f13.net

Not sure if I'm posting this in the right forum, but I saw this via CNN and lololol, it looks awesome:

http://jetlev.com/

Basically it's a water pump that pumps water into a jet-pack that you wear on your back.  The pump is attached via a thick hose.  You fly (jetpack style) while the pump is dragged along behind you. 

I'd embed the youtube video but I suck! 

http://www.youtube.com/watch?v=7-KczCp0OQ4&feature=player_embedded

That's a redneck hold mah beer and watch this moment waiting to happen.

Or a college binge drinking EXTREME BEER BONG

Looks very energy intensive. I wonder what sorts of operating times they are getting compared to the diminishing rate of returns on having to carry to much fuel.
But man it looks fun!
 :grin:

Are you... you have to be joking, right?

It's attached to a boat and uses the equivalent of an oversized pulsejet (similar to what a jetski uses) to force water up the tube from a boat on the ground and then through constricting nozzles on the backpack. I suspect the operating time is measured in hours, just like a jetski, since the engines and attached fuel tank are on the tethered boat.

CNN is late to the party, Fallows posted this nearly a year ago:  here (http://www.theatlantic.com/technology/archive/2010/03/finally-a-flying-device-too-wacky-even-for-me/37783/)

Of course we were all supposed to have one of these by now.  It is funny to note they've removed the list of banned maneuvers from their website.  Still a super crazy way to fly - can't wait until it starts sucking up swimsuits and small children en mass.

No, it says its attached to some kind of floating platform it has to drag around with it as the person is moving horizontally across the water, which I would guess would create drag on the system?


As for the engine, yeah it seems it is comparable to a jet ski in the 250hp range. Wow I never knew you could get that kinda of thrust out of one of those.
Sorry Im not an engineer so I was curious about how it all worked but didnt have time to look it up myself. Just be honest in my own ignorance.

I wonder what happens if you get your foot in the way of one of the thrust nozzles.

In horizontal movement mode the 'drag' of the tethered platform will be fairly minimal compared to the overall bulk of the operator plus the backpack. However if you're using it to move in the water then basically it's an inefficiently shaped jetski.

When moving vertically then the only real additional overhead is the weight of the hose filled with water - which is still a lot less than a usefully sized fuel tank would be. There will be some resistance when moving forwards from the tethered module but it's going to be minimal.

I smell a DIY projekt.

Not much.  A jet ski impeller assembly is built more for high flow than pressure.

I had a napkin design long ago for this same concept, only I flew underneath the water instead of above it.

You invented a submarine?

He did say it was long ago.

Like before the Civil War, long ago?

If you're talking about the English Civil War, you'd be right: http://en.wikipedia.org/wiki/Cornelius_Jacobszoon_Drebbel  :grin:

DIAF.  :oh_i_see:
Yes, basically a submarine... but one involving propulsive surface supply (like the jetlev), rather than just e-power.   The 'tow-bouy' would house the pumps and the sub would fly along w/o need of an engine space (which increases dryspace, buoyancy, weight, etc.)  Not very practical obviously, since the drag created by the umbilical would negate any real speed/power gains.  Similar to an oilrig ROV I guess.

Yes but wouldnt it decrease the cost?
Give me a 30-50' umbilical so we could some real depth out of it and I'd buy it.

That is an awesome idea! Did you ever look at raising capital for a pre-production build?
While the economy is in the shitter for most people stores aimed at the more affluent are reporting record gains and a toy like this would fit well within that market segment.

I actually have thought of prototyping one, but I'm what you call a "normal dreg of society."  That is, I have to work for a living and therefore have little time to see my ideas to fruition.  I have a few potential angel investors for various projects I've lined out, but they're too close to me personally to allow failure.  Such is life.

As for that particular design, it's almost better to simply have a surface generator feeding power to a normal "trolling motor" thrusted sub.  The umbilical is smaller diameter, less drag, more control, etc.   Regardless, designing and building a 1ATM submarine is not easy. (I have reams of info. on the subject including a few hard to find books on subsurface oceaneering)  Most wealthy folk I've approached with the idea are too afraid also, even with a production quality minisub around $1million.  

A sub using a surface-supplied hydraulic pump would really just be to haul ass in circles, do tricks, etc.  Just like the jetlev.  Not really designed to go anywhere 'smartly.'  <--heh, naval term

edit:
Y'know though, a giant underwater hydraulically powered Mech would be worth designing though!

When you say $1 million do you mean to create a prototype or was that what you were thinking the retail price would be?

Because the first is doable the second not so much, not for the design you've discussed.

This company is producing a high speed personal submersible watercraft with a retail price tag of $68k.
http://www.seabreacher.com/seabreacher-j

Problem is they have a maximum depth of 6' which sucks ass.

Doing a quick google search seems their are a number of companies making submersibles for the affluent some with diving ranges to 300' and price tags of only $2 mil.

I would aim for more of the recreational crowd. Something likes this but faster and less of a toilet combined with phone booth look, but the price tag is right. http://www.gizmag.com/go/3396/picture/6764/

Wonder what the liability would be for a company making a personal underwater jetski? I'm seeing a lot more potential for people running into stuff underwater than above water.

You can get a 1atm mini-submersible for between $800k-$1.2M that'll get you between depths of 400-1200ft.  The deeper you go, the more 'spensive it gets.  These subs are all pretty much designed to go on the back of a moneyhat's superyacht.  The price I gave you was for one of those, which actually isnt that bad.  

The 'Seabreacher' is issentially an enclosed ambient jetski, not a 'submarine.'  It'll go 6 ft down for a few seconds (while the inside floods with water mind you) and then you pop back up.

In re. hydro/jet-ski sub, there are many applications for such a tech., including recreation, but mostly for doing subsea work for long hours in hostile conditions.  Most of these oilrig ROVs use electricity to run their thrusters and hydraulics only for tools.  It'd be interesting to see what'd happen if they used solely hydraulics.

To give you a better idea, I've always wanted to build the Seaquest 'Stinger' minisub, but could never figure out how to get that much power w/o somthing like a small Halfnium reactor in the back.  So screw it, just tether it to the ship, maybe even hydraulically.  Or better yet, stick a small-block volvo or yanmar diesel in a tow-bouy with a crash pump and let 'er rip.

If I recall, one sub. project for an old friend of mine (he was buying one for the boat) failed when the lead engineer perished during the testing phase.  This was back in the 80's.