Cedge
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- Jul 12, 2007
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I've been off my feet today with a bit of a back problem but I dragged my Elbow engine inside and took the time to do some serious observation and thought. I've come up with a couple of things that are making a significant difference with the droopy piston set and the friction problem.
The first find was something that had been bothering me but I couldn't quite come up with a solution. I wanted the engine to be as "open" as possible, which meant I tried to give the gap between the drums a bit of added breathing room. this meant the pistons extended a little higher in the cylinder at full extension. It didn't seem to be a problem but after watching the action closely. it became clear this was where the droop was being born.
I moved the drums clser together, being carefulk not to move them close enough to allow the pistons to strike at the bottom of the cylinder when fully collapsed. This small adjustment improved things greatly and the droop has been almost totally elminated. The closing of the spacing meant more of the piston was retained inside the cylinder at full extension which added support and stopped it from sagging. This nearly stopped it from binding against the cylinder wall.
The other small change was to elongate and widen the screw holes where the bottom beraing blots on. This let me adjust the bearing a bit for alignment purposes. This problem was spotted when I placed a small machinist square on the base and eyeballed is against a fully extended piston. It became obvious the bearing needed to shift laterally to put the pistom on a true vertical. Yup... another friction point to watch for.
Finally... lubricant. I've used 3 in 1 oil, 30 wt, tapping oil, litium grease and WD 40, trying to find something that the little engine liked. The grease tended to make it fairly happy, but it smells badly, it's messy and it has a habit of collecting in the valve channels. The other oils were a waste of time since they washed out quickly and left me with dry metal surfaces rubbing together in an already friction proned engine.
I dropped in the local Auto Zone automotive parts store in search of something that would be as slick as a snotty doorknob, but would have some adherence properties. Three products seemed to meet the bill of requirements. A product called "Slick 50", STP oil treatment and a product that the counter guys swore was better than both. I bought something called Lucas Oil Stablizer for 10 bucks, but the quart bottle is likely to be a good 5 year supply.
This is the stuff in the little display of gears that sits on their counter. You turn the handle and the oil climbs up the gears and clings to them. The display has a mix of 80% oil and 20% of the stablizer. When I described what I wanted from the product, the counter guys said I'd found it. I brought it home, put a bit in a syringe so that I could control it and then applied a tiny bit at full strength to each piston as it came to full extension.
All I can say is WOOOWWWWW!! It's honey thick and stays on the metal, it's slick as grandma's grease and this little engine loves the stuff. I can now spin the flywheel by hand and get full sympathetic action from the lower drum, with only a small sporadic friction bump that is getting smaller and far less frequent as I work it by hand. The idea is to to wear the engine in a bit before trying it on air. That will come when my lower back decides it loves me again....LOL
Steve
The first find was something that had been bothering me but I couldn't quite come up with a solution. I wanted the engine to be as "open" as possible, which meant I tried to give the gap between the drums a bit of added breathing room. this meant the pistons extended a little higher in the cylinder at full extension. It didn't seem to be a problem but after watching the action closely. it became clear this was where the droop was being born.
I moved the drums clser together, being carefulk not to move them close enough to allow the pistons to strike at the bottom of the cylinder when fully collapsed. This small adjustment improved things greatly and the droop has been almost totally elminated. The closing of the spacing meant more of the piston was retained inside the cylinder at full extension which added support and stopped it from sagging. This nearly stopped it from binding against the cylinder wall.
The other small change was to elongate and widen the screw holes where the bottom beraing blots on. This let me adjust the bearing a bit for alignment purposes. This problem was spotted when I placed a small machinist square on the base and eyeballed is against a fully extended piston. It became obvious the bearing needed to shift laterally to put the pistom on a true vertical. Yup... another friction point to watch for.
Finally... lubricant. I've used 3 in 1 oil, 30 wt, tapping oil, litium grease and WD 40, trying to find something that the little engine liked. The grease tended to make it fairly happy, but it smells badly, it's messy and it has a habit of collecting in the valve channels. The other oils were a waste of time since they washed out quickly and left me with dry metal surfaces rubbing together in an already friction proned engine.
I dropped in the local Auto Zone automotive parts store in search of something that would be as slick as a snotty doorknob, but would have some adherence properties. Three products seemed to meet the bill of requirements. A product called "Slick 50", STP oil treatment and a product that the counter guys swore was better than both. I bought something called Lucas Oil Stablizer for 10 bucks, but the quart bottle is likely to be a good 5 year supply.
This is the stuff in the little display of gears that sits on their counter. You turn the handle and the oil climbs up the gears and clings to them. The display has a mix of 80% oil and 20% of the stablizer. When I described what I wanted from the product, the counter guys said I'd found it. I brought it home, put a bit in a syringe so that I could control it and then applied a tiny bit at full strength to each piston as it came to full extension.
All I can say is WOOOWWWWW!! It's honey thick and stays on the metal, it's slick as grandma's grease and this little engine loves the stuff. I can now spin the flywheel by hand and get full sympathetic action from the lower drum, with only a small sporadic friction bump that is getting smaller and far less frequent as I work it by hand. The idea is to to wear the engine in a bit before trying it on air. That will come when my lower back decides it loves me again....LOL
Steve
