LET'S DISCUSS JETPACKS

I think if you put 2 in a backpack, you would have a sweet leaf blower.

>>944399
well it is very difficult to make your own turbojet engines.

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Jetpacks are a far way off. For full flight the fuel to weight is way off, closest would be the ductfan packs but thats not jets. The jets OP showed wont fly the fuel needed. Not to mention the rules, laws that literally keep us down. Hoverbike just started low untethered flights. Backpack helicopter guy still cant take off.
But if your intended to be touching the ground mostly. Mostly?
Jet bikes with airbag jumping suspension will soon be an x-games favorite in time.

>>944399
>jetpack
You mean leg remover?

>>944399
https://www.youtube.com/watch?v=f3AwBSwFV2I
Enjoy.

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>>944399
There was a jetpack that could fly for 23 seconds demoed at the 1964/1965 worlds fair.

http://srealserver.eecs.ucf.edu/chronoleap/288/

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>>944399
Warhammer jumpjets look like the fanpacks. But with all that bulk might as well go jet bike its not your going to walk that far. Good luck with the FAA.

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>>944439
Ok. Yeah. Um... Color me impressed. Thats a real freakin jetpack. The tech has no choice but to get lighter cheaper and safer. Ten minutes of flight time is about pic related performance and that was sci-fi! We live in a glorious time.

>>944441
this doesn't use actual jets like OP has pictured, if I remember correctly this used 2 chemicals that mixed and then expanded like crazy....

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>>944459
Same Co. new tech. They built a turbine pack that does what we think when it comes to jet pack. At 100 mph for ten minutes you could bug out from any situation. Man portable, fits in a car trunk runs off white gas.

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>>944465

>>944439
For the next best thing, tethered water jet pack
https://www.youtube.com/watch?v=pTBxESIZQg0
Surprisingly not crazy pricing, 30k is achievable for a lot of people... eventually.

>>944439
Is this slow enough to qualify as an ultralight?

>>944399
>>944399
>>944399
FUEL THE FUCKING PROBLEM IS FUEL!

>>944399
Just strap two solid rocket engines to your legs and ignite them. Flight will be achieved

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>>944501
>to your legs
I have a better idea

>>944399
I discussed the possibility of a drone hoverboard on /sci/ and they became contrarian as usual. Seeing as /diy/ is open minded enough to discuss jetpacks do you think there should be more research done on human lifting multirotors? One guy from Canada famously stood on his octocopter for 1 minute last year.

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>>944504
Maybe not multirotors in particular, but yes, I'd love to see more kinesthetically-controlled personal hovering platforms. I think it's very doable at the amateur-built level.

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>>944504
Hoverbike will be a thing soon.

>>944504
No. Human lifting multirotors* are just a meme. A multirotor 'hoverboard' has no practical uses.

*definition of multirotor means 4 or more propellors

>>944505
I want to build one with carbon fibre and the latest Japanese engines with servo-controlled vanes but two problems I have is a) how to set up a contra rotating mechanism and b) how the fuck to find a prop big enough.
>>944521
Ground effect
>>944633
That's what /sci/ said. I tried to put it through to their autistic brains that something doesn't have to be useful to be commercially viable. This thread is a perfect example in that jet packs have bee popular for decades despite being totally useless. Some people just want to blow money flying around like Green Goblin. It's a toy basically.

>>944633
yet Hoverboards are useless ( the one you see on snapchat) but they sell like crazy, lets not talk /biz/ or /sci/ keep it /diy/ ;^)

>>944685
>>944679
The question asked was should research be done on multirotors. In general you do research on stuff that advances your basic understanding of things and things with practical applications.

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>>944521

This is the sexiest machine I've seen in a long time

>>944753
That is totally uncontrollable. This is what I hate about kickstarter, designers spend too much time making their product look cool and not enough time making it work.
>>944734
You do research for whatever reason you want. There is clearly a market for hoverboards, jetpacks etc.

>>944774

If the center of gravity was below the props would it be controllable?

>>944753
That's the Australian one which has been around a few years but the designer's too big a faggot to actually try to fly it, right?
>>944774
It's controllable; some group in California built another one and proved it airworthy: >>944521

It uses a combination of weight-shift and movable vanes for control.

>>944804
Ok, so it's controllable, but will it ever get out of ground effect?

>>944874
whats the "ground effect" ?

>>944399
no, that doesnt make "like a hundred lbs of thrust" it will make between 40-60lbs at full power, comparing it to other micro turbines i have looked at.

also, you might say "well cool, 4 of them and im set". but you arent factoring in oil pumps, batteries, fuel tanks, and so on. these small fuckers are not the most efficient.

they have jetpacks with wings you jump out of planes with. just not a jetpack like what you are thinking of.

>>944883
If you are close enough to the ground you get extra thrust so it seems to work when it won't really if you take it higher. It is frequently used as an attack by those wishing to denigrate someone's hovering machine.

>>944891
The biggest issue is fuel consumption. Those things are so fuel hungry you will be needing your own body weight in fuel just for 30 mins of fly time.

>>944928
Why build one with a wing to utilize the ground effect. Like it start as a hover bike probably 4 rotors and as it increases in speed it relies less on the trust and more on the wing.

>>944891

Ok, then use slightly bigger turbines.....? I only used that picture because it is a tiny hobby turbine.

>>944929

I was anticipating between 5-10 minutes of flight time.

>>945021
Been done
https://en.wikipedia.org/wiki/Ground_effect_vehicle
>>945124
Well that has been done too in the video I posted earlier.

>>944874
>>944804
Huh? Those shitting things aren't controllable. They're barely capable of hovering for a little bit. That's it.

>>944891
Buddy? Its not a long thread. They are not long vids. Get with the rest of the class.
>>944439
>>944452
>>944459
>>944465
>>944468
Its happening! The thread is about /diy/-ing it ourselves. See its a thing, a real thing.
A real turbine powered man portable 10 minute 100 mph 10,000 ft JETPACK!
Now we want our own. Mwahaha...

Highspeed motors ramming air through a turbine fan stack riding on air barrings inside an air cooled combustion chamber burning vaporized refined kerosene. One on each side mounted to a universal joint articulated with pneumatic solenoids tied into a fly by wire control system/ aeronautics package.

Easy peasy?

>>945182
It's possible but legislation and cost is the barrier.

>>945190

>legislation

Oh yea, that bullshit that says "we can do it, you can't, get fucked".

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>>945182
you forgot the obligatory cool helmet

>Highspeed motors ramming air through a turbine fan stack riding on air barrings inside an air cooled combustion chamber burning vaporized refined kerosene. One on each side mounted to a universal joint articulated with pneumatic solenoids tied into a fly by wire control system/ aeronautics package.
What in fucks name are you talking about? Do you even understand how jet engines work

>>pneumatic solenoids
Wat. Despite the fact that 'pneumatic solenoids' are not a thing, pneumatic cylinders would be a poor choice for this

>> easy
No, making a jet engine that can spin at FUCKING HUGE RPM and not turn into a hand grenade is hard. To not melt itself into slag you have to make the turbine out of exotic materials like superalloys (expensive and a bitch to machine)

>>945564
Sounds like a perfect application for a Rockwell turbo-encabulator.

>>944521
I am getting involved in this hover craze, I see money. Shit all you have to do is hover three feet off the ground for a few minutes and it's guaranteed million youtube views. And just imagine if your machine actually managed to fly high and far. Problem is no-one will take me seriously when i say I want to make money off a hoverboard.

>>945564
Your burning need to admonish strangers has blinded you to sarcasm and humor. Its a common trait now a days, sad. However you showed me, good for you big man.

>>945591
The issue is that the people who see money tend to have a poor understanding of aerodynamics and energy consumption.

As far as travel goes, vehicles that take advantage of their forward-moving speed (such as airplanes) are the most efficient. In order for something to hover in place it has to be constantly putting out a certain amount of energy. This is do-able in a vehicle as big as a helicopter (Which still uses tons of energy, and therefore money) but when you scale it down to a personal level it gets difficult. Flight times are drastically reduced because you can't carry as much of whatever source of power you're using (fuel, electricity, etc).

All that coupled with the fact that hovering vehicles that don't take advantage of the Ground Effect can basically fly means that any real progress you made would get shut down pretty fast by any first world governing body.

Basically, with today's technology, people might like your product as a cool toy at first but when they realize it's pointless because it has a flight time of 20 minutes and it costs $100 in gas or five hours to charge they'll quickly forget about it and fall into some other dumb trend.

>>945865
Sorry, let me clarify something.

Vehicles like airplanes also have to be putting out a certain amount of energy, but a lot of that energy goes into it's continuous movement. With your thrust vectored upwards (such as in hovering vehicles), all of the continuous power is going to keeping you off the ground, and in order to move forwards or backwards you would need even more energy.

As cool as it is, it's a huge waste of energy. If we make a few breakthroughs in energy storage it might become a more realistic business venture, but even then you'd get heavily criticized for being inefficient.

I hope you find a way to do it though, 'cause I'd love to see a future where everyone has hovering/flying vehicles.

>>945190
>Legislation
In the US, if it's under 254 lbs unloaded you don't need a license or registration to fly it.

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>>944874
With more horsepower, sure (assuming it can't already - I wouldn't want to take that thing out of ground effect either until I've put >50 flight hours on it with zero engine failures AND have a parachute).
>>945163
It's totally controllable - weight shift (or "kinesthetic control") is very effective and natural for such lightweight powered-lift vehicles, and has been proven so on several different platforms since the 1950s including the Hiller Flying Platform and the Williams X-Jet. The same concept is being applied to these hoverbikes as well, in addition to throttle (of course) and control vanes for translation (total of 5DOF control; more than a helicopter generally offers).
https://www.youtube.com/watch?v=Gh5XWWXHVQk
They just need to build up the confidence, reliability and (perhaps) horsepower to take it out of ground effect and really let 'er rip.

>>945865
>>945867
You're just being negative, as someone else said the segways that everyone likes to call hoverboards are wildly popular despite being totally pointless. I think a hoverboard would be a tad more useful seeing as it can go places in three dimensions as opposed to two. a hoverboard that flew for 20 minutes and took 5 hours to charge that would sell like hot cakes. You said that people who are in it for the money have a poor understanding of engineering well likewise as your posts have shown those who presumably know about engineering are terrible at understanding markets.
>>945876
I don't think kinesthetic control is the way to go because flying car acceptance requires automation. This is another thing that the guy above has failed to realize; the fact that air vehicles don't have to follow roads makes them super easy to automate even at high speed. Literally you get in, say where you want to go and it flies you there.

>>945911
I think you're missing the point, I'm not saying that a functioning hover vehicle wouldn't sell well, I'm saying that the technology we have today isn't going to make a reliable product.The difference between this and the segway/hoverboard market is that for those the technology was basically already there and they're not already inherently illegal. The two main problems you'd face with hovering vehicles are energy consumption/waste and fighting whatever government you live under for their legal use in otherwise-illegal airspace. Right now ultralights are legal to fly as long as it's not above people, buildings, and towns, and only in specific flight paths, but something like you said in your second response (Autonomously flying to a destination) would mean that you're probably flying into town somewhere.

If this is something you want to invest your time and money in, please do. Few things would make me happier than to be able to fly my own vehicle into town, there's just a lot of things you need to think about besides just the marketing aspects of this if you're going to take it seriously.

>>945911
>acceptance
Who gives a fuck about acceptance? Unless OP wants to fly over urban areas, he could just fly under Part 103 rules, which already have all the "acceptance" you could hope for.

sent a link to this threat to collin furze the masrter of pulse jets

>>945980
Tfw as a young teen me and my buddies would fly beginner level model rockets. We had an Air force base in town (happened to also be the headquarters of strategic air command). We always flew in the fall in farmers fields after harvest on the opposite side of town away from the flight path of the runway we're talking like 15 miles away. And we still got tracked down by SPs and told to knock it off several times. Even in the late 90's, early 2000's they acted like the cold war was still going on.

>fuck off you have no jurisdiction here, is it that boring around here?

Granted we were within a few miles of something. Theres no reason for a giant "rundown" warehouse in the middle of a farmers field. Rumor has it was an off site back up nuclear power plant for the underground command center on base

>>945564
pneumatic solenoids are a thing though very common in fact

>>946911
Pics or it didn't happen

https://www.youtube.com/watch?v=x2sT9KoII_M

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>>945564
>>946948
>What in fucks name are you talking about? Do you even understand how jet engines work
Anon's post was rather gibberish-y, but it does seem like he has at least some idea of how they work. That said, I certainly wouldn't strap on a jetpack made by a man who talks like that.
>'pneumatic solenoids' are not a thing, pneumatic cylinders would be a poor choice for this
Pneumatic solenoids are solenoid-actuated pneumatic valves. Most guided missiles and ejection seats employ pneumatic solenoids fed by rocket propellant gasses or a separate gas generator, so it's not something that would be THAT out of place on a jetpack.
>No, making a jet engine that can spin at FUCKING HUGE RPM and not turn into a hand grenade is hard. To not melt itself into slag you have to make the turbine out of exotic materials like superalloys (expensive and a bitch to machine)
http://docslide.us/documents/kurt-schreckling-gas-turbine-engines-for-model-aircraft.html
If you're willing to tolerate low ITTs and the poor(ish) performance that entails, it's possible to make a turbojet without doing any machining at all. Pic and book related.
And yes, that compressor wheel IS made of wood.

>>946951
this samefag

>>944399
>trying to make a jetpack with turbines
nah m8 take the turbine and mount it on a bicycle

>>947010
>> that compressor wheel is made of wood
OP is wants to make a jet pack, you sure as fuck ain't gonna make one with a jet engine that gets poor performance

>>947010
>wooden turbine
ayy lmao

>>944399
The problem with DIY jetpacks is if you dont know what you're doing, you die.

>>947296
true for many /diy/
so i guess everyone who tried so far either didn't knew what they were doing or are flying around and don't want people asking about it

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Actually it's easy to make a jetpack with around 30-60 minutes of flight time.

The issue is getting a compact turbofan. Turbojets burn too much fuel at low speed and the RC plane turbojets are even worse as they have radial compressors like a turbocharger which are less effective.

The best off the shelf engine is the one used in the tomahawk missile. If there was a cheap open source turbine with similar specs you could easily build all kinds of jetpacks and vtol vehicles.

The worst thing is there's a few home made turbines that are similar but the turbine hobbyists are autists and don't open source things. They build them, take a few videos of it running on a bench then put it in their garage never to be used in a vehicle.

The flying pulpit used a tomahawk motor and had about 60mins flight time. It was basically a flying segway.

Existing turbine companies won't develop cheap compact turbines because they make so much money selling 1970s designs to military at highly inflated prices. If they build a cheap commercial turbine they can't really sell old ones to the military for hundreds of thousands per tomahawk.

You could probably get the turbine hobbyists to go open source if you got a decent project underway and tempted them with cheap parts from mass production.

>>947888
>Turbojets burn too much fuel at low speed
How much is "too much?" Seems subjective to me. And most simple turbofans still have more than 50% of the fuel consumption of a simple turbojet, and will generally suffer the trade-off of having poorer thrust:weight as well. And any turbojet you use is going to be head-and-shoulders beyond any rocket or pulsejet in the fuel-consumption department.
>the RC plane turbojets are even worse
Sure, single-stage turbojets with resulting low pressure-ratios are fairly crude.
>radial compressors like a turbocharger which are less effective.
Wat
Centrifugal compressors perform wonderfully in terms of efficiency, pressure ratio and cost. Their major drawback is their form-factor, which includes a broad cross-sectional area that can add considerable weight and bulk particularly when attempting to design multiple centrifugal stages. But even so, most modern turboprops and even the Williams turbofan you mentioned still employ one final HP centrifugal stage behind a handful of LP axial stages.
>The best off the shelf engine is the one used in the tomahawk missile.
I'd argue the Czech-built TJ-100 family is a far better starting point these days.
>The worst thing is there's a few home made turbines that are similar but the turbine hobbyists are autists and don't open source things.
The fuck are you talking about? Did you even look?
http://www.john-tom.com/html/Jet.html
>The flying pulpit used a tomahawk motor and had about 60mins flight time.
More like 40.
>Existing turbine companies won't develop cheap compact turbines because they make so much money selling 1970s designs to military
See above - there are a few recent offerings coming out of Europe. But the civil small-jet market frankly isn't very big, so it's no wonder that the majority of engines of this size would be developed with military cruise missiles and target drones in mind.
>highly inflated prices
For a sophisticated twin-spool, ~15:1 pressure-ratio turbofan? Nah.

>>948268
This guy has a 6 stage axial home made turbine. I think if a decent effort was made to find a way to make them with the latest additive manufacturing methods and recently developed materials decent turbines would come down in price.
https://www.youtube.com/watch?v=pXDNMv9t990

>>944465
His legs and shoes are burnt to shit.

>>948312
Yes his Nomax flight suit is doing its job.

>>948311
>This guy has a 6 stage axial home made turbine.
Pretty neat, but you really think it's any more practical than a centrifugal-flow turbojet? Seems like a lot more manufacturing expense (and not to mention, complication wrt the variable stator) and reliability risk for little to no appreciable performance gain. His thread states only a 2.3:1 pressure ratio is projected (and that's right against the stall line, to boot); centrifugal compressors can achieve this easily in a single stage, and they can do so dependably without needing actively-variable stators.
>I think if a decent effort was made to find a way to make them with the latest additive manufacturing methods and recently developed materials decent turbines would come down in price.
Are you fucking kidding me? No way your meme-manufacturing methods are going to help here. 3D printing's strong suit is in rapid prototyping; for mass production, casting and forging will always be more economical. And if you're thinking of /diy/ or cottage industry level production, you can forget about it, since metal-sintering 3d printers are expensive as fuck.
>>948312
>>948445
They should add afterburners just for keks.

>>944399
As has been mentioned, the problem with jetpacks isn't in the technical work, we have the know-how, it's in the fuel.
There isn't a fuel source on earth with a high enough density/power ratio to make it work.

If we had modded minecraft-esque flux capacitors or some shit, able to style ridiculous amounts of energy and discharge said energy at an acceptable rate, all in a small package, we'd all be zipping around in jetpacks right now.

>>948491
But your wrong because it is happening for real already.

https://www.youtube.com/watch?v=HZRp6iRjnhQ