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Who wants to build a real Jetpack?

Who wants to build a real Jetpack?

Who wants to build a real Jetpack?

Hello everyone!

My name is Toni Langer and I’m 23 years old. I’m a trained electronics technician for devices and systems and I have a project that I’m currently working on: I want to build a jet suit! I’m looking for people who are passionate about this project and want to collaborate with me.

Richard Browning with his company Gravity Industries and several others have already shown and proven that it’s possible! I think we can do better and together we can construct something that is intuitive, stable, and safe to control.

I live near Berlin and I’m specifically looking for people who have experience with small engines for model building and corresponding software, as well as proficiency in CAD software. If you have these skills or know someone who might be interested, please don’t hesitate to contact me.

https://www.linkedin.com/in/toni-langer-111840245/ 1

Here’s my basic concept:

I want to create an easy and intuitively controllable apparatus that can hover and transition into flight at will. Think of a drone (as an object! I do not plan to arrange jet engines squarely around me), the drone itself knows much more about its current situation than you could possibly keep track of. It knows its exact location and orientation and it constantly balances itself in midair. With your remote, you basically just tell it in which direction you want it to go, and it flies itself in that direction. I want to develop a jet suit that incorporates this concept. Not having to worry about how to fly, only where to. Eliminating the need for elevated upper body strength and extensive training sessions.

So why model engines?

Well, the term model engine may be a bit over specific. Small engines that are not intended for model building but have a similar size are also available. But generally, they provide the most thrust in the smallest form factor. The market is established and will not disappear anytime soon. So spare parts will continue to be available. Additionally, they can be operated with a variety of fuels. The most common is kerosene, which is easily obtainable. So they, and in a broader sense the jetpack, can be operated with readily available fuel that doesn’t tend to spontaneously ignite.

Why not EDFs?

For one, because they don’t provide enough thrust individually, so you would have to bundle a large number of them together to generate the necessary thrust. This creates a certain redundancy, which would be good. But another crucial disadvantage is the energy density of the batteries. The battery pack would have to be incredibly large and therefore heavy to ensure decent flight time. This would in turn require more EDFs. The whole thing would quickly become extremely cumbersome and impractical. Another disadvantage is that, unlike the fuel tank, the battery pack does not get lighter when it discharges, but rather maintains its weight. And I think we’ve all seen videos of what happens when such a battery shorts internally.

Of course, the idea of a quiet jetpack that can be easily charged at an outlet and offers a high degree of engine failure safety is tempting. But I think the disadvantages outweigh the advantages here. If I have the choice between strapping 10L of kerosene or a 200-cell lithium-ion battery that draws several hundred watts or kilowatts from my back, I’d rather take the kerosene. And let’s not even start with rocket engines… highly toxic and flammable fuel, special and heavy tanks necessary, poor fuel availability, etc.

I have noted the following questions and issues:

• Danger from fragments of spontaneously disintegrating engines
• Normal operation of the engine susceptible to small air bubbles in the fuel line
• Insurance? What to do in case of personal injury?
• Legal requirements for approval?
• Test site?
• Patent protection? Which solutions are even worth protecting?

This list will probably grow enormously! Please think about everything that can go wrong and write it down here. I want to get an overview of the most pressing issues so that we have kind of a bucket list that we can then solve point by point.

A few words about marketing and sales.

I don’t think there are many people who would buy a jetpack for 500k or more. However, I believe there is a huge market for people who want to fulfill their dream of flying with a jetpack for a day. What is missing is a device and a location that allows this to be done safely. We can discuss what the flight location should look like when we get there.

The project will be financed by me in the beginning, so don’t worry about that.

I would be very happy to hear from you and I hope that we can create something great together!

Best regards,

Toni L.

RE: Who wants to build a real Jetpack?

I'd start with 1/2 scale or 1/4 scale, you can go with electric and tether to a battery for limited range for hover testing to perfect the control system and interfaces.

A jet suit is something you wear and become the structure for - that won't be something that can be computer controlled.

A jet/rocket pack has it's own structure but usually use weight shifting for steering/guidance. I don't know if they have the ability to turn in place or if it is just a long banked turn from weight shift.

A drone is something a person would ride on; they can't make significant CG shifts to affect steering/guidance.

For the most part propellers have the best coupling to the air - hence the large number of multi-rotor drones and on helicopters.

An excellent compromise has been the turbo-prop. A nice combination of the high power density of the turbine engine and the low power density for coupling to the air via the propeller. This is how the V-22 operates, though it adds tilt-rotor. One could make a hybrid where 90% is supplied by the turboprop and +/-10% added by electric motors for vertical rate control.

A concept I have seen is using a drone platform with the payload suspended from a cable. It keeps the passenger/cargo some distance from the sharp or hot parts.

RE: Who wants to build a real Jetpack?

Thank you for your input!

Based on the definition you gave for the different terms I want to build a Jetpack. The drone with the cable is also a good idea but not what I have in mind. I want to mount the engines on the tips of two wings that extend from a fuel tank at the center of my back. The engines are mounted at shoulder height so that your lower body acts as a passive stabilizer. I’m also planing to bring some kind of ballistic parachute into that thing at some point but… let’s solve the problem of getting that thing of the ground first before we make it safe for great heights.

RE: Who wants to build a real Jetpack?

Pendulum stability only works if the pivot is fixed to the ground. When applied to a free-moving item it tends to destabilize the system unless the operator actively shifts their weight relative to the lift/propulsion system.

There have been many variations on this already.

RE: Who wants to build a real Jetpack?

Yep, will be a hell of a balancing job for the computer and actuators to perform to stabilise the pilot. There are a lot of factors going into flight stability. As the fuel tank gets lighter and lighter during flight. The center of mass will move closer and closer towards the pilot. But, even with the whole construction on my back, that distance which the CoM will move won’t actually be thaaat big. I’d guess roughly 30cm or 1ft at an absolute maximum. The solution that came up with in my concept is that the carrier arm which connects the center fuel tank on my back with the engines is a hollow metal structure which can vary in length and is slightly angled forward towards the pilot. This way the center of thrust can be either held on the same plane as the CoM or even be moved before ore behind it for more rapid flight transitions. For example, the CoT could be moved behind the CoM to automatically tilt the pilot forward in a more suitable position for higher speeds and then moved before the CoM briefly to help rotate the pilot in the other direction faster to decelerate. I also want to mount the engines on a gimbal and incorporate movable thrust guides to control the thrust vectors. Together with the adjustable wingspan, that will give us multiple ways to manipulate the orientation of the pilot and direction of flight. The fastest being the thrust vectoring through controllable air guides, I want to use this for automatically controlled micro adjustments of the Thrust vectors to ensure a stable hover flight without the need of any input from the pilot. Another way, yet bit slower, will be to orient the engines in different directions (forward, backwards, straight down and away from the pilot) through the use of a gimbal construction. Of course varying the thrust output of the engines themself by regulating the fuel flow rate will be also in cooperated. And the last one being the mentioned interplay between CoM and CoT by manipulating the wingspan.

RE: Who wants to build a real Jetpack?

Are You interested in this kind of flight... or greater experience?


Regards, Wil Taylor
o Trust - But Verify!
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation, Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", HBA forum]
o Only fools and charlatans know everything and understand everything." -Anton Chekhov

RE: Who wants to build a real Jetpack?

Like I wrote, the engines are not fixed in one position and the thrust can be directed and controlled with multiple methods.

RE: Who wants to build a real Jetpack?

OH, I see cried the blind man.

Any Idea How many years and $$ the current 'GRAVITY' design took to evolve?

This is not a trivial or inexpensive task.

Regards, Wil Taylor
o Trust - But Verify!
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation, Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", HBA forum]
o Only fools and charlatans know everything and understand everything." -Anton Chekhov

RE: Who wants to build a real Jetpack?

I never thought that it'll be easy. My goal is to become a competitor to gravity. Of course the developement will consume enormous amounts of money and years of time but that's not gonna to stop me from doing it.

RE: Who wants to build a real Jetpack?

I mean Richard browning also started from similar grounds.

RE: Who wants to build a real Jetpack?

And because it will take a long time, it's better to start sooner than later. A smaller-sized prototype won't consume that much resources to build and is a good start to test the concept.

RE: Who wants to build a real Jetpack?

And exactly what experience do you have in aviation...? Regardless... here are some Fud-4-Thot.

Insight is the first condition of art." -- George Henry Lewes

insight comes thru experience...” --Fr Kenneth

Art without engineering is dreaming. Engineering without art is calculating. --Steven K. Roberts

Personal experience.
in the 1980s I was the USAF lead engineer on the smallest attack aircraft ever operated by the USAF: A-37B. After about a 2-years I told my wife I could outline the design of the greatest next-gen small attack jet like the A-37... but a true ass-kicker!... after all I had about 7-years under my belt! "Honey give me 6-to-nine months to get it laid out and written down."
Two years later and tall stack of handwritten draft I had the jet figured out... and learned humbling lessons about aspects I had no clear ideas about. The experience of that study ignited my furious study of all aspects of military aircraft... and made me fearless... understanding what You don't know is key to unlocking what You have to know. And never forget human rated flying machines are far different from UAS. Every humans' body is pink on the inside... and I have seen the insides of humans spread-out, and sometimes erased in the 'red splash' at high impact speed. BE FEARLESS... fly your own machine to learn your own machine!!

PS: these guys, also young-guns, want to be revolutionary innovators in light aircraft... mostly exotic composite structure slick-aero design... https://www.darkaero.com/ . I think they still have many unknown hard lessons to learn... so I made a few unsolicited technical comments... and received a very confident reply back saying, 'thanks, got all those covered'... I hope they do.

"At that time [1909] the chief engineer was almost always the chief test pilot as well. That had the fortunate result of eliminating poor engineering early in aviation.” – Igor Sikorsky

Regards, Wil Taylor
o Trust - But Verify!
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation, Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", HBA forum]
o Only fools and charlatans know everything and understand everything." -Anton Chekhov

RE: Who wants to build a real Jetpack?

I don't have experience in aviation that is the whole reason why I have opened this thread inside an engineering forum. To find people with experience and whiling to invest a bit of time.

RE: Who wants to build a real Jetpack?

What I wanna do is actually quite similar to these water jetpacks.

RE: Who wants to build a real Jetpack?

How Gravity Built the World's Fastest Jet Suit

World's First Electric Jet Pack Is FINALLY Here!

This is a taste of the sheer development effort and trial/error... and incidents... and design-team in various technologies... by older heads.

Regards, Wil Taylor
o Trust - But Verify!
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation, Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", HBA forum]
o Only fools and charlatans know everything and understand everything." -Anton Chekhov

RE: Who wants to build a real Jetpack?


I think it could be worth taking a closer look at the structure itself. It may be suitable to be reused as the core structure o hold the fuel tank and engine carrier arms. Gonna do some research on that.

Additionally, Mario from Frank turbine got back to me and confirmed the release of the TF-1500 for the end of 2023. I was a bit surprised that the owner itself answered me but why not. I also asked him whether or not it would be possible to rent the engine and if he could send me some cad models to which he replied that they never thought about renting these out but that the cad models wouldn’t be an issue what so ever. Well… he didn’t send the models yet even though I send him another mail to which he repeatedly replied and ensured that it would be possible to do so. He also stated that the price for one engine will be 50k€ to 80k€. Quite a bit higher then the roughly 27k€ for Jetcats P1000 engines. Jetcat never replied to my request whether or not they rent out engines. But at least I already have the cad models for the P1000 and P550 and P400 from an earlier request that I did in 2019.

RE: Who wants to build a real Jetpack?

I suggest you start with a prior art survey and put together a table of equivalent machines. https://en.wikipedia.org/wiki/Jet_pack Since these things already exist in various forms you'd need to identify what your idea offers that theirs doesn't - it sounds like the control side is one of your interests, I agree adding error inputs (offsets) to a stable rig is going to be easier to fly. I've been involved with a few different ground up designs of various machines, and if you don't know what has been done before you are going to spend a lot of time relearning known art.

Westheimer's rule is always applicable.

A very simple spreadsheet model will help with motor selection. You'll have to balance fuel consumption, flight time, mass of the pack, and occupant mass, for each different engine type. If you can bear to go to a turboprop (or high bypass ratio turbine) you will massively improve your static thrust/fuel consumption figure.

That's the fun bit. The boring bit where you will fail in 99% of cases is the business plan.

Back to engineering - are you familiar with the product development V?


Greg Locock

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