Tin can pulsejet

[Tony]

OK so I've had a go at making a Methanol/IPA powered tin can pulsejet, starting with the 10mm aperture recommend on a youtube video.

First off, I wish I had a soup can.  Getting all the bits of chopped tomato through a 10mm hole left the kitchen looking like a murder scene.

As it turns out, it's very easy to make a tin can that goes "WHEEEEP" when lit, spitting out a little blue tongue of flame then going out.

I've tried all sorts, pinholes in the sides to let some oxygen in, increasing the hole size (not using an electric drill since it was full of flammable vapours) and even arrangements with copper pipe chimneys.

The only one that worked cyclically had the copper extend down into the can itself.

It would light, burn with a gentle flame then go "WHHHHHOOOOP" firing an utterly terrifying column of fire into the sky, return briefly to a gentle flame then repeat, but more violently.

At that point I chickened out and threw a bucket of water over it.

Shame, I'd love to make a working one for the BBB (rather than a device that will make people run a mile!)

[kamaangir]

You can't not bring it after that description!

Have you worked on a guidance system for it yet? 

[julesandtash]

It wont make us run a mile.
We are the bunch that were crowded round a babbington burner with a piece of steel tube glowing orange whilst supported on just a couple of empty beer cans.

If it gets too terrifying, we'll just push the womble to the front.

[Rotary-Motion]

yes bring to the BBB and get womble to hold it

be good to see it tony...

[julianf]

It would light, burn with a gentle flame then go "WHHHHHOOOOP" firing an utterly terrifying column of fire into the sky, return briefly to a gentle flame then repeat, but more violently.

At that point I chickened out and threw a bucket of water over it.

Surely a man of your tallents could manage a youtube upload!

[Tony]

I'll re-light it tonight just to prove it still works/doesn't explode.

I think what is happening is that the copper chimney allows it to keep a pilot light going until the air holes around the base allow the mix inside to reach an explosive level, which then jets out of the pipe taking some additional Methanol liquid with it due to the force of the expansion - which gives the column of fire.  Then it returns to the pilot light stage.

[Head Womble]

It's sounds like great fun, you must bring it along.

It wont burn my furr will it ?

[Tony]

I'll bring it along though we'll probably need a bucket of water on standby!

[Glycer-rides]

If it's the first you've made, you should call it the V.1
Perhaps Jim could put wings on it?

[nigelb]

If it's the first you've made, you should call it the V.1
Perhaps Jim could put wings on it?

....or the V.A4..................you had to be there!!!!!!!!!!!

[julesandtash]

Can we have one like this at the BBB please Tony?  All that white hot steel would like great at night

http://www.youtube.com/watch?v=EEHw9lInIfg

[K.H]

If it's the first you've made, you should call it the V.1
Perhaps Jim could put wings on it?

....or the V.A4..................you had to be there!!!!!!!!!!!

Don't start getting ideas for next year!

[Tony]

Surely a man of your tallents could manage a youtube upload!

I'm all over it.  This evening it wasn't re-igniting - maybe it has to get nice and hot to do that.

http://www.youtube.com/watch?v=b-8qokyiiCI

(Might take a while for youtube to finish cropping and rotating it but you get the idea)

[Tony]

I've made one that motors nicely now I'll bring 'em both to the BBB.

[nigelb]

If it's the first you've made, you should call it the V.1
Perhaps Jim could put wings on it?

....or the V.A4..................you had to be there!!!!!!!!!!!

Don't start getting ideas for next year!

You're gonna have to build something. This could be just the thing