- Joined
- Dec 2, 2008
- Messages
- 971
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Hi Y'all
Almost anything goes or can be made to go. I was looking for something else and came across this old engine that I built years ago. It is crude and ugly so if you are reluctant to post a video of your first engine because you are afraid that it doesn't measure up, let me lower the standards.
This is built with a soldering torch, a file and a hand drill, out of hardware store plumbing parts and tube, but it illustrates an important fact. ANYTHING CAN BE MADE TO RUN. I have a little more experience now than I did when I built this so I decided to do some testing. Here's what I learned about getting an air engine to run:
1. It should spin freely. If anything binds up or is to tight to spin freely with the air hose disconnected, it must be loosened up. If the piston or valve core do not slide freely try honing with abrasives.
2. It must hold enough air pressure to overcome friction and inertia. If air blows by the piston or valve because of poor fit, oil may provide enough of a seal to make a difference. Start with light machine oil and move up to heavier oils such as 5w,15w, or 30w engine oil. Apply to cylinder and valve bores and put a few drops in the air input tube.
3. Valve timing must be close (not necessarily perfect). The in port should begin to open just past top dead center and be fully open as the piston reaches halfway to the bottom of its stroke and should be fully closed when the piston reaches the end of its stoke. The valve on a double acting cylinder works exactly the same. Just look at each end of the cylinder as if it were single acting.
4. There must be enough mass in the flywheel to store the inertia that will carry the engine through the exhaust stroke and back to top dead center,
That's all it takes. If you have built an engine that does not run, give it another try with these things in mind. Small boys used to do this stuff before the invention of semiconductors.
Jerry
Almost anything goes or can be made to go. I was looking for something else and came across this old engine that I built years ago. It is crude and ugly so if you are reluctant to post a video of your first engine because you are afraid that it doesn't measure up, let me lower the standards.
This is built with a soldering torch, a file and a hand drill, out of hardware store plumbing parts and tube, but it illustrates an important fact. ANYTHING CAN BE MADE TO RUN. I have a little more experience now than I did when I built this so I decided to do some testing. Here's what I learned about getting an air engine to run:
1. It should spin freely. If anything binds up or is to tight to spin freely with the air hose disconnected, it must be loosened up. If the piston or valve core do not slide freely try honing with abrasives.
2. It must hold enough air pressure to overcome friction and inertia. If air blows by the piston or valve because of poor fit, oil may provide enough of a seal to make a difference. Start with light machine oil and move up to heavier oils such as 5w,15w, or 30w engine oil. Apply to cylinder and valve bores and put a few drops in the air input tube.
3. Valve timing must be close (not necessarily perfect). The in port should begin to open just past top dead center and be fully open as the piston reaches halfway to the bottom of its stroke and should be fully closed when the piston reaches the end of its stoke. The valve on a double acting cylinder works exactly the same. Just look at each end of the cylinder as if it were single acting.
4. There must be enough mass in the flywheel to store the inertia that will carry the engine through the exhaust stroke and back to top dead center,
That's all it takes. If you have built an engine that does not run, give it another try with these things in mind. Small boys used to do this stuff before the invention of semiconductors.
Jerry
