Search found 28 matches

by spinningmagnets
Thu Aug 07, 2008 2:17 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: displacer gasket insulating material?
Replies: 6
Views: 9669

Thanks, Jan.

I will keep this in mind. I know the space shuttle has insulating tiles that are replaced every trip, so the old ones are sold to tourists very cheap, but they would be awkward to cut and use.

I may just put an engine together, and then add the insulating gasket later.
by spinningmagnets
Mon Aug 04, 2008 2:56 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: displacer gasket insulating material?
Replies: 6
Views: 9669

displacer gasket insulating material?

I read a post that indicated when a running Gamma had its displacer cylinder made thinner by machining, and it reduced the heat flowing over to the cooler side. After this, the hot side was hotter, and the cool side stayed cooler, leading to a more powerful engine. (I also plan on using the flywheel...
by spinningmagnets
Sun Aug 03, 2008 8:30 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Will water or ATF absorb helium?
Replies: 1
Views: 4959

Will water or ATF absorb helium?

I am contemplating the problems with using helium as the medium in a Stirling to see if its worth the trouble. I believe the displacer can be moved with external magnets, so there will be no possible shaft seal leakage from the displacer cylinder. This leaves the power-piston rings and the power pis...
by spinningmagnets
Sun Aug 03, 2008 4:02 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Commercial uses for Stirling Engines(?)
Replies: 10
Views: 52488

possible Stirling uses

I believe it may be possible to design a large Stirling that can use solar power from a large dish or parabolic troughs, and a fan-cooled cold end with a water mister. I think it could power a small generator to charge a battery, pump water, or run a small mechanical air-conditioning unit. Steam req...
by spinningmagnets
Sun Aug 03, 2008 3:39 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Dual Acting Cylinders
Replies: 27
Views: 27079

Double-acting?

SScandizzo, the force of the piston is PSI X square inches of area of the piston face. In a double acting cylinder, the cross-section of the rod takes up a small amount of area. So, when retracting it will have slightly less power than extending. The Stanley steam car had two double acting cylinders...
by spinningmagnets
Sun Aug 03, 2008 2:02 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: why do most models have of displacer type piston?
Replies: 2
Views: 6543

I agree with everything Stephan has said, and I would like to add one more thing. The power-piston ring-seal is dynamic, and must seal while sliding in the cylinder. The way to get more power from the same size of engine is to go to higher pressures, but leakage past the power piston seals results i...
by spinningmagnets
Sun Aug 03, 2008 1:36 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: increasing displacer 'dwell' time
Replies: 14
Views: 21342

Ooops!

Sorry, jesterthought, I hadn't read your post yet. Two separate guys independently invented the telephone at the same time. Bell patented it first, can't remember the name of the other guy. He probably was headed out to the patent office before Bell, but first he had to drive his wife to the store i...
by spinningmagnets
Sun Aug 03, 2008 1:29 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: increasing displacer 'dwell' time
Replies: 14
Views: 21342

oval gears increase displacer dwell

I recall a patent about 100 years old using oval gears to increase dwell time of a double acting steam piston. I Googled "oval gears' and one link looked useful: http://decidedlyodd.com/cw/cs285/log.html As for camming, I would start the first prototype with a vertical displacer (for visualizat...
by spinningmagnets
Sun Aug 03, 2008 10:32 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Stirling engine go-kart?
Replies: 12
Views: 26795

Stirlings are safer than steam engines, and were invented because of steam boiler explosions in the early days. The problem is that that at a lower pressure, you must have a bigger engine to achieve the same power. Dustin made a 2-1/2 HP Gamma Stirling, which is roughly equal to the power of a gasol...
by spinningmagnets
Sun Aug 03, 2008 10:04 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: 4 cylinder tin can engine
Replies: 6
Views: 10217

multi-cylinder layouts

There are so many options depending on what your goals and preferred compromises are. If you want 4 power pistons... Having a single-throw crankshaft means you must use a cylinder layout that resembles a 4-spoke wheel. having a 2-throw crank means you must use a flat four layout similar to a VW bug ...
by spinningmagnets
Sun Aug 03, 2008 9:07 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Liquid nitrogen cooling
Replies: 2
Views: 5703

cold from de-compression engine

I hadn't thought of this before, but I think its worth consideration. I've worked with liquid nitrogen (LN2) and its very expensive. It is transported in a vacuumed double wall thermos container. A small amount of LN2 would make a large volume of cold gas, and coupled with a folding solar dish, it w...
by spinningmagnets
Sun Aug 03, 2008 8:32 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: I've started building my walking beam 55 gallon drum
Replies: 25
Views: 24486

Some ideas to kick around...

I "think" LTD is low-temperature-difference. If you look at picture galleries, the LTD Stirlings dont make much power (can run on the heat of your hand or a cup of coffee!). They need to emphasize heat exchange, so the displacer cylinder is a pancake. Why can't the hot and cold side be two...
by spinningmagnets
Sat Aug 02, 2008 7:45 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: tincan stirling gramophone
Replies: 7
Views: 12003

1915 Swiss Gramophone Gamma Stirling

Here's an E-mail I recently wrote: "Dear sir, I am very pleased to find your very interesting site. I believe I may have some answers about your Gramophone for your consideration, which I think is a "Gamma". http://www.dself.dsl.pipex.com/MUSEUM/COMMS/hotairgramophone/hotairgramophone...