用油漆罐自制斯特林发动机

如何使油漆罐斯特林发动机Assembly Instructions (1)Make the Pressure ChamberThe finished pressure chamber will be 1 1/2” tall. It will be made from the top and the bottom of the paint can.Remove the paint can lid and mark a line around the side that is exactly 5/8 down from the top. Mark another line around the outside that is exactly 5/8” up from the bottom. Cut carefully along this line. Cut carefully so that you also preserve the center section of the can. You are going to use the center section to cut some additional parts.I use a sheet metal nibbler to cut my paint cans. I drill a small hole (about 1/4”) to start the cut, insert the nibbler, then work my way around the can.Use tin snips to cut the center band of the paint can. Make a vertical cut parallel to the weld that is in the side of the can. Measure and cut a strip of metal from the bottom of the can that is exactly 1 3/16” tall. This cut is parallel to the cut made when you removed the bottom of the can. This piece of metal will be used to make the pressure chamber sidewall.The pressure chamber sidewall will be glued to the inside of the top and bottom can parts. Use the high temp silicone glue for this. Glue all three pieces together at the same time (top, side, and bottom). Start by gluing the sidewall to the inside of the pressure chamber top. (The top is the piece with the lid.) Use enough silicone to get an air tight seal everywhere. I used a small piece of metal (about 1/2” x 1 1/8”) to reinforce the seam in the sidewall. Set this assembly aside until the glue is completely cured.Make a DisplacerThe displacer is cut from a piece of 3/16” thick foam core poster board. Measure the opening of the paint can. The displacer will have to fit into this opening, so it must be made a little smaller. Use a compass to mark a circle on the poster board that is exactly 1/8” smaller in diameter than the opening of the paint can. This will provide 1/16” clearance between the edge of the displacer and the opening of the can. Cut carefully on the line.Cut a 3” piece of 1/16” music wire. The easiest way to cut music wire is to score it with a file and then bend it and break it. Good quality music wire is very hard and will break like tool steel when it is scored and bent. Place a 90 degree bend in the music wire 3/4” from one end. This bend should be as close to 90 degrees as you can get it to be. If you have a drill press you can use it to create a simple jig for gluing the displacer rod to the displacer. Simply drill a 3/32” hole through a flat board. This hole will hold the displacer rod at the correct angle while the glue is curing.Press the long end of the displacer rod through the center of the displacer and down through the hole in the jig. Apply enough pressure to compress the poster board just a little bit around the center. Fill the depression with epoxy glue and set it aside until the glue has cured. Once the glue cures remove the assembled part from the jig and check the alignment. The rod must be perpendicular to the surface of the displacer and in the exact center of the disk.Prepare the Drive CylinderDrill a 7/16” hole in the center of the bottom of the film can. This hole is drilled to fit the short pipe nipple that is used to connect the drive cylinder to the pressure chamber lid.Drill a hole in the center of the lid and carve it out until it is as large possible, until only a ring remains. This ring will be used to seal the diaphragm to the drive cylinder.Prepare the Pressure Chamber Lid Use a compass to find the center of the paint can lid. To do this, set the compass to match the radius of the lid, and then use it to draw a line near the center of the lid. Rotate the lid 90 degrees and repeat the process. Continue to rotate the lid and draw marks with the compass until you have established the center point of the lid.Drill a 1/4” hole through the center of the lid.Locate the position of the drive cylinder. The drive cylinder will be positioned as close to the edge of the lid as possible while still being mounted to the flat surface of the lid. Mark the position of the hole using the film can as a guide. Drill the hole with a 7/16” drill bit.Make and Attach the Pressure Chamber GlandThe “gland” allows the displacer rod to pass through the top of the pressure chamber without causing a leak and without creating significant friction. UHMW plastic is a good choice for this purpose. It is naturally slippery.Cut a piece of UHMW plastic to be 1” x 1” x 3/8”. Locate the center of the square and drill a 1/16” hole using a drill press (if you have one). Test the fit with a piece of 1/16” music wire. If it is a snug fit that does not allow the music wire to slide easily, the hole must be enlarged. Increase the drill size by 1/64” (to 5/64”) and drill it again. Test the fit again. 1/16” music wire is actually slightly oversized and should be a good match with a 5/64” hole.Use RTV silicone to attach the gland over the center hole of the lid. Keep the silicone away from the center hole in the UHMW as it will cause friction if it gets in the way of the displacer rod.Assembly Instructions (2)Attach the Drive CylinderUse RTV silicone, the pipe nipple, and the hex nuts to attach the film can to the paint can lid. Place enough silicone around the hole to provide an air tight seal. Set the hex nut on the inside of the lid so that very little (as little as possible) of the tube protrudes into the pressure chamber. It is OK if a little extra tube protrudes into the film can. But you want to maintain as much clearance for the displacer as you can.Make and Attach the Crank Shaft TowerOpen a can of chili. Heat and serve the chili. Now get back to work on the engine. Wash out the can and remove the bottom of the can with a can opener.Drill or punch two holes near the top of the can. These will be your crank shaft bearings. The holes should be about 1/64” larger than the diameter of your coat hanger wire. The holes need to be as even as possible so that the crank shaft is level when mounted.Cut access holes in the front and back of the can. The access holes are about 2” wide and about 3 1/4” tall. The chili can is mounted to the top of the pressure chamber lid with small metal brackets and 5 minute epoxy. Cut some small scraps of tin from the paint can scraps and bend them to 90 degrees and use them to brace the can in place.The can needs to be aligned so that it is centered over the gland. The crank shaft needs to be centered over the drive cylinder. Place a piece of straight coat hanger wire in the bearing holes so that you can easily check the alignment as you glue the chili can in place.Make a Shaped Drive Diaphragm from the Vinyl GloveThermoforming allows you to create a flexible vinyl diaphragm that is shaped perfectly to fit the drive cylinder (film can) and the piston assembly. This makes for a very efficient drive mechanism that is free of leaks and offers very little friction.Create a small vacuum table by drilling some 1/8” holes in a thin piece of wood and attaching a vacuum cleaner hose. It doesnt have to be fancy. It just has to be big enough to support the pieces for this project.Cut a film can to create a tube that is 3/4 inches long. This will be the “form” for the thermoforming process.Cut a vinyl glove to create a flat sheet of vinyl fabric. Stretch the vinyl over a frame to hold it flat for the thermoforming process. In the illustrations here the vinyl is held on the end of an empty roll of masking tape.Place the form upright on the vacuum table and switch on the vacuum. Use a heat gun or a hot hair dryer to warm the vinyl fabric. When the fabric becomes relaxed and smooth it is ready to be pressed over the form. Press it down onto the form and allow the vacuum to pull it to the shape of the form. Remove the heat. Allow 10 to 20 seconds for the vinyl to cool and then switch off the vacuum. Remove the vinyl from the form and trim off the excess material.The piston is made from two flat disks cut from a disposable coffee cup lid. Use a quarter to trace two circles on the lid and carefully cut them out with scissors. Mark the center of each disk and drill a hole to fit a #4-40 x 1” bolt.Place one disk on the inside of the shaped diaphragm, and place the other on the outside. Place a small drop of silicone between the plastic disks and the vinyl. Use a sharp object to carefully pierce the vinyl at the center of the disks. Pass the #4-40 x 1” bolt through the outside disk, through the vinyl, and through the inside disk. Thread a bolt onto the shaft and hand tighten it to hold the piston assembly and diaphragm together. Place two more nuts on the bolt and set it aside until the glue cures.Make the Crank ShaftCut a piece of straight coat hanger wire so that it is 7” long. The first crank will be over the center of the engine and will lift the displacer. The second crank will be over the drive cylinder and will be connected to the drive piston. The two crank sections are offset by 90 degrees. As the crankshaft rotates the second crank is following 90 degrees behind the first crank.The first crank allows the displacer to move to within 1/16” of the pressure chamber top and bottom. If your paint can went together like this one, there will be about 3/4” of travel available to the displacer. But you should measure to be sure. The formula for determining the size of the offset for the first crank is: Offset=(DT-1/8”)/2 where DT = Displacer Travel. So if your displacer travel is 3/4” it would look like this: Offset=(3/4”-1/8”)/2. The answer in this case is 5/16”. The first crank must be 5/16” from the centerline of the crank shaft.The second crank over the drive piston will have a 1/8” offset, which means the drive piston will have a total traveling distance of 1/4”. Remember that there is a 90 degree offset between the two cranks.Draw two parallel lines on a sheet of paper that are the same distance apart as the offset for the displacer crank. Use these lines as a guide in bending the coat hanger wire. Work with diligence to insure that all sections of the crankshaft are parallel and true.Draw two parallel lines on a sheet of paper that are 1/8” apart. Use these as a guide for bending the section of the crank shaft that attaches to the drive piston. Remember that there is a 90 degree offset between the two crank sections, and that each segment must remain straight and true to help prevent friction and wobble.Install the bent crank shaft in place on the chili can.Make and Attach the FlywheelUse sandpaper to remove the non-stick coating from the inside center of a paint can lid. Use epoxy to glue a small block of wood to this bare spot in the center. After the glue cures you can carefully drill a hole in the wood. (Use the compass again to find the center of the flywheel.) This hole should be a snug fit for the coat hanger wire. Attach the flywheel to the end of the crank shaft.Assembly Instructions (3)Make and Attach the Connecting RodsThe first step is to create an attachment point for the top of the displacer shaft. The music wire is very stiff and difficult to work with in tight places, so I prefer to not bend the top of the displacer shaft. I make the top piece from soft craft wire that is easy to form. For this application I formed the hook shaped wire on another piece of music wire, then slipped it off and placed it on the displacer shaft. It is held in place with a small drop of epoxy. If I ever need to, I can disassemble the pieces to take it apart and work on it.I use the same soft craft wire to make connecting rods for the drive piston and for the displacer. The displacer connecting rod has a “Z” bend in it. This is to simplify the adjustment process. If the shaft needs to be adjusted in length, simply grab the middle of the “Z” and give a slight twist to make the shaft slightly longer or shorter.2011-4-20 05:32 上传下载附件 (67.79 KB) The shaft connecting the drive piston to the crank shaft does not need to have the “Z” twist because it can be adjusted by moving the nuts up or down on the bolt that holds the piston together.Assemble the EngineSecure the lid to the pressure chamber body by pressing it into place. Do not bang on it with a hammer. Pounding with a hammer will dent the lid and cause a leak. If you feel it must be tapped into place, put a block of wood over the seam and tap the wood lightly with a hammer until the lid is seated all the way around.Attach the displacer connecting rod and adjust it so that the displacer does not touch the pressure chamber top or the pressure chamber bottom.Attach the connecting rod from the drive piston to the crank shaft. Adjust the length of the connecting rod so that the piston can move freely. It should not go down low enough to pull the fabric of the diaphragm completely tight. And it should not go high enough to extend above the top of the drive cylinder. It should have about 1/4” of travel from top to bottom.Make a StandThe stand that is pictured here was made from another paint can. (But you can get quite creative if you like. The video of the first running of this engine shows it perched between two soup bowls.) The paint can stand works well. The top is open because the lid from this can was used to make the flywheel. A large hole is cut in one side of the can. The hole does not extend all the way to the top of the can. This is so the hot air from the candle will be trapped in the top of the chamber. The candle used in these illustrations is s liquid wax candle. It is not quite as hot as a wax candle, but it burns very clean and will last for about 24 hours of burn time if you dont modify it. If you want a larger flame you can pull the wick a little higher. The instructions on the candle advise against this, so be careful.Fire It Up!Lubricate the crank shaft at every point where it comes in contact with another piece of metal. Use light 3-in-1 oil. Place a drop of the same 3-in-1 oil on the displacer shaft. This will lubricate the shaft as it passes in and out of the gland, and will also help prevent pressure leaks through the gland. Light up the candle and place it in the stand. Put the engine on top. Let it warm up for about 30 seconds and then rotate the flywheel to start the engine.The direction of rotation is determined by the 90 degree offset between the displacer and the drive piston. The displacer always moves ahead of the drive cylinder. Rotate in the direction that makes the displacer reach the top 90 degrees ahead of when the drive cylinder reaches the top.The e