Stirlingengineforum.com

Hello there,

An aircooled tincan stirling gramophone, that's what I want to make. There is only a little problem: I 'discovered' the 'magic' from stirling-engines only one week ago. In the meantime I've been reading into it, trying to understand how it works (which is pretty clear so far).

On youtube I saw them homemade tincan stirling engines running ( http://nl.youtube.com/watch?v=I7Jy7SIKikc would a design like this work when you put it horizontaly?). I'm sure that I can make one of them vertical standing ones. I found some plans on internet. But to create a gramophone I'll need to build a horizontal one. Does anyone know if this is as 'simple' as building a vertical one, or will I have to build it very different.

Another thing is that I want it to be (and look) as simple as possible. So aircooled (not watercooled) and nothing more than the parts needed to operate the engine.

Actually it has to look like 'junk', as if it's impossible to work. Someone watching it has to be surprised to see it running (and playing music ;-)

Any ideas, suggestions?

Sincerely,

Charlie

Hi Charlie,

I've built this particular engine and it ran the first time I fired it up. There are a couple of things to consider if you wanted to turn it on its side. First, it is designed to have the heat source below the displacer cylinder. It might still run if the heat came from the side of the can, but I suspect it would heat more of the cylinder than we would want, making it less efficient. Second, the displacer inside the cylinder drops straight down; it is suspended from a wire directly above it. If this were turned on its side, the displacer inside the cylinder would no longer remain centered. This would cause it to rub against the outside wall. More importantly, we would lose the advantage gravity provides in pulling the cylinder down during half the cycle. In short, while this is a great demonstration engine, it is not suitable for your purposes if it must be turned sideways.

You will find that many of the handmade hot air engines have a vertical displacer cylinder because it simplifies alignment of the displacer within it. I'd suggest considering a means of transfering the engine's motion to your phonograph with either a belt or gear, particularly since you will probably need to adjust your rpms to an appropriate speed.

Good luck on your project!

-Stefan

Hi Stefan,

Thanks for your reaction. That makes sence. I found a description of a horizontal one on Boyd's website ( www.boydhouse.com/stirling/horizontal/index.html ). But at this moment it looks to complicated to start with. So I think I'm going to try your idea with a vertical engine and transfer the rotation with a belt or gear.

I'm going to work on it in three steps: First I'll try to build the vertical engine. Second I'll try to figure out what would be the best way to transfer the vertical rotation to horizontal. Third: figure out the gramophonepart. Especcialy the rpm will be fun I guess: Will it sound like dark demons or like the chipmunks?

By the way, with the gramophone part I'm also going to try to make the horn and needle from wastematerials. Curieus if that's going to work.

Anyways, a very interesting project for someone who hardly knows anything about how to realize it. But that's the challenge.

Cheers,

Charlie

I've actually used a paper cone and a sewing needle on a turntable and could hear the recording. Not exactly good for the record, but it sure was fun!

-Stefan

Cool!!! That's what I was thinking about. I've seen it once in a movie called 'Gadjo dilo' from Tony Gadlif. Here a guy also makes a gramophone from junk and uses an old newspaper and a needle.

I 'made' my first stirling by the way. Ordered an assembly kit for $ 20,- on Ebay ( www.astromedia.de ). It is a 'coffeecup-stirling' made from cardboard, plastic, etc. And it works! Amazing.

Time for my 'own' design.

Cheers

Hi Charlie,

Stefan is right about trying to keep the displacer vertical. The Horizontal tin can engine is border line a failure. I have done everything I could to just keep it running. Even at that I can't keep it going longer than a minute and a half. Trying to get it to do "work" is not an option at this point. I'm sure there are a few thing more I could do I have over looked, but I don't think it will ever get much further. Not without some machining and better materials. That was the point of that engine, to be made from common items, but common materials can only go so far.

Darryl Boyd

Hi Darryl,

Thank you for sharing that information. And thank you for your inspiring website! It makes my fingers itch to start building. I figured out how I'm going to (try to) build the gramophone with a vertical engine, so time to collect the material I need.

Sincerely,

Charlie

Here's an E-mail I recently wrote:

"Dear sir, I am very pleased to find your very interesting site. I believe I may have some answers about your Gramophone for your consideration, which I think is a "Gamma".

http://www.dself.dsl.pipex.com/MUSEUM/C ... ophone.htm

If it was an "Alpha", the two cylinders would each have power pistons, one cylinder being cold, and the other hot. Their cycling must be 90 degrees out of phase, but if the crankshaft has two throws (instead of the less expensive single throw) the two cylinders can be arranged at any angle in relation to each other (much like the two hands of an old clock) including inline, such as this engine.

The "Beta" style has both displacer and power-piston in a tandem alignment in one cylinder. Due to the difficulty of lubricating the power piston sealing rings in a hot environment (and also the rod seal), the power piston and cold end are typically located near the crank shaft with the displacer on the hot end.

I am certain your gramophone has a Gamma Stirling engine, if you will allow me to present my case...

A Gamma is very much like a Beta in function, but the power piston and the displacer "heat transfer shuttle" piston are in separate cylinders. In the third picture, the discolored metal cylinder end is the hot end, under which would be placed the burning "Sterno" cup (gellied alcohol). The displacer (a sealed hollow loose piston) fills half the volume of the heat transfer cylinder. Its movement back and forth would force air to occupy the hotter end (raising pressure) or then the cooler end (lowering pressure).

The white sleeve would be an insulating cover, and combined with the black cone (heat outlet exhaust), they would both prevent the exhaust heat from damaging the high-quality wood.

In the second picture, the sheet-metal box on the left captures the rising heat and enshrouds it around the heat exchange cylinder. The lower horizontal cycling rod clearly is moved by a crank arm on the right that is in the fully retracted position. By doubling the arm length we see the length of the displacer stroke.

When the displacer is extended, the air is forced to the cooler end. It is difficult to see, but it appears there are 4 vertical cooling fins obscured by the central mounting brace inline with the displacer (3 are visible).

Air that is either heated or cooled is drawn off from the middle of the displacer cylinder, and it rises through a hollow flat plate and then turns to the right through a thin tube that has the 5 prominent cooling fins.
``
Since the crankshaft is vertical, and the power piston must be attached to the other end (top), we now realize that the power piston is at the base of the 5 cooling fins (on the right side of the fins), and the crank arm for it is just below the red arrow.

The heavy horizontal disc inbetween the two crank arms is a flywheel, and due to the location of the sheet-metal cover over the power cylinder, I suspect the flywheel also acts as a fan. The flywheel appears to have an opening under it by the crank attachment, and the upper side of the flywheel has holes near the edge. If it is hollow as it appears to be, air would flow up from the cooler bottom through the center, and would be flung outwards to the edge by centrepidal force, exiting upwards through the edge holes.

I am working on a solar-heated Gamma Stirling engine, and I recognized that this engine is very similar to the one I have designed ! I am pleased to see this configuration was already working in 1915 (93 years before mine!) just as electricity was taking over. I would be very interested to see exactly how the speed governor on this engine worked. Apparently there is no need for me to re-invent the wheel !"