Stirlingengineforum.com

i have made the gamma ltd engine the problem i am facing is that i have used the balloon as diaphragm the power is so low that it cant move the flywheel made of 2cds and moving on hardisk bearing i will post the pictures soon should i use a lighter flywheel

Hi, have you eliminated to the best of you ability all leaks, except just the very slightest around the gland for the displacer rod (even if you have to stick the thing in water). Eliminate as much friction as you can. Make sure that the timing is correct ie., the displacer leads the power piston by 90 degrees. Are the bearings plain or ball, if plain bearings, shorten them so that there is less area in contact with the shaft, if the bearings are say 1/16" / 1.5mm long that would be ample. Ian S C

Thanks for your help let me give the details now. Being in medical profession I call mine medical stirling engine. I am using the steel plates and in between the plastic cylinder. Displacer is made of foam used in mattress. The displacer rod is spinal needle with its sheath around. It gives a very tight sealing and free movement. I am using the size 16". The flywheel is 2 CDs attached to the harddisk head bearing. Movement is free but i think it is too heavy. As I have given more weight by attaching carom striker on either side. The rods to move this fly wheel from the displacer and diaphragm are again spinal needles. To check the system leak i have attached a cannula 16" on top plate where i can inflate the air trough its valve to check the seal and even i can produce some pressure in the chamber. But still I am waiting for the damn thing to move. I am sorry for not being able to give the pics but soon will upload.

Have you balanced your flywheel? You must add a little weight to balance against the weight of the displacer. A small coin and a piece of tape are a great way to start.

Despite the fact that you can get some pressure in there, there could still be an air leak. The pressure changes
when the engine is running normally a quite slow, so the small air leaks have a bigger effect.

Also are the cranks offset at the correct angle ?

You need a rigid, light weight foam, ie polyurithane for the displacer, rather than the foam rubber from a matrass.
The plates top and bottom are usually made of aluminium rather than steel.
With the displacer disconnected from its crank, does it fall freely if you lift it and let it go? Ian S C

Great to tell you that with the help of this forum and few others on the net I got the engine running finally. I enjoyed its first flight, and every bit of it. You can see that here http://www.youtube.com/watch?v=_PejtxgESLU

Sorry
http://www.youtube.com/watch?v=wIEHJTd1fQg
Please check the video here i accidentally deleted the previous video and uploaded a better one