There are several people building the "Poppin'" engine in "A work in progress" so I thot I would post pics of the one I put together. I made some changes to the original plans both cosmetic and mechanical. I changed the base so it didn't look so blocky. I originally made the cam follower as in the plans, although I made the roller and pivot of cast iron, but since the cam is so narrow it would skid along, not roll, so I substituted a ball bearing instead. There are 4 ball bearings in the engine, the cam follower, the two main bearings on the crank shaft and the rod bearing. all of the bearings were salvaged from computer hard and floppy drives. I removed the sheilds and washed the bearings out with acetone and I put the tinyest bit of oil on them before I run it.
The flywheels are three piece, aluminum spokes including the thin ring that is painted painted red, stainless steel rim (doesn't get rusty finger prints from inquisitive fingers), and the brass hubs the plans call for. The inside surface of the rim has a .010" step and the spokes were cooled and the rim heated and once the spokes were dropped in it was one piece.
There was a short article in Live steam magazine on a second head that captures the valve and I opted for this. The engine really needs a seperate exhaust valve if you do this, although the engine makes much more noise if you use this arraingement as when the piston comes to the top it "bangs the valve against the second head. I added more screws to the heads 'cause I like the look, took a little longer as I made all of the fasteners on the whole engine, but I am pleased how it came out. Both heads are made of stainless, the outer one with a .004" groove for the valve.
The valve is .002" stainless shim stock. When you make your valve, make several, after it runs for a while the valve on mine "wrinkles" and no longer seals. I expect the second head contributes to this, it bangs pretty hard, but it makes a cool noise
The burner is stainless to minimise heat conduction, burns ethanol (Everclear), and the wick is a rolled up piece of metal screen. The screen is from a discarded automatic transmission filter. Very fine mesh and was free for the asking, the pieces are not all that big but it is a nice screen.
The cylinder and piston are both cast iron. There are two schools of thot on to "oil the cylinder or not", I am an "oiler". I now use synthetic 0W-30W oil and the engine runs till the paint on the base begins to smoke. When the engine was first built I used moly powder for lube but after running for a while it would stop and I would have to scrub the "stuff" out of the cylinder. When I started using oil that problem stopped, the oil is sucked up past the piston and eventually is ejected out the intake port, taking the "stuff" with it. If I had a graphite piston I would not use oil.
The hardest part of the whole engine was that oiler, the body of the oiler is .25" OD glass and it was a pain in the backside to cut.
The fins do not provide nearly enough cooling and the engine gets hot enough that the base will burn your fingers which limits how long I run it. My gues would be 5 to 10 minutes. It doesn't stop as it heats up, unless it runs out of oil, but I don't want to burn the paint off it.
I made counter weight crank webs as I like the look. They are aluminum bronze bearing stock. As far as I'm concerned they could quit making the stuff, it is a bear to machine.
The next two pics show the whole engine on the cart. The tank actually holds the fuel and the handwheel under the tank is to a valve that regulates the fuel to the burner. There is silicone tubing attached to the burner so it is adjustable. The burner moves in and out as well as rotates side to side. it is pretty picky about where the flame is in relation to the intake port.
The metal work on the cart is riveted together with rivets made from copper electrical wire.
The last picture shows the scale, that is a standard disposable lighter.
The flywheels are three piece, aluminum spokes including the thin ring that is painted painted red, stainless steel rim (doesn't get rusty finger prints from inquisitive fingers), and the brass hubs the plans call for. The inside surface of the rim has a .010" step and the spokes were cooled and the rim heated and once the spokes were dropped in it was one piece.
There was a short article in Live steam magazine on a second head that captures the valve and I opted for this. The engine really needs a seperate exhaust valve if you do this, although the engine makes much more noise if you use this arraingement as when the piston comes to the top it "bangs the valve against the second head. I added more screws to the heads 'cause I like the look, took a little longer as I made all of the fasteners on the whole engine, but I am pleased how it came out. Both heads are made of stainless, the outer one with a .004" groove for the valve.
The valve is .002" stainless shim stock. When you make your valve, make several, after it runs for a while the valve on mine "wrinkles" and no longer seals. I expect the second head contributes to this, it bangs pretty hard, but it makes a cool noise
The burner is stainless to minimise heat conduction, burns ethanol (Everclear), and the wick is a rolled up piece of metal screen. The screen is from a discarded automatic transmission filter. Very fine mesh and was free for the asking, the pieces are not all that big but it is a nice screen.
The cylinder and piston are both cast iron. There are two schools of thot on to "oil the cylinder or not", I am an "oiler". I now use synthetic 0W-30W oil and the engine runs till the paint on the base begins to smoke. When the engine was first built I used moly powder for lube but after running for a while it would stop and I would have to scrub the "stuff" out of the cylinder. When I started using oil that problem stopped, the oil is sucked up past the piston and eventually is ejected out the intake port, taking the "stuff" with it. If I had a graphite piston I would not use oil.
The hardest part of the whole engine was that oiler, the body of the oiler is .25" OD glass and it was a pain in the backside to cut.
The fins do not provide nearly enough cooling and the engine gets hot enough that the base will burn your fingers which limits how long I run it. My gues would be 5 to 10 minutes. It doesn't stop as it heats up, unless it runs out of oil, but I don't want to burn the paint off it.
I made counter weight crank webs as I like the look. They are aluminum bronze bearing stock. As far as I'm concerned they could quit making the stuff, it is a bear to machine.
The next two pics show the whole engine on the cart. The tank actually holds the fuel and the handwheel under the tank is to a valve that regulates the fuel to the burner. There is silicone tubing attached to the burner so it is adjustable. The burner moves in and out as well as rotates side to side. it is pretty picky about where the flame is in relation to the intake port.
The metal work on the cart is riveted together with rivets made from copper electrical wire.
The last picture shows the scale, that is a standard disposable lighter.
