Latest project complete

[Evan]

I made myself a toy over Christmas, finished it this weekend.





It is of course a steam engine. It is designed to run on extremely low pressure. All the rotating bearings are ball bearings. The piston is silicon bronze running in an aluminum cylinder. The valve system is balanced so that the valve does not work against air pressure. It runs either direction by moving the air hose from one nipple to the other. It is a very long stroke engine to maximize the use of low pressure. Stroke 1", bore 1/2". The connecting rod is very long to minimize side force on the piston thereby reducing friction.

In the photo above it is running around 200 rpm on 0.6 psi. I measured the running air pressure from the aquarium pump with a highly accurate medical mercury manometer, accurate to 1 mm pressure over a range of zero to 300mm.

This is the first engine I have built, I think it won't be the last.

[G.A. Ewen]

Thats a dandy Evan, but I think I see some finger prints on it in the first photo .

Really, it is a beauty! Is it your own design? I have never seen one like it.

[Evan]

It is my design but is loosely based on some other designs that use the bellcrank to transfer valve motion from the eccentric to the valve body. BTW, before anyone asks, there are no plans...

[Thrud]

Nice.

Needs some anodizing...

[Evan]

Yeah Dave,

When it warms up I will sand blast the base and anodize it. I haven't decided on what color yet.

[winchman]

Very nice work.

Which part was it that got scrapped? Or was that a different project?

Roger

[spkrman15]

Yeah i want to know which part got scrapped. Very nice. Don't Anodise it. It looks great the way it is.

Spkrman15

[pgmrdan]

Don't change a thing! It's beautiful just the way it is.

Very nice!

-Dan

[NAMPeters]

Nice and shiny, I like it. First rev would be a shuttle valve for direction control, moving a tube is too mickey mouse for such a neat engine.

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Neil Peters

[Paul Gauthier]

Very nice Evan.



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Paul G.

[Al Messer]

Good job!!

[Evan]

It was the valve body that holds the cylinder that I screwed up, twice. The first time I drilled the holes for the bolts that hold the cylinder a few thou too close to the hole for the valve rod. I was using a three bolt pattern and that is where they fell. It looked clear but wasn't. I switched to a two bolt pattern. The second time I made the hole for the valve rod a few thou too large. Third one works.

The valve rod is hard anodised aluminum running in aluminum. Man, is that hard anodizing ever hard. It actually sparks if you grind it. I had to use a diamond insert to turn down the valve rod for the valve port reliefs.

[This message has been edited by Evan (edited 01-13-2004).]

[Al Flipo]

Evan.
To say that I am impressed with your ability and enthusiasm would be an understatement, I personally suffer from the opposite.
The wife and I owned a commercial machine shop for over 20 years, and a couple of years ago we decided to retire at a fairly early age (just over 50).
We did set up a complete hobby machine shop in our present home, but I just can’t seem to get motivated to get in there and actually do something.
I make and install the occasional muzzle brakes, and a copy of the Sinclair bench rest for the guys in the club but even that is a chore.
Wondering if any one else who also has been in this business for most of his life has these same feelings.

[Evan]

Al,

I have had this lathe since the early 80s. I have made a number of projects over the years but nothing major until the last few years. When I worked for Xerox I was so bagged at the end of the day I didn't feel much like doing anything. I have my own computer store now (for six years) and have been doing a lot more around the house and in the shop. One thing for sure, I never want to fix another photocopier.

You need to find something to make that is the desired end and the shop is the means to that end. My other hobby is astronomy. The shop is perfect for making astronomical instruments. This engine is the first thing that I have ever made in my machine shop that serves no useful function. I particularly like the challenge of designing my own parts/tools/devices. I haven't ever built something in my home shop to someone elses plans, yet. When I used to build model aircraft and rockets they were also my own designs. That is a lot of the fun, making your own vision real.

[dvk]

VERY impressive...