Hi Glenn,
Yea, I know, on the small ones a tiny fraction of a bind will keep the engine from running, doesn't take much. This one is as friction free as can be. Without the tube in place I can give the flywheel a push and it will make a couple rev's before it stops. The inner tube used in that way was a really stupid idea as it turned out. I made a few small diaphram type that turned out quite well and a couple that wouldn't run at all. My quest for a simple way to make a large diameter power piston continues... I have one more trick up my sleeve for a large diaphram before I give up and move back to a nicely polished large diameter cylinder and precision machined piston with exotic seals. Actually a couple ideas...
I remember seeing that some time ago, don't remember where. I used to subscribe to the Stirling news and have many years of these magazines piled up all over the place from back in the 70's and 80's. It's fun to go back and see some of the stuff that was being worked on.
I find it quite strange that no one has put together a larger unit. Andy Ross and a couple others made some mighty attempts at some reasonable power but they all seem to go to the pressurized systems and high temp engines to keep them small. Maybe I'm just kind of nostalgic but I like the larger engines with big flywheels poking along at 60 rpms or so. The little engines are fun and easy to build but they really don't do anything. The only choices are toys or big bucks for an exotic engine... nothing in between. Time for that to change... there is plenty of waste heat sources including solar to get a couple hundred watts from at a reasonable price.
I have about 50 bux tied up in my unit right now and shouldn't have to spend much if any more to turn it into a good running engine...
It's all apart and being modified and I'm hoping to have it back together next week sometime... running!
.