Search found 91 matches

by Alfista
Tue Sep 20, 2016 1:59 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: basic dimentions needed for gama design
Replies: 20
Views: 10244

epoxy piston

Wellington, I think that you could make a close fitting, epoxy piston work in a gamma engine. It would be quite the risk in an alpha but inexpensive to replace ! :eyeroll: Unfortunately, one could not expect an extended lifespan from it, but I believe that it would work with lubrication, and it cou...
by Alfista
Sat Sep 17, 2016 12:38 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: basic dimentions needed for gama design
Replies: 20
Views: 10244

more about piston rings

Here is a little more information on piston rings. I understand that there are many ways to build an engine but it would be a shame to dismiss the topic of piston rings as "something not used" on hot air engines. On smaller engines, it is probably an unnecessary complication. In glass cylinders, it...
by Alfista
Thu Sep 15, 2016 9:50 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: basic dimentions needed for gama design
Replies: 20
Views: 10244

choice of one's first engine

Wellington, I would encourage you to first try your hand at a gamma engine first before trying to build an alpha. The alpha poses the particular problem of building a compound piston & displacer, possibly two of them and possibly sealing a low friction, hot piston & cylinder combination. If you are...
by Alfista
Mon Sep 12, 2016 7:40 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: basic dimentions needed for gama design
Replies: 20
Views: 10244

dimensions of gamma engine


I refer you to Robert Sier's Notes on Hot Air Engines. It is probably the best one page summary to be found.


http://www.stirlingengines.org.uk/modeng/note.html
by Alfista
Mon Sep 12, 2016 6:43 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Homemade Engine with Generator
Replies: 18
Views: 11514

Re: Homemade Engine with Generator

Alfista, have you tried reversing the pulleys, putting the small one on the crankshaft, and big one on the generator, it will reduce the revs at the generator, but allow the motor to run more freely, with more torque at the generator end. Thank you for your reply Ian. Yes, I have tried that combina...
by Alfista
Thu Sep 08, 2016 10:01 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Homemade Engine with Generator
Replies: 18
Views: 11514

A photo of my homemade engine with generator


Here is a still shot.



by Alfista
Fri Sep 02, 2016 8:11 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Stirling engine project
Replies: 8
Views: 5591

Re: Stirling engine project

I have made several displacers out of aluminum. None have melted or developed problems. There are several good methods for making a displacer. Ian is right to point out the potential problems and inherent disadvantages of aluminum. That said, aluminum is very light and whereas it may be quite easy ...
by Alfista
Wed Aug 31, 2016 8:45 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Thickness of hot end wall
Replies: 3
Views: 3004

My suggestions for wall thickness


My suggestions for wall thickness

1.5" cylinder : .0325" wall
3" cylinder : .05" - .0625"
8" cylinder : .09375"

Of course higher temperatures probably need thicker material.

Good luck !

by Alfista
Mon Aug 22, 2016 3:38 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Rider and Erricson Engine Plans
Replies: 3
Views: 3387

Re: Rider and Erricson Engine Plans

Wellington, there are very nice plans for it to be found in the first volume of "Steam and Stirling Engines" published by Village Press. I am not a shill for Village Press ! :laugh: I just buy a lot of their books, and in fact, in general, I would not recommend this series which is published in thr...
by Alfista
Tue Aug 16, 2016 6:13 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Looking for a powerfull horizontal stirling engine model
Replies: 3
Views: 3731

Re: Looking for a powerfull horizontal stirling engine model

Wellington, I know that this is not what you are looking for but you can build this. It is a good first engine and it will scale up nicely. If you need the space between the bearing supports, just add a copper tube as in the video you posted. [youtube]https://youtu.be/mUr6rsNgBU0[/youtube] .562" bo...
by Alfista
Mon Jul 18, 2016 6:37 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Homemade Engine with Generator
Replies: 18
Views: 11514

reply to Ian

A couple of suggestions: if you want to try more fly wheel, You could loose a bit of weight possibly on the crank webs,  Ian, thank you for your post. You may not have noticed the last couple videos with the larger flywheel, although a bit too large at 16" it did make a nice improvement. One of the...
by Alfista
Mon Jul 18, 2016 5:58 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Homemade Engine with Generator
Replies: 18
Views: 11514

reply to Ledlights

Ledlights Thanks for your kind words about the engine. You make a good point about trying to push the engine. In the original of the load test video, the sound quality made it much easier to hear the effect of the generator load on the engine at the moment when the battery is connected to the gener...
by Alfista
Fri Jul 15, 2016 7:01 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Homemade Engine with Generator
Replies: 18
Views: 11514

Re: Homemade Engine with Generator

No, of course not. If it did, there would be no significant voltage drop.
by Alfista
Thu Jul 14, 2016 3:25 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Homemade Engine with Generator
Replies: 18
Views: 11514

Running without a load


Finally, a short clip of the engine running without a load.
[youtube][/youtube]

by Alfista
Thu Jul 14, 2016 1:59 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Homemade Engine with Generator
Replies: 18
Views: 11514

Engine and generator under load


Here is a video of the engine running, charging a battery and with an 80 watt load. I changed the 8" flywheel to a 16" flywheel and changed the generator sprocket to 20T. [youtube][/youtube]

Now the ratio is 23:20.

Thanks for watching !

Wayne