate the pitch of the blades according to the RRPM. The more the RRPM, the more the pitch...Less RRPM, less pitch...

[Rotor Rooter]

André,

IMHO, changes to the rotor thrust will be too slow if the collective pitch is linked to the RRPM.

The intention is to link the collective pitch to the Power (Torque). This way changes to the power of the electric motor will cause instantaneous changes to the thrust. The trick will be to make the twistable hub-bar with the correct amount of elasticity.

Operationally, a takeoff is intended to consist of the following stages;
The motor power, and therefore the blade pitch, are slowly increased, until the rotors are providing 90% of GW.
The motor power is given a quick and large increase.
The pitch and the thrust sharply increase and the craft lifts off.
The Power level is maintained. Therefore the RRPM increases and the Torque (and pitch) decreases.
The pilot reduces the power when the RRPM is sufficient and the craft is clear of the ground.



This is a boring page on the Torque/Pitch Collective Rotor Hub (http://www.unicopter.com/0575.html)

Dave