2 stroke thread (with occasional F1 relevance!)

[joshuagore]

Hello Rodak

This photo shows a windsurfer:

https://www.pattakon.com/Fly_files/Wind_Surf.jpg

From Wikipedia:

“In 1948, 20-year-old Newman Darby was the first to conceive the idea of using a handheld sail and rig mounted on a universal joint so that he could control his small catamaran—the first rudderless sailboard ever built that allowed a person to steer by shifting his or her weight in order to tilt the sail fore and aft.”

Doesn’t it remind the way the pilot of the Broom_Flyer controls his flight?

Thanks
Manolis Pattakos

What acts as the centerboard or Fin(p.s. yes people shred without a center board, very skilled people)? You will notice a trend in sailboarding, most companies are going to hydrofoils to make the barrier to entry easier for beginners. I am sure this has something to do with the mechanics you are speaking of. Also the water below is a pretty corrective force compared to the wind above, do you expect a similar counter acting force with the propellor on top and bottom?

[OO7]

Hello 007

A crucial problem of the design is the overloading of the “line” (if it is “line” and not “point”) contact between the track roller bearings and the “waving surfaces”.

The Bourke engine:

https://www.pattakon.com/pre/Bourke.gif

had the same issue .

The Revetec engine (with its true “line” contact between its track rollers and its cam lobes) didn’t worked reliably.

Theoretically the rollers keep contact with the waving surfaces all the time; but in practice they strike and rebound digging the ramps.


A far better design in this class (track-roller-bearings rolling on cam-lobes to replace the conventional “crankshaft – connecting rod – piston mechanism) is the following one:

https://www.pattakon.com/greco/Greco_Single_Cam_Dis.gif

https://www.pattakon.com/greco/Greco_Single_Cam.gif

Thanks
Manolis Pattakos

Thanks Manolis, I'll look into it.

[nzjrs]

“In 1948, 20-year-old Newman Darby was the first to conceive the idea of using a handheld sail and rig mounted on a universal joint so that he could control his small catamaran—the first rudderless sailboard ever built that allowed a person to steer by shifting his or her weight in order to tilt the sail fore and aft.”

Doesn’t it remind the way the pilot of the Broom_Flyer controls his flight?

This thread has been a great way to learn about uncommon engine designs, including yours, which interests me greatly!

But when I read something like the above then all I can do is thing back to my studies where we learned that intuition is no match for calculation. We were given the example of Franz Reichelt to remember this point. Please I encourage you to be careful and not test these intuitions in flight.

[manolis]

Hello Acula

You write:
“Now look at the size and especially the surface area of the sail compared to the size and surface area of a human. Even if we aren't "aerodynamical transparent", we generally aren't very efficient in redirecting an airstream with our body. That's also why we're utter crap at gliding without a wingsuit or a wing on the back.”


Quote from the 5th post in page 187:

• “And standing slightly apart from them all is ex-Swiss military pilot Yves Rossi, whose extraordinary Jetwing literally lets him dance with aeroplanes in the sky. It needs to be launched out of a plane, though, so while it certainly looks like an incredible experience to fly, it can't lift straight off the ground like the others.”

End of Quote


With only an altimeter and timer, Rossy uses his skin and ears as airspeed indicators.

"You feel very well, you feel the pressure," Rossy says, "you just have to wake up these senses. Inside an airplane we delegate that to instruments. So we are not awake with our body."



As Rossy says : "I am the fuselage, and the steering controls are my hands, head and legs"

Thanks
Manolis Pattakos

[Pinger]

Manolis - have you identified your market for this?
I heard Hyundai are working on an electric four seater flyer.
Four key points to consider.

Hyundai's clout. If/when they want to accelerate the programme, they have the resources to do it.

Electric. I can't see acceptance for anything but zero tailpipe emissions for city use. Yours would be better suited to out of city/ third world where its superior (fuel) range would be welcome and better suited to the existing (re-fuelling) infrastructure. Invariably in those environments load capacity will be requested.

Four seater. Who buys/drives a one seat car? Even two seat smarts never really sold.

Four seater. Anything above one seat means a pilot can be employed. Learning to fly solo flyer is going to be arduous, time consuming and thus expensive. A pilot alleviates that.

I can much more easily envisage a Hyundai four seat electric flyer with a trained/experienced, insured pilot and three passengers with their backpacks onboard in a city than I can an ICE powered solo flyer. Equally I can flip that for a farmer with a large area to cover (but he'll probably want to be able to carry tools - a drone can be used if it's only observation is required), or other rural applications so long as there's fuel. Is your flyer expected to be suited to both those environments?

[Dr. Acula]

As Rossy says : "I am the fuselage, and the steering controls are my hands, head and legs"

You riped this statement of him out of any technical context. It's not that simple.
First of all, if you look at pictures or videos of Yves Rossy with one of his Wings on, theres's something quite noticable. He doesn't wear the wing at the part of the body where anyone would think it would be most comfortable, the upper back, like a simple backpack.
Instead he wears it at about the hight of his waist. And there's a very good reason for that. This setup puts the CoG of his body and the CoL of the wing very close togheter and makes it nearly effortless to control. This way he has to just shift his CoG a little bit and it will have a clear effect. Also, he can actually move the wing forward and back a little in flight to adjust the CoL. He uses not so much the aerodynamics of his body than his ability to actually move his limps, head and body around to move the CoG.
For instance if he bend his knees, so his lower legs are 90°angled to the rest of his body, he will create a pitch down moment, because the Cog of his body has moved to the front a bit.

[J.A.W.]

Manolis - have you identified your market for this?
I heard Hyundai are working on an electric four seater flyer.
Four key points to consider.

Hyundai's clout. If/when they want to accelerate the programme, they have the resources to do it.

Electric. I can't see acceptance for anything but zero tailpipe emissions for city use. Yours would be better suited to out of city/ third world where its superior (fuel) range would be welcome and better suited to the existing (re-fuelling) infrastructure. Invariably in those environments load capacity will be requested.

Four seater. Who buys/drives a one seat car? Even two seat smarts never really sold.

Four seater. Anything above one seat means a pilot can be employed. Learning to fly solo flyer is going to be arduous, time consuming and thus expensive. A pilot alleviates that.

I can much more easily envisage a Hyundai four seat electric flyer with a trained/experienced, insured pilot and three passengers with their backpacks onboard in a city than I can an ICE powered solo flyer. Equally I can flip that for a farmer with a large area to cover (but he'll probably want to be able to carry tools - a drone can be used if it's only observation is required), or other rural applications so long as there's fuel. Is your flyer expected to be suited to both those environments?

Here is an electric 'sitdown' individual 'flyer', seems they have a fair few limitations:

https://flyer.aero/


&, back on topic, check this link for Kevin Cameron's take on F1 2T potential:

https://www.cycleworld.com/story/bikes/ ... -1-future/

[manolis]

Hello Joshua Gore

Impressed by your work with Russ Emanis, as presented at https://joshgoreworks.com/portfolio/ody ... -aircraft/


You write:
“but I can't help but wonder, now that you have this compact power unit, why not use the easiest method available to prove flight, then move to the harder ones?”


If you and Russ Emanis want, I can send the CAD drawings (blueprint) or the STL files to make a pair of OPRE Tilting engines for your Odyssey aircraft:



The weight saving, the cost saving and the range increase will be more than significant.


Or, when we have available a pair of reliable / tested OPRE Tilting engines, we can mail them to be used in your project.

Thanks
Manolis Pattakos

[joshuagore]

Hello Joshua Gore

Impressed by your work with Russ Emanis, as presented at https://joshgoreworks.com/portfolio/ody ... -aircraft/


You write:
“but I can't help but wonder, now that you have this compact power unit, why not use the easiest method available to prove flight, then move to the harder ones?”


If you and Russ Emanis want, I can send the CAD drawings (blueprint) or the STL files to make a pair of OPRE Tilting engines for your Odyssey aircraft:

https://secureservercdn.net/166.62.112. ... 24x576.jpg

The weight saving, the cost saving and the range increase will be more than significant.


Or, when we have available a pair of reliable / tested OPRE Tilting engines, we can mail them to be used in your project.

Thanks
Manolis Pattakos

Well coming from you that's the biggest compliment i've received, i've been a fan of your work and browse your website just to learn new things often. I am actually working on other projects now as after I got Russ the station drawings he was on his way, that being said we talk and I will share this with him and make the contact. I know not everyone was into the electric and I know he has other plans for other aircraft for other customers so I am sure it will be a good connection. I could imagine the OPRE pushing that little bird and it would be beautiful.

Thanks,
Josh

[manolis]

Hello 007

You write:
"Thanks Manolis, I'll look into it."


The worst issue of the INNengine is the durability of the waving surfaces and of the track roller bearing surfaces.
Instead of dealing with variable timing or variable compression or ..., they should focus on the reliability.


There are secondary issues:

The "heavily" eccentric "third" track roller of each piston (that near the center of the engine) which cooperates with the inner (smaller in diameter) waving curve (2':55" in the video).

The heavy thrust loads (between the piston skirts and the cylinders) and the way they are taken.

Not to mention that an external blower is necessary for supplying the scavenging air.


In the video of Achates Power (page 187) and in the video of the INNengine (also at page 187) Aramco appears as the sponsor. Both are very lucky with such a sponsor; what I am jealous of is their testing beds.

Thanks
Manolis Pattakos

[manolis]

Hello Pinger.

You write:
“have you identified your market for this?”


There is not any such market, yet.
It will emerge when low-cost Personal Flying Devices will prove their reliability, range etc.
It will be for useful transportation means.

The JetPack market is oriented to re-creational vehicles, is in another class of cost magnitude, and right now they are trying to prove their usefulness.



For the electric Flyers:

read the interview of Mayman to Atlas News (https://newatlas.com/david-mayman-inter ... der/58822/),

also read the interview of Pat Symonds of F1 (https://www.motorsportmagazine.com/news ... -formula-e),

also read the pages 5 and 6 (Comparison to a battery powered personal flying device at https://www.pattakon.com/GoFly/DTR_1.pdf ).

To curry batteries in a car is a completely different case than currying batteries on the air.

Thanks
Manolis Pattakos

[manolis]

Hello Acula.

Rossy has a different opinion.
As he says, when he wants to go to a destination, he just turns his head towards the destination.

When the air speed increases, the aerodynamic forces on the head, hands and legs increase with speed square.

Have you seen how quickly Yves Rossy yaws?

Can Rossy control the “yaw” by “weight displacement”? How?


The guy who dances into the air (TunnelSport video) needs not any “weight displacement control”.
Even if his limbs / head were weightless, he would dance the same way, or even better: because the inertia and moments of inertia would be smaller.

Thanks
Manolis Pattakos

[J.A.W.]

Manolis - have you identified your market for this?


Electric. I can't see acceptance for anything but zero tailpipe emissions for city use...

Four seater. Who buys/drives a one seat car? Even two seat smarts never really sold.

Four seater. Anything above one seat means a pilot can be employed. Learning to fly solo flyer is going to be arduous, time consuming and thus expensive. A pilot alleviates that.

I can much more easily envisage a Hyundai four seat electric flyer with a trained/experienced, insured pilot and three passengers with their backpacks onboard in a city than I can an ICE powered solo flyer. Equally I can flip that for a farmer with a large area to cover (but he'll probably want to be able to carry tools - a drone can be used if it's only observation is required), or other rural applications so long as there's fuel. Is your flyer expected to be suited to both those environments?

Pinger, I'm sure Manolis will remind you that battery-electric is too heavy for a practicable
'personal flyer' type of rotor-craft - & that tiny turbines are too thirsty - likewise...

As for your wanting to upscale, motorcycles are (parts of the developing world - excepted)
generally used by a solo rider, whether for fun, commuting, or for direct work purposes,
& the small size means less space is occupied, both on road, & for parking, so I'd suggest
you are perhaps over-reaching with the call for a rotor-flight car.

[Pinger]

Pinger, I'm sure Manolis will remind you that battery-electric is too heavy for a practicable
'personal flyer' type of rotor-craft - & that tiny turbines are too thirsty - likewise...

And I will remind you that every European city is doing its utmost to eliminate ICEs.

As for your wanting to upscale, motorcycles are (parts of the developing world - excepted)
generally used by a solo rider, whether for fun, commuting, or for direct work purposes,
& the small size means less space is occupied, both on road, & for parking, so I'd suggest
you are perhaps over-reaching with the call for a rotor-flight car.

Hyundai - stupid?
Motorcycle - cross rivers, mountains?
Solo flyer pilot training - where?

[Tommy Cookers]

to be used for aerial work an aircraft must be certified in either or both the utility and public transport categories
even within an existing category of aircraft the cost of the above will be counted in millions/tens of millions
aerial work means getting paid or otherwise rewarded

most novel aircraft exist within the experimental category - this is far less demanding but doesn't permit aerial work
and such aircraft cannot be sold in fully-built form

aircraft mandated to be unreasonably light & associated pilot training etc both to exclude aerial work are less burdened

then there's the question typically of eg multi-million dollar public liability insurance or equivalent waiver