Ancient Aeolipile -steam Engine, and Magnets for Good Measure...




About: Engineer making renewable energy products for African entrepreneurs.

The first steam engine was invented by Herron of Alexandria around 150BC (actual date is unknown -- that whole Alexandrian library arson thing :/ and books disagree on dates). The history channel (or was it discovery) called this person Mechanos - I'm not sure where that name came from, but it fits :P

So basically, it is a sealed pressure vessel with steam outlets. Hot steam is pumped in (or generated within) and the steam outlets provide a torque based on their perpendicular component to the radius of rotation. You also need some sort of bearing to allow for rotation ;)

Well, pressure vessel could be a fancy name for soda can....

You'll need:
1 Un-opened soda (or other) can
A few feet of fishing line or other thing string
Awl or other hole punching device
4 tea lights
Two magnets and two ball bearings :P

Videos on steps 1 and 3 ;)

Step 1: Prepping the Can

Using an awl or other suitable tool -- puncture a small hole about an inch from the top of the can. Be sure to do this in your bathtub/show/sink as it will spray out soda. Then have fun and shake it up to get as much out as possible (or suck the soda out).

Next twist the top tab around and bend it upwards. Remember the goal is to make a sealed pressure vessel with one outlet for steam. If you break the seal, you'll need a new can and you'll need to start over.

Now (as I discovered in my second attempt), only puncture one hole -- and then slightly dent the can so that the hole points to one side.

Step 2: Suspend Your Can; Making a Bearing.

Well, to make this work well, you need some sort of bearing (to allow continuous motion). To do this, I epoxied a length of fishing line to one of my little magnets. I then attached this magnet to a steel ball and tied the other end to the upwards-bent soda can tab.

Using my magnetic toy choking hazards, I constructed a little string hanging from the vent above my stove. At the bottom of this string, I placed a ball.

I then attached the two balls together -- this creates a bearing of sorts

Step 3: Filling and Starting

Somehow, put about an ounce or so of water into your can. I used the syringe I have for measuring nutrients for my hydroponic garden... The exact amount is not as important - you just don't want to overfill.

Now hang your can filled with water and place 4 tea lights underneath. You want very little space between the flame and can. Light up and let it sit. It took about 5 minutes to start steaming and a little longer to build enough pressure.

With the help of my lighter (or two), I got it started much faster. The next time I do this (for fun :P), I'll have to count how many RPMs I was reaching...



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    54 Discussions


    2 years ago

    Instead of having to punch holes on the side of the can, we could try to drill two holes perpendicular to each other on the curved surface and then stick flexible straws in them, with both straws pointing clockwise (or anticlockwise) and then make the joints air tight with hot glue. This way you wouldn't have to worry about 'denting' the side.


    3 years ago

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    6 years ago on Introduction

    i have built this and have found that if you take some fine copper piping and stick it int the hole it gives more concentration in the direction of thrust if that make sense :)


    11 years ago on Introduction

    To make filling easy for ppl who don't have a syringe (my family is weird. every time we get one of those things it disappears into my little brothers room....), I would pop the top and fill it through there, then seal it in some temporary way. duck tape maybe? I think that would be easier. Good instructable, gotta try it out some time.

    2 replies

    10 years ago on Introduction

    Butt Rub -- excellent stuff for rubbing on your butt (why do butchers call the shoulder the butt?)

    because nobody would eat something called butt if it was actually butt. hence rump roast not butt roast...


    11 years ago on Introduction

    I want to try making one of these using this kind of can. It has a screw top so emptying and re-filling it are easy.


    11 years ago on Introduction

    he he he... put some blades on that and youve got an evil death machine... MWUA HA HA!


    11 years ago on Step 3

    I've seen a lot of these over the years. I made mine, about half a century ago, from a brake fluid can and a rubber stopper. the string was attached to a pin through the stopper, and the bearing was a fishing-tackle swivel. I never would have thought of your magnetic bearing, even if we'd had neodymium ball magnets in those days. Note that the original had the rotor separate from the boiler. I wonder how Heron did the steam-tight rotating joints. I suspect that he just let them leak more steam than went through the nozzles; the thing looks more like a proof-of-concept model than a practical machine.


    11 years ago on Step 2

    The magnet bearing is almost friction-free! I don't have those parts so I'm going to try using fishing swivels or a beaded chain for my first attempt.


    I like your style. Great instructable. I think I saw that history channel thing, too. The guy who invented this made all KINDS of cool stuff. He had a lot of gravity-powered entertainment devices, like automated puppet shows. Amazing. I think I may build one of these things.