Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

No problem.

The next job of course is testing them.

To do that, I bored a hole in a piece of maple to accept a brass tube, and drilled intersecting holes to press fit the valve bodies in place.

For a piston, I plugged one end of a 3/8 inch brass tube with a cork, and used the next larger size for a cylinder liner. Using nothing for piston rings there is of course a fair amount of air leakage, but with that said, using a bit of fuel tubing for a pickup line, i experimented with stroke lengths etc, with a feel for how much effort was applied. Frankly, is almost impossible to feel the water resistance when pulling back the piston or pushing it forward. With no outlet line attached, I managed to miss the kitchen sink a few times, but the pump drained a jelly jar of water with strong squirts, as fast as I could pump it.  The required effort is so little, I’m thinking of extending the stroke length of the pump I have in mind.  The next job is experimenting with piston rings. I’ve got a couple of ideas.

In any event the check valves worked a treat.  If you are going to use them for steam, I’d want to solder them. For water, thick CA is plenty strong.