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Jet engine

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Thread replies: 34
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Is it possible to make jet engine in home? I mean something that would have some power.
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Of course. There are many on Youtube and I suppose many more not on Youtube
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If you have to ask the question you don't have the skills.
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>>914090
does your home have a machine shop? Are you willing to buyfag all the complex components you have no hope of machining? Then yes you can do it!
http://www.jmaireland.com/build%20your%20own%20turbine.pdf

http://www.john-tom.com/html/Jet.html
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>>914090
Enough to move you a significant distance? More than likely not, unless you are experienced in that kind of engineering and made of money to buy metals that can take the heat. And you have a machine shop to fabricate the parts to the exact specifications. If you're talking enough power to move a few lbs, then sure, tons of stuff on youtube.
There's an english plumber on youtube who makes incredibly crude rockets and straps them to bikes and buggies and stuff, and they usually break down after the first use. I think his name is colin fruze
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>>914090
do you want to build a jet engine for the fun of it? or are you looking for some form of easily produced jet propulsion? because if it's the former then go for it.. if your more interested in the latter then look up pulse jet engines... no moving parts, super simple to make, and provide reasonable thrust vs the effort to make..
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>All these naysayers
OP, go hunt down the book "Gas Turbine Engines for Model Aircraft" by Kurt Schreckling. It explains how to build your own simple single-spool turbine engine (pic related) with a single-stage axial turbine wheel, cut+bent+ground out of a slab of ordinary sheet steel with basic tools, along with a single-stage, centrifugal compressor of wooden construction (I shit you not). It's crude as fuck but it does work.

Alternatively, pulsejets are even easier to make but a lot more troublesome to use due to their deafening loudness, finnicky ignition and a plethora of other issues. But if Colin Furze can do it, it can't be that hard.
https://www.youtube.com/watch?v=bCsg5pQimWI
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>>914309
this its a lot easier making that compressor stage than a machined impeller
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>>914311
Just had another idea; you could also probably get away with cannibalizing the compressor from a junkyard/craigslist-special leaf blower.

Or fuck it, just make your own motorjet by sticking a combustor in the tube of a leafblower. This vid shows one way of making a simple combustor (the project itself is something of an electric motorjet):
https://www.youtube.com/watch?v=yKuq8T7KMa0
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Look up smart film projects on youtube.
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>>914315
Yup found these in blenders
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>>914309
you can make a jet engine that works (for a while) but normal steel has way too much creep to work well--either to put out a lot of power, or work for a long time.
Especially if you make a rotor by cutting slices in a flat disk and then bend the rotors to get them tilted.... At the high RPMs that an engine needs to run at to make a lot of power, the sheets tend to flatten out again.

The real jet rotors are made from nickel-steel alloys like Inconel. Mcmaster-carr sells pieces 6 x 6 inches and .25" thick for about $150.
(this is also what they use for turbocharger rotors and turbines)

IF you could get holes drilled in pieces of this stuff to join it onto a shaft (that it wouldn't spin on) then you could grind the blades by hand using a dremel & diamond cutoff wheel. Gonna take a while tho.
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>>914529

What if he finds a ruined turbo car, truck, generator, boat, whatever and pulls off the snails?

Kind of buyfag'ish but he gets one step ahead without the precision machinery.
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>>914529
>normal steel has way too much creep to work well
Not if you heed it's temperature and stress limitations. The book covers all of this. The pressure ratio of such a crude engine is fairly low (temperature rise during compression is only about 30 degrees), so you actually can achieve respectable fuel flow and thrust before you exceed temperature limits. It's not particularly efficient, but it works.

You don't NEED a fancy expensive Inconel turbine wheel to get a turbine engine to work. It will perform better if you do, but it will also be a shitload more costly.
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>>914546
>What if he finds a ruined turbo car, truck, generator, boat, whatever and pulls off the snails?
I tried this once and found it difficult to find any salvage turbos that weren't already totally ruined. So you almost have to buy a salvage/pull or a new unit.

The next problem is that the casings are way thicker and heavier than you want, and there's no easy way to change that or build new ones.

The last problem is that turbos are really the opposite of what you want for a jet engine, because the compressor has a lower flow rate than the exhaust stage does. If you build a jet engine using the rotors from a single turbocharger, you really end up with a turbo-augmented rocket. Which can still be entertaining (as it can make some thrust) but it has SUPER-shitty fuel efficiency.

If you could mate the compressor from a large turbo to the exhaust side of a small turbo, you'd see a lot better efficiency. But then you're back to the problem of machining nickel alloys.

,,,,,,,

I have seen it noted online that since there is less stress on the stators of a jet engine, then it might be easier to make the blades vertical and make the stators inclined instead. That is yet another project I'm likely to never get around to tho. :|
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>>914566
(continuing with blathering...)
The problem with trying to use turbos from junkyard cars is that the turbos are probably already ruined.

A turbo gets REALLY hot when the engine is running, and the turbo has to have oil circulated through the bearings for as long as it is hot.

When a car gets into an accident, the engine totally shuts off and loses all oil pressure. The oil left sitting in the [hot] turbo bearings "cokes"--it burns down into solid carbon, permanently locking/ruining the bearings. And disassembling the whole thing is way more difficult when the bearings are froze in place; you will usually have to hammer or press the pieces apart--and that usually bends the main shaft. So now the main shaft is bent and unbalanced, and you can't replace it separately (it is integral with the exhaust turbine).

As I've seen it you can't buy separate pieces for most turbos; you can only go to a car dealer or auto parts store and order a new or rebuilt turbo. So if you ruin any necessary part of the thing while disassembling it, the whole effort is a waste.

Also most (US) car salvage yards will remove known-good turbos and blowers off engines themselves, and send them to rebuilders for core fees. These are high-dollar parts (turbo = ~$750 or so) and nobody wants one that isn't good to use, so there's no point in leaving it on the car.... So even if you see a car in a US junkyard that had a turbo originally, it probably doesn't now.

The other problem is that the turbine rotors are very thin, and the steel used rusts very, very easily. Even if the yard leaves it on the engine--if any rain water pools in the intake, the blades are going to be ruined in just a couple weeks. The metal rusts quickly, and suffers deep pitting.

Car turbos are common, but kinda difficult to play with unless you know somebody who can get you a used one that is not already coked.
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>>914569

>when a car gets into an accident, the engine totally shuts off and looses all oil pressure

You mean the same way any regular Joe/Jane pulls up into a parking spot and turns it off with the shit similarly hot?

There are very few engines out there that have timers that run the engine after the user tries to turn it off. And that is to allow the turbo to slow down rather than cool down.
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>>914090
Depends. Something like your pic is gonna be pretty hard to pull off. I'd suggest you look into pulsejets and valveless pulsejets. They are quite simple in terms of design and can pack quite a punch if you make them big enough. Also there are TONS of plans online if you do a bit of digging.
>pic semi related and in German
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>>914090
yes, see my post >>914696
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>>914529
most are hastelloy, at least in turbochargers. none the less, you will get some power out of a cheap turbo made with a non superalloy, it will just collide with the turbine walls eventually.
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>>914721
>it will just collide with the turbine walls eventually.
No, not if you run it properly. This will only be an issue if you're careless and overtemp it. You have the exact same issue with even a high-end superalloy turbine, just at a higher temperature. Fancy alloys are no substitute for lousy engine regulation.
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>>914734
well, with a nice turbine, i know what the turbine material is. my shitty 150 dollar turbo from amazon, i have no idea. im gonna play it safe and keep the temps <1850f... but if you dont know the material, it is easy to overtemp.

my point being, you can get a shit turbo and drive it hard. yeah, eventually it will fail, but if it does, and you like the hobby, you can buy a better turbo. not a big deal fucking up a <200 dollar turbo
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>>914737
>my shitty 150 dollar turbo from amazon, i have no idea. im gonna play it safe and keep the temps <1850f
Well... if you truly have NO idea, the safest thing to do would be to keep it within the temps it was designed for (automotive EGTs, which normally shouldn't exceed 1,600f). If you have SOME idea of the material then obviously you have SOME further idea how hard you can push it.
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>>914758
if its low carbon steel, which would be the absolute shittyest, i could push it to 1800 and be safe. creep starts at 1900-2000f based on carbon percentage. structurally, i could probubly go over 2000 f, but dont plan on it.

i have all the temps and preasures measured on the combustion chamber, the compressor is the only unknown
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>>914770
Not sure where you're getting your numbers.
http://www.nationalboard.org/Index.aspx?pageID=181
>Carbon steel: 800*F
At 1800*F, steel won't just creep, it will actually yield and rupture at less than 5% of it's room-temperature strength.
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>>914721
>cheap non superalloy turbo
there is not a single turbocharger on the market made from any superalloy
>most are haynes/hastelloy
hastelloy is notable for its heat/corrosion resistance, literally never used for turbine blade material
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>>915001
>there is not a single turbocharger on the market made from any superalloy
...Yes, there is. Almost all of them are.
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>>914636

Usually when someone is pulling into a spot and parking they are idling the motor prior to shutting it down so the caking does not happen.
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>>915131

Often you find in accidents that the engines are usually at or near idle as well.

Automatic. Stomp on brakes but still hit at 30 mph you would find the engine was hardly turning over.

Manual.part of a serious emergency stop also calls for depressing the clutch.

If all it took was one 2,000-3,000 rpm shut down to kill a turbo then you'd have a lot of dead turbos.

I have seen women pull into spots accidentally pressing both pedals and shutting off the vehicle rather than adjusting their foot. Everything here is turbo diesel.
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>>915001
>there is not a single turbocharger on the market made from any superalloy
the wiki article for Hastelloy also calls it a "superalloy", tho I don't know right off what that term represents

>>most are haynes/hastelloy
>hastelloy is notable for its heat/corrosion resistance, literally never used for turbine blade material
inconel and hastelloy are both nickel-based alloys, and some types of the two are fairly similar (pic related)
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>>914090
chill out anakin, this isn't tatooine and there's no podraces here
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>>914315
You can use the compressor from a turbocharger or procharger.
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>>915176
maybe hes a sand nigger
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>>914667

I was going to suggest pulse jets too, but I'm not someone to ask.
Thread posts: 34
Thread images: 6


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