Be an Aeronautical Scientist: Make your Own Jet Engine for a few Pennies.

Step 2 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...

Comments

[youkneephsycle]

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.

[BrianRandleas]

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]

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?

[thomasready]

Your crazy I hope my grandkids don't see this killer hand remover

[The Dark Lord]

Maybe teach your grandkids basic safety...

[Kiteman]

"Killer hand remover"?

>rolls eyes<

[smpash]

interesting but wouldn't it be better to use a metal pipe instead of a jar just weld or solder a washer over one end and a plate over the other

[Kiteman]

It would, if I had welding equipment, and if the engine didn't get hot enough to melt ordinary solder.

[danialmcghie]

so the next step if you want to create thrust is to establish a way that the neutral force created outside of the whole perhaps turns a small fan to push the thing, if its in water? mbe attach small metal rotors (just spitballing) just outside the whole

[Kiteman]

I haven't tried it, but it is my feeling that the most promising way to generate thrust from something like this is indirectly - use the heat to boil water, then utilise the steam pressure.

[Electorials]

"Then I tried to repeat the thing..."
haha!

Nice instructable Kiteman ;)

[pandadude]

I've done something like this before, but instead of a jar, I used a water jug used in a water cooler like at an office, and when shaken and lit, it made a very loud wooosh.

[Tmbo17932]

would it be safer to put the jar in a bucket of water or something?

[Kiteman]

You could try - the cooling effect might make it last longer - but be careful it doesn't float away.

[Lance Mt.]

Try it, Then video it. see how much thrust it has.

[Kiteman]

Running this on sclaes shows; almost none.

[Lance Mt.]

 Hmmm. What can we do to fix that? I'm thinking multiplying jars.

[LiquidLightning]

Won't work no matter how many jars, the one hole acts as both air inlet and jet exhaust, creating positive and negative thrust, which cancel each other out.

[girrrrrrr2]

ok my lid flew off and went over 30 feet away...no wind...what did i do wrong...i used heet...and used a self sealing mason jar...amd i has a 3mm hole in the lid... and then i put back on the lid and it still fits...

[jer20084]

lol same thing happened to me i was using rc racing gas as fuel and a glass starbucks mocha container and it lit a few times and and burnt for 2 seconds and then went out and on the third try the cap exploded off and burning race gas went all over me. :(

[girrrrrrr2]

light it!!! lol... dont...

[Kiteman]

You made a bomb! The hole needs to be a lot bigger (10-12mm) to allow the pressure to escape as a jet and then let fresh air back in. You must have conincidentally had a perfect air/vapour mix when you lit it, and the whole thing exploded. Is the lid screw-fit or push-fit? If it's screw-fit, you are very lucky that the thread gave way instead of the glass. Maybe the heat made it expand so that the threading was too large for the jar. If it's push-fit, then it will fly off every time, no matter what size your hole is. Keep trying.

[girrrrrrr2]

its weidrd the thread is still functunal and the lid is a ring with a plate in the middle...it screws on... i kept trying...but i only have one lid and i made the hole too big now!!!

[Kiteman]

Try fixing a washer over the hole ("No More Nails", JB Weld? I'm trying something called "Serious Glue")

[xegghead15]

so if the hole is bigger it wont explode??

[Kiteman]

That's the idea. There has to be space for the flame + pressure to leave and then suck in more air.

[skaternate111]

u could probably put a tin can in the jar and put the meths in that