Be the first on your block to have one

Like many science fiction concepts, the jetpack design has become firmly entrenched in the collective psyche: ask anyone to draw you a jetpack and they will give you a man with two fiery pods strapped to his back gravitating him skyward.


The Jetpack is constructed from carbon fiber composite, has a dry weight of 250 lbs (excluding safety equipment) and measures 5 ft high x 5.5 ft wide x 5 ft long. It's driven by a 2.0 L V4 2 stroke engine rated at 200 hp (150 kw), can reach 8000 ft (estimated) and each of the two 1.7 ft wide rotors is made from carbon / Kevlar composite.

http://www.businessweek.com/lifestyl...rss_topStories

http://www.martinjetpack.com/the-martin-jetpack.aspx

Wow, I LOVE the control assembly, the fins in shape of an X below the fans, near your feet, genius. Looks much more stable than anything else I've seen like this. With that level of stability this might actually sell.

Wow looks awesome.

That's really cool. I wonder if they could make it lighter by using a smaller engine to drive a generator, and then use the generator to power two electric motors.

Very cool - but shouldn't they call it the Ducted-Fan Pack?

...or maybe the Fan(ny) Pack? ;)




I'm no engineer, but I think the hybrid solution would end up being heavier and more complex than the current setup.

But 8K feet? How'd you like to be the dumbass appointed as official specs tester for that shit? I'd much rather be the guy that gets to test the 30 minute runtime part, 3.5 feet off the ground while chasing neighborhood cats, sparrows or Jessica Alba around.

It's only the last hundred feet or so that kills ya.

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Originally Posted by Version3

But 8K feet? How'd you like to be the dumbass appointed as official specs tester for that shit? I'd much rather be the guy that gets to test the 30 minute runtime part, 3.5 feet off the ground while chasing neighborhood cats, sparrows or Jessica Alba around.

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I'd MUCH rather be the guy at high altitude. If you're 3-10 feet off the ground and have an failure in the controls or engines, you're probably going to be hurt pretty badly. At altitude, you have time to pop the parachute.

EDIT: Holy cow, down to $86k and dropping? If I ever have the money I'm grabbing one.

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Originally Posted by cam76034

It's only the last hundred feet or so that kills ya.

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Actually it isn't the fall that kills you... It is the abrupt stop at the end.

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Originally Posted by trickyrix

I'm no engineer, but I think the hybrid solution would end up being heavier and more complex than the current setup.

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I dunno, a single-cylinder engine can power a generator that puts out enough electricity to run a small house. If something about the size of an automotive alternator, maybe a little bigger, could put out enough power to drive the fans, you wouldn't need much more than a lawnmower engine to drive it.

200 hp seems like an awful lot to run something so light. World War I era fighter planes had around 100-180hp and weighed four or five times more than this ducted fan pack. Of course, they didn't have VTOL capability, but still.

Oh, and 8,000 feet is a lot safer than 100 or so. At 8k, you've got plenty of space for a 'chute to open.

I bet that wouldn't be too fun in a storm. Kinda kills the commuter capabilities in areas of unpredictable weather.

holy crap! what can I sell....

How fast does it go?

What could possibly go wrong?

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Originally Posted by Dudley Dawson

200 hp seems like an awful lot to run something so light. World War I era fighter planes had around 100-180hp and weighed four or five times more than this ducted fan pack. Of course, they didn't have VTOL capability, but still.

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Pilots or engineers can correct me if i'm wrong, im still in community college and all...but the super light WWI planes only had to accelerate horizontally up to about 60 - 100mph for the wings to generate enough lift to get the plane off the ground, and at full power they were very prone to stall if you pulled back too far on the stick. You would need a far greater amount of power to achieve vertical lift like a helicopter, hence the 200hp gas engine. Just look at the differences in power requirements of turbine powered jets verses large saturn IV style rockets.

A two stage gas/electric hybrid solution might have benefits from better power delivery or being able to have one engine per propeller, but I think power to weight would end up somewhere around the same.

Yeah, that's why they were biplanes. The motors weren't powerful enough, so the planes needed more lift. A lot of them topped out at a lower speed than our Miatas.

I don't know if the hybrid setup would be lighter, but it is something I'd wonder about were I building something like that. Another benefit (I'm guessing) would be better range, since you can constantly run the gas engine at its most efficient RPM instead of having to accelerate and decelerate it.

The electrical power needed to run a large ducted fan is enormous, and they're also very inefficient compared to propellers. But, they're needed in this design because of size considerations and to keep from chopping the operator's head off ;)

I'd much rather be running an efficient gas engine. Electrical power is just starting to take off in lightplane design, and it's nowhere near the point of powering something like this although it's improving rapidly.

You can actually see the difference on a small scale with RC planes. One of my planes with an average electric motor and propeller will fly about 8 minutes on a 1300mah battery... an EDF (electric ducted fan) jet the same size and weight lasts about 4 minutes on a 2200mah battery. As weight goes up, power requirements increase exponentially, to the point that the largest hobbyist EDF system is only 140mm in diameter and uses 12 cell (2 parallel for a total of 24 cells) lipo batteries that weigh over 6lbs in a plane that spans well under 6'. Granted, it's better than the old Nicad batteries, but we have a long way to go.

I'm sure that these and other "faux jetpacks" will eventually be electric, but it ain't happening right now. Gas has a big power to weight advantage at the moment.

Oh I wasn't suggesting that 100 feet would be safer than being over a mile up.... I was saying I want to be at neither height with a motorcycle engine strapped to my back.


I'll be interested to see where the limitations end up by the time you can have one delivered as a consumer in the US. With a license, obviously they could just use regulation to limit altitude, and it would work reasonably well. With the general public; people with more money than sense? I'd think they'd have to build in that limitation.