March 4, 2001
I've just begun a two-cylinder single-acting wobbler. I'm hoping this design will be self-starting, as I want to try an idea for a reversing lever. The engine will have a 7/16" bore (because that's my largest reamer at the moment) and a 3/4" stroke. So far I've roughed out the base of 1/4" aluminum, 3"x4", and made the two cylinders.
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The intersection of the scribed lines marks the position of the drive shaft. The two cylinders are at a 120-degree angle to each other. So far there's not much to show or talk about. Hopefully, the aluminum will clean up well. |
| Here's the drive shaft, crank wheel and pin. The piston rods will connect to the pin. |  |
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A 3/16" bearing is held in the plate with Loctite. The shaft is inserted in this bearing. |
| And here's the engine so far. The cylinders are merely placed on the plate in the picture, to show their relationship to the crank wheel. |  |
Time so far: About 10 hours, including a lot of putzing around. That's enough for today. Still to do -
Build the pistons/shaft assemblies, and fit them to
the cylinders and crank wheel.
Attach the cylinders to the plate at their pivot points
with spring-loaded screws.
Drill the inlet ports in the plate and the corresponding
ports in the cylinders.
Design and build the reversing mechanism. NO. See below.
Build and attach the flywheel.
Mount the assembly on a wooden base.
Test the engine and "pretty-fy" it if the
test is successful.
It will be two weeks before I get back to this, as I have other commitments.
March 18, 2001
When I got back to this yesterday, I realized my reversing mechanism idea was flawed. Worse, the engine would not be self-starting. Seems I have to learn the hard way...
Oh well, no point in trashing the project just because it's not quite what I wanted. So I went ahead and finished it today.
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Actually, it's not a bad little engine. I set it up so it runs in only one direction (counterclockwise). But back to the drawing board for a self-starting engine with reversing mechanism. I guess I'll go with a mill type, with real valves.
