OK so I tricked you into taking a look at a "computerized" Stirling engine. Actually  some of the engine is made from several computer parts recycled from a couple computers. The intent was to use as many "computer" parts as possible. More so than that,  I really was trying out a few new techniques that I though might work and would be easier to accomplish by beginners. Plus I was trying out a few new ideas for the horizontal tin can stirling under construction. I will discuss these new technique under each photo below. As for how the engine ran well.................It suffered catastrophic failure after about 50 revolutions. It ran good when it did run but one of the new techniques I used  failed. The displacer piston separated from the rod that controls it.  It then came to an abrupt stop.  (more below) However many new techniques that were used worked quite well, just not all of them!

This is not intended as "PLANS" to build this engine.


                          

On the left, the displacer cylinder. The top was made from the heat sink from a computer CPU. That is the piece that cools down the main computer chip in a computer. (more details later) Also around the side is another heat sink form another computer. On the Right, the fly wheel. Made from a CD disk (compact disk). The main bearings on the flywheel are from a CD player along with the hub.

This is a detail photo drilling out a small brass "stand off" that supports the main "mother board"  in an old computer. This piece will become the brass rod guide on the top of the displacer cylinder.

                             

These photos are how I squared that brass rod guide to the top of the displacer cylinder. I took an old heat sink (as stated above) and drilled through the middle of it with a hole saw. That made it close to the size of the can I chose for the displacer cylinder. I then sanded it to fit tight in the top of the displacer can. I drilled a hole in a wood board the size of the rod I was using and pushed a piece of the rod in it (see photo on left) I lowered the brass guide down the rod. Then I dropped the heat sink over it. Here is where I went wrong. Although this is not the piece that failed in the end, it is the same technique used that failed. I used CA glue (medium set super glue) to attach this guide to the heat sink.

I have build several steam engines and they call for using this glue to hold on some of the parts. I wanted to see if this might be a good alternative to soldering as on my "bigger" stirlings. It is a "medium" set CA glue. In other words, it doesn't setup fast like normal super glue until you hit it with an activator. Then it sets. This gives more time for installation. (more later) This technique worked very well on the top of the engine, but I would not use it down lower to the "hot" side of the engine as you will see later why.

This is the displacer cylinder. It was a WD40 small spray can. Instead of trying to solder on a power piston cylinder I decided to try to "bolt" it on some how. I selected  (from left to right in photo) WD40 can, 1/4" brass bushing, 3/8" to 1/4" brass bell reducer, a short piece of 3/8" brass pipe nipple (i cut of the threads on one end). I ran a 1/2" drill bit on a drill press (you could use a hand drill) to ream out the inside to 1/2" for the piston.

I assembled these item and used high temp silicone around all the joints. This silicone can be bought at any automotive store. This technique can be used on the larger tin can engines also as it worked very well and the silicone never had a problem with the heat. Two techniques that worked well so far.

Photo of what it looked like inside the displacer cylinder before adding the displacer.

The displacer: Made from butane canister that is used to refill butane lighters etc. Cut down and the top portion "glued" onto the bottom using the Hi temp silicone. This worked well also and was not the problem (not yet!).

I drilled out the top and the bottom of the butane canister and inserted the rod all the way through it. I then used CA (super glue) to hold it onto the rod. This is the joint (and the one below) that let loose when the engine got too hot. The CA glue could not take that much heat.

This is the bottom of the the displacer where I also used the CA glue that failed. It turned out to be catastrophic because when it failed, the displacer fell of the end  of the rod inside the sealed displacer cylinder.

Here is the entire unit mounted onto the engine. The top heat sink was glued on using CA glue. Again this worked out OK. Notice I used copper pipe clamps to hold the displacer/power cylinder on. This is another new technique that worked great.

The Power Piston: Made from a 1/2" diam. capacitor taken from the power supply of the computer. It was gutted and the end cut off  to form the piston. A small piece of brass flat stock was bent in a small "L" shaped and a small hole drilled in one end. The other end was inserted into the piston and it was filled up with JB Weld. This was a new technique to me and worked out quite well. On the end of the rod was a small radio controlled airplane rod end for swivel.

Drawing of capacitor





Preparation of capacitor to make piston

Close up of the mounting of displacer/power cylinder.

On the top of the displacer cylinder was another heat sink cut into small sections and CA glued to the side of the displacer cylinder. The were also wired on. This is a technique I wanted to try and use on the horizontal tin can engine coming next. It proved to work out quite well and solved a big problem (cooling) of the horizontal tin can engine.

Close up of the walking beam.Taken from a support rail of a larger main frame computer and re machined. All the bearings and joints on the rod were radio controlled airplane rod ends from the local hobby store.

Another look at the flywheel. Made from a CD disk (compact disk). The main bearings on the flywheel are from a CD player along with the hub.

The completed engine just before it's second  (and last) attempt to start it. After making some adjustments from the first attempt (would only run a few revolutions then stop) a second attempt was made. I stoked up the sterno (maybe too much!) and fired it up. It started to run quite well and I was enjoying it when after maybe 50 revolution it came to a crashing stop. The rod going down into the displacer had separated from the displacer inside the displacer cylinder. Not much chance of repair as the top of the displacer cylinder (top heat sink) was CA glued on and not removable. The engine was finished but...... Parts such as the bearings (rod ends) and side heat sinks etc. are being reused to finish the horizontal tin can stirling engine. I hope the horizontal engine works out better!! Well.....Back to the drawing board!!

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