Minimalist/Ultralightweight Gyroplane from Bike/Trike & Paramotor Engine?

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sanman

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I want to know if it could be possible to build a lightweight minimalist barebones gyroplane using a recumbent bicycle/tricycle, and a small paramotor type engine.

I was trying to decide whether engine should be a 2-stroke or battery-electric motor.
If it was a battery-electric, perhaps there could even be a small pre-rotator in the rotor hub.

I was also trying to decide whether the pilot should be in a reclining posture, like in a recumbent bicycle/tricycle, or whether it could be a prone posture like in a prone bicycle where you're on your belly.
Along with that, I was also trying to decide whether it should be a pusher or a tractor design.
I was thinking that a tractor configuration would allow for the prop to be farther away from the reclining pilot's head, while a prone position would allow the pilot's head to be farther away in a pusher-prop configuration.

The gyrocopter blade could be of suitably smaller size for a barebones vehicle of minimal weight of and of course pilot.
 
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sanman

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So got the idea while looking at some guy using a paramotor while riding a bike:




It made me wonder if a suitably lightweight & strong bike could be the basis for a gyroplane, by supporting an overhead rotor and an engine.




But then I also thought of minimalist recumbent bicycles like this one:



A recumbent bike then has a much tighter center of horizontal inertia, to then line up with the centerline of thrust from a propeller, increasing stability by reducing chance of pushover.
Of course we'd really want a trike instead of a bike, since we need at least 3-point stability when supporting an overhead rotor.
 

sanman

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This is an ultralight gyroplane - I don't know what it's called, whether it's a known model, or if it's some custom design:




But I was thinking that it should be possible to build something significantly lighter than that, which should also fall under FAR Part 103.
 

AeroER

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The vertical tail in the video looks like a Ken Brock gyro.

A face down prone pilot position is dangerous in a crash, and not comfortable or practical for flying. Upright sitting prone might be okay if it's not extreme. Airframe drag is not the problem as top speed is limited anyway.

What is important is getting the airframe plus pilot drag lined up with the vertical CG and the thrust line as nearly as feasible.

I knew a guy in the mid 80's that didn't know much about gyrocopters, and he wasn't about to hear advice, or pleading from his wife. He killed himself on the first attempt at flight of a machine of his own "design" and construction at the end of the runway, diving in from a height just sufficient to be fatal.
 

D Hillberg

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The vertical tail in the video looks like a Ken Brock gyro.

A face down prone pilot position is dangerous in a crash, and not comfortable or practical for flying. Upright sitting prone might be okay if it's not extreme. Airframe drag is not the problem as top speed is limited anyway.

What is important is getting the airframe plus pilot drag lined up with the vertical CG and the thrust line as nearly as feasible.

I knew a guy in the mid 80's that didn't know much about gyrocopters, and he wasn't about to hear advice, or pleading from his wife. He killed himself on the first attempt at flight of a machine of his own "design" and construction at the end of the runway, diving in from a height just sufficient to be fatal.

Not a Brock - Air Command by Dennis Fetters - modified ,,, note the main frame and Tail feathers .
round tube not square tube

Why reinvent the wheel
 

sanman

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Alright, I'd like to show you some more videos, using a real world flying example:










So this is a "nanolight" flexwing trike aircraft that falls under the "sub 70" category in the UK (meaning weight <70kg)
This particular model is Flylight's Adam, and it features a retractable undercarriage, which I really liked.
It typically operates with a 2-stroke engine like the Atom 80 (10 hp) or the Moster 185 (25 hp)
The overall empty weight of this aircraft is 61kg.

I was wondering whether something like this could be adapted into a small Gyroplane concept?

Instead of the fabric wing overhead, there would be the rotor overhead.

Because of the lighter weight of the vehicle, the rotors themselves could be smaller and lighter.
Perhaps they could be composite rotor blades, similar to what these are made from:

What do you think? Does this sound feasible?
 
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Brünner

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So I'm curious for your feedback - why do you feel it's not practical to make a nano-trike into a gyroplane?
If your goal is to make a gyro with a retractable gear, I don't see the point. Gyros make a ton of drag already so having a smaller front profile is in my opinion pointless.
If on the other hand you want to build it as a nano trike for portability reasons, then I might be interested.
 

sanman

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Gyros need thrust equal to half of the gross weight or better to fly successfully.

Moster185 is a 2-stroke engine used for paramotors+pilots where their total gross weight is upto 160kg.

That can be a similar weight target for a gyroplane based on a nano-trike.

If your goal is to make a gyro with a retractable gear, I don't see the point. Gyros make a ton of drag already so having a smaller front profile is in my opinion pointless.
If on the other hand you want to build it as a nano trike for portability reasons, then I might be interested.

Yes, portability would very much be the goal here. Nanolight class were created to allow packing into the trunk or rear of a car or SUV.
A 20-foot rotor could be detached into 2 blades of 10-foot length each.

Lower cost would also be a goal, for more affordability and access.


DSCF0339-768x512.jpg



nano20.jpg
 
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sanman

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But another question I have, is whether a Gyroplane can be controlled via a control bar that's more directly attached to the rotor hub assembly, as opposed to cabling/pulleys/cyclic that add weight & complexity.

Also, what if instead of a rear rudder & tail, you had a rudder on the front, attached to your nosewheel? You would swivel the nosewheel-rudder from side to side using foot-pedals. Same controls would be used for steering while on the ground.
 
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sanman

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Here's an older model (80 kg weight) by the same manufacturer, which I really like - and I keep imagining it as a gyroplane:




There's also an electric version:



Retractable landing gear for trikes has been around for well over a decade now.
 
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Brünner

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But another question I have, is whether a Gyroplane can be controlled via a control bar that's more directly attached to the rotor hub assembly, as opposed to cabling/pulleys/cyclic that add weight & complexity.
I think the old Bensen gyro had a control bar connected directly to the rotor.

Also, what if instead of a rear rudder & tail, you had a rudder on the front, attached to your nosewheel? You would swivel the nosewheel-rudder from side to side using foot-pedals. Same controls would be used for steering while on the ground.

That would be a radical design change, and in order to do it I think you need a deeper understanding of how a gyro flies and the forces at play.
You would lose the propwash on the rudder, which according to my very limited understanding is something you'd want to have.
 

sanman

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I think the old Bensen gyro had a control bar connected directly to the rotor.

Okay, those old original Bensen designs like B-5, B-6, etc are what I was thinking of.
It seems that the style only changed to cyclic control stick because that was what existing pilots of the day were used to.


That would be a radical design change, and in order to do it I think you need a deeper understanding of how a gyro flies and the forces at play.
You would lose the propwash on the rudder, which according to my very limited understanding is something you'd want to have.

If that were the case, then how would tractor designs with the propeller in front and the tail rudder in the back then work?
I thought prop wash can actually even cause problems for aircraft during ground maneuvers, whereby pilots have to adjust their rudder to compensate for that.

If there are aircraft which feature horizontal stabilizers/canards at the front near the nose, then why not vertical stabilizer somewhere up front as well?
 
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sanman

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If you put the rudder on the front you will fly backwards.

Backwards relative to the intuitive motion of the controls?
Maybe that's just something you'd have to get used to.

Or maybe some mechanism could be devised to solve that.
How about turning the nosewheel/noserudder by swiveling your ankles left or right, instead of depressing foot pedals?
 
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