This is a simple coke can Stirling engine you can make in under an hour. No epoxy or RTV needed, just super-glue. It's all supported by steel wire, with spade connectors for all of the bearings.
Important note: It has been found that aluminium drinks cans need additional cooling around the top because the aluminium is so thermally conductive. Use steel cans if you can, such as Pepsi, Tango etc. Scraptopower has many other plans for simple Stirling engines, have a look here.
Thanks to David Williamson for the diaphragm design/ construction method. Check out his website here!
Roll the steel wire wool around a bic pen, when it's a little bigger then the can opening, stop rolling the wool and cut it to size. Cut it down to about 2/3rds of the height of the can. Thread the paper clip you formed earlier through the centre of the steel wire wool. Tie on about a foot of fishing line to the hook in the paper clip. Squeeze the displacer into the can. It's a tight fit, but it can be done
Draw two circles on the cardboard about the same diameter as the opening in the top of the can. Don't pierce through the cardboard with the point of the compass. Inflate balloon then super glue the cardboard disc onto the balloon, there's usually a slightly deformed part of the balloon - this is roughly the centre. Glue it on here. Deflate the balloon and cut off the neck.Turn the balloon inside out. Cut off the balloon around the centre.Glue the cardboard disc over
Use a sewing needle to pierce a hole through the centre of the cardboard discs and thread the fishing line through that hole. Stretch the balloon over the can. Check that the displacer can be moved up and down freely.
Bend the two 15cm pieces upwards, these will form the bearings for the cranks. The rest of the wire is bent downwards and formed into a big circle to support the coke can. I just twisted the wires together.
Cut a piece of the steel wire about a metre long. Bend the displacer crank, this part should be bent out around 25mm.
About 5mm along from this, and rotated around by 90 degrees, start forming the two crank arms for the diaphragm.
The diaphragm cranks arms should be a short a stroke as possible, 2 - 4mm is good.
You should have about 80cm worth of wire left to form the flywheel. About 30mm from the diaphragm crank arm bend the wire in the opposite direction to the displacer crank arm. This is so you can counter balance the displacer it later on. Then about 12 cm along, start forming the circle for the flywheel.
Tie the fishing line onto the displacer connecting rod. Make sure the displacer is moved all the way up and down by the cranks without getting stuck. When your happy, super-glue the knot so it can't come undone.