Ugly Duckling Update

[theropod]

Hey All,

I finally got my larger power piston/cylinder combo from Airpot, and man what a difference! I've also added a water tank to the top and that really seems to help lengthen run time and responsiveness.

The engine now will turn at what I think is around 180 to 200 rpm with a good flame from the propane torch. More impressive is that with a candle set "just so" from the bottom it will run, not at a very high rpm but turns over! I'm trying ice in the water on my next run test.

I've also wrapped the hot end with fiberglass up to the power cylinder and this seems to enhance run time as well.

I JB Welded the glass cylinder to the side of the displacer after giving both a good scrubbing with alcohol.

The plain piston/cylinder setup presents a small challenge. The undersized sample snubber had a ball joint for the connecting rod, and this only had a tiny hole passing through the face for a screw in the piston. I had a sight pin mount (brass) for archery and found a screw that fit the threads. The brass sight mount, a tube with threads, was soldered to a small bearing directly on the skirt side. I used a 90° bend in a hunk of 1/8" brazing rod as a wrist pin, and solderd the long end to another segment of the connecting rod already attached to the crank for the right throw length. The piston screw hole was countersunk and after cooling was assembled to the sight collar/bearing/connecting rod.

I ordered a 3.5" long setup, and this leaves about 1.5" of dead space between the face of the piston and the displacer. I am seriously thinking of packing that space with crumpled fine copper wire for a regenerator. I have several old microwave transformers and the high side has a pile of such thin wire. I think burning the enamel insulation off and then etching the copper wire. Thnk that'd help with heat handling between stokes and maybe gain a little efficiency?

So, that's my update and a link to pictures of the new power piston/cylinder will be provided soon.

Roger,

[theropod]

Hi All,

As promised here are links to pictures of a few details on my engine.

http://gobblerguns.com/roger/images/displacer_lift.jpg

This is the way I devised to lift the displacer rod. Made from 1/8" brazing rod and to be replaced with a smoother setup soon. However this setup allows for operation of the displacer without having to be dead center under the lift point on the walking beam. The VCR bearing/shaft allows for in/out adjustment and the loop/hook allows for forward/back adjustment.

http://gobblerguns.com/roger/images/dis ... dgland.jpg

This is the part I built from the guides on a CD player tray that guides the ejection of the disk and a hunk of 3/8 copper tube. These are made from some hard steel and chrome plated. Very smooth!

http://gobblerguns.com/roger/images/pistonsideview.jpg

This is the new Aipot glass power cylinder and piston showing the method I used to make up the wrist pin. I may shorten this from the current bearing point toward the displacer side of the piston. There is a very slight drag as the piston reaches full depth of travel. I don't know if the con rod will contact the end of the glass tube at that point, but I'll see.

I'm looking to make this ugly duckling into a sweet little engine when all the bugs are worked out, and so far it becomes a better engine with every modification.

Suggestions, advice and comments are welcome and invited.

Roger,

[Cartech]

I love the pictures, what does the whole thing look like?

[Cartech]

Oh, my bad. I've seen the whole engine pictures in another thread already, sawblade flywheel right?