Introduction: Be an Aeronautical Scientist: Make Your Own Jet Engine for a Few Pennies.

Picture of Be an Aeronautical Scientist: Make Your Own Jet Engine for a Few Pennies.


You can make a real jet engine for five minute's work and the price of a spoonful of meths - how cool is that?!?

I doubt there's a better way to re-use all those jars under the sink. Much more fun than a trip to the bottle bank.

Step 1: Materials and Equipment.

Picture of Materials and Equipment.

Stuff I had lying around:

> Pasta sauce jar

> Matches or a BBQ lighter

> A hammer

> A screw (it should have been a nail, but what the heck).

> A tin tray

Stuff I had to buy (and the stuff that has caused the most confusion in readers):

> Meths

Step 2: Making It (the Lucky Way)

Picture of Making It (the Lucky Way)
OK, admission time - I got lucky with this Instructable.

Jam Jar Jets are by no means my idea, and I knew very little about them:

Knock a hole in the lid of a jar, splash some meths in the jar, give it a shake and light the meths.

So that's what I did, and it worked first time.

After running for a short time, with a noise like an angry moped, the temperature got too high for the jar and it gave way.

That was expected.





Then I tried to repeat the thing...

Step 3: What Goes Wrong...


"Daddy, show us how you made the jet engine!"

"Not a problem", thinks I.

I grabbed another jar, smacked a hole in the lid, splashed in some meths and lit it.

Foosh, then nothing. It didn't work. (There's not much point watching past the first few seconds of this video.)



After some research, it turned out that the hole was too big. If you make a jam jar jet, and it goes foosh and then does nothing, like it does in the first video above, then the hole in the lid is too big. Go make another one.

(Later)

If your jet lights, goes foosh, and then goes RRRR for a moment, like it does in the second video, then your hole is not quite big enough.



Step 4: Getting It Right.

Picture of Getting It Right.

People that do this properly use proper tools, but it is possible to get it right with just a hammer and an inappropriate spiky thing.

If your fuel is meths (recommended), and you're using a pasta sauce jar, then the hole needs to be about 10-12mm across.

When I prepared a new jet, with a roughly circular hole about 10mm across, it nearly worked. It lit, went foosh and then RRR for a second.

A couple of minutes prodding at the edges of the hole with a screwdriver made the hole about 11mm across, and it ran well. Really well.

But I forgot to video it!

Never mind, I put the flame out and let the jar cool for a few minutes, then tried again. Yipee! It worked!



Step 5: How to Do It Properly...

Drill a nice, circular hole in the lid of your jar.

Splash a few millilitres of meths into the bottom of the jar and screw the lid on tightly.

Put your thumb over the hole and shake. This coats the jar with fuel and adds vapour to the air to aid ignition. If everything is going well, the jar will make a sort of sucking noise when you take your thumb off the hole.

Stand the jar of a heat-proof surface (it will get really hot), wipe spilled meths off the top and light it.

If the jet works, and you want to use it more than once, don't let it run too long. Extinguish it by dropping a spare lid over the hole of the jet - let it cool before you pick it up!

If you get one running, add a video to the comments. One day, in the distant future, I'll make one out of metal and add a fuel-feed. I wonder how loud it will be...

Comments

ecogeeco (author)2017-02-05

Thanks for the Ible. We had a lot of trial and error but we got ours to start. Still going to try going further with it.
https://youtu.be/5kTQX0uv3Pg

Bebo1021 (author)2016-05-17

Would it work if I used an empty paint can?

dmagee725 (author)Bebo10212016-06-01

if you weld the lid on

Kiteman (author)Bebo10212016-05-17

It's definitely worth a try, but be very careful not to lean over the can as you light it, just in case the lid comes off at speed:

fahadshihab (author)2015-09-17

Really cool build, Kiteman...

Will it be a good idea to build one from deodorant cans with continuous fuel supply...? I have plans to build one XD

d_dmob (author)2014-03-21

Nice work.....

I would like to ask how many minutes does it take for the flight and how much distance covered with the fuel full?

Kiteman (author)d_dmob2014-03-21

I'm afraid that this doesn't actually fly, it lacks the thrust.

Running time varies, but is usually around a minute.

d_dmob (author)Kiteman2014-03-22

Thanks!!!

andrea biffi (author)2014-02-11

Do you think it will work with a bottle too? It could be an easy way to break the bottle after engraving a groove to make a glass, but it probably smashes...

Kiteman (author)andrea biffi2014-02-11

It depends on the bottle - if it has a short neck, it might.

Give it a try - the worst that could happen is that you make an alcohol lantern.

andrea biffi (author)Kiteman2014-02-11

All right, I'll let you know :-)

manoo (author)2013-09-04

is alcohal fine

Kiteman (author)manoo2013-09-04

Whiskey, rum, vodka, pure alcohol should all work.

Beer, cider, they do not contain enough alcohol to burn.

manoo (author)Kiteman2013-09-04

how to make it

Kiteman (author)manoo2013-09-04

The alcohol? Ferment some, then distil it.

The jet? Scroll up...

manoo (author)Kiteman2013-09-04

how to make it

manoo (author)2013-09-04

how to make it

manoo (author)2013-09-04

how to make it

tobychan (author)2012-11-23

I drilled a hole in the cap of a 500ml Lucozade bottle around 8mm hole diameter. Then put in enough meths so that when you give it a shake, it just about coveres the inside of the bottle. I laid it on its side, put a flame to the hole and it went blasting off about 10 meters!
These engines were used in the V1 and V2 rockets by Germany. They would calculate fuel consumption and put exactly enough fuel in so that it ran out over London and the warhead would plummet down.

lancealotx21 (author)2012-10-24

So what exactly is a Meth?

Kiteman (author)lancealotx212012-10-24

<em>Meths</em> is actually methylated spirits - please read the rest of the comments.

Kiteman (author)lancealotx212012-10-24

<em>Meths</em> is actually methylated spirits - please read the rest of the comments.

Mythbuster Kid (author)2012-07-30

Could you use rubbing alcohol?

Kiteman (author)Mythbuster Kid2012-07-31

If it's flammable, then yes.

Mythbuster Kid (author)Kiteman2012-07-31

Thanks.

IronWill (author)2012-06-13

pretty cool, but I'm concerned about the potential glass shards being scattered IF it was to explode.
perhaps use a tin can or at least tape the glass container. so that it may break but not harm anyone.

nice guide though.

Kiteman (author)IronWill2012-06-13

They don't explode - the big hole in the top means they can't build up enough pressure to do that.

The reason they break is because the temperature differences across the thickness and height of the glass causes fatal fractures.

IronWill (author)Kiteman2012-06-15

still not worth the risk too much meth is being used.
i am not saying your project is flawed, I'm giving a heads up to those new to it.

Tim Temple (author)IronWill2012-07-02

If you want safety, rub the bottom of the jar on the sidewalk and suspend the whole thing from a cord. That way the bottom will blow off without causing any frags.

Kiteman (author)IronWill2012-06-16

Hey, it's cool.

Everybody should assess their own risks, and if my project is too much for you, I'm not insulted.

boom man56 (author)2012-05-27

where did you git the Meths?

Kiteman (author)boom man562012-05-27

You'd need to ask your parents to buy it. See other comments for suppliers.

The Dark Lord (author)2012-02-19

Have you tryed using this to propel a model rocket? ( Or other mode of transport?)

Kiteman (author)The Dark Lord2012-02-19

No - the burn cycle it very sensitive to symmetry, and tends to stop when you lay the jar on its side.

I do keep meaning to try adding an absorbent pad to hold fuel at the bottom of the jar to see if it works in its side then, so maybe you'd like to experiment for me?

BrianRandleas (author)Kiteman2012-05-07

I suspect that it is the air fuel mix that is killing it when you lay it on it's side. Try putting your hole near the top of the jar instead of the center and see if that works for you.

Kiteman (author)BrianRandleas2012-05-07

According to what I've read*, the burn needs to be symmetrical to be successful.



(* Which isn't much)

andy55551 (author)2010-11-20

is there a way so it doesn't brake at the end?

skatattookid (author)andy555512012-02-21

i keep mine water cooled and also wrapped the glass in duct tape so if it does break its easy to clean up without getting cut. you can also just drill a hole in a can of broth and just use that.

That was my thought on using a metal can as well. A beer can or soda can pierced from the bottom instead of "Popping the top" should work as well. If you can find a way to pull the bottom into a cone shape that should also give better results if your wanting even negligible thrust. If you are using a metal canister you should also be able to lay it on it's side. More important than the shape of the flame is the air to fuel mixture you are obtaining.

Kiteman (author)andy555512010-11-20

Some people recommend standing the jar in cold water, but I would like, one day, to make a metal version, maybe with water flowing round heat-transfer pipes...

Aldeas (author)Kiteman2011-08-14

Have you looked up the heller/lockwood version of the valveless pulsejet? That version uses a u shaped arrangement of the tube with and expanded combustion chamber to set up the harmaonic combustion pulse. one guy ran a gocart on one of these things using propane as a fuel.

BitBoink (author)Aldeas2011-12-24

Ya I remember SRL (Survival Research Laboratories) did a pulse cart back in the 90's. The pipe was glowing bright orange-hot right behind his head if I my memory serves well ... was insane looking!

orangetj (author)Kiteman2011-10-22

or possibly have a undamaged lid freeze the jar with the meths inside and then swap lids? but then again it might get hot fast and break sooner

ELITE-01 (author)Kiteman2011-09-12

I haven't tried this specifically,
but just as a reference to something I have done, unintentionally,
Rap a jar containing a candle in a cold, wet rag. The glass breaks pretty quickly, large cracks, some shattering, the works. so i'd assume that cold liquids, of any kind, with hot glass is a no go. 

youkneephsycle (author)2008-03-08

about to go try this with a beer can replacing the jar, thet way it cant smash and the hole is a pretty good size anyway.

Here is an idea. Instead of "Popping the top" on the beer can, sacrifice one by popping a small hole in the bottom of the can instead. If you don't want to waste the beer use a soda can instead.

Kiteman (author)youkneephsycle2008-03-09

Oh! Let us know if it works, plus all the details - brand of beer, ~~flavour and alcohol content,~~ dimensions of can, dimensions of the hole, type and volume of fuel... ... and how about a video as well?

Zaphod Beetlebrox (author)2012-04-27

I wonder if it work with a pop can. Or would the hole be to big.

I tried once, it just went woosh.

Kiteman (author)Kiteman2012-04-28

Although, you can get taller, narrower cans these days...

If you try it, let me know what happens.

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