aluminum piston and or cylinder

[Fly_25R]

Hi I am trying to make my first stirling engine, and i cant decide what material to use.
i have a lot of aluminum i can cast and it would be best if i could use it.
I know it has a high coefficient of friction but i was hoping i could use it if i anodized it
and oil the engine.

I am making a 2.5 inch bore gamma engine. i hope to be able to utilize enough power to run a belt drive blower.
There were plans for one that made 1/8 hp and it is perfect

I can also cast bronze and i have a large lathe and welder and an assortment of other tools.

[staska]

Hard anodized alumium and ptfe is on of the classic solution for stirling engines.

[Fly_25R]

so ptfe rings on piston?

[staska]

Yes.

[Fly_25R]

where do you get them?

[staska]

I just make them.viewtopic.php?f=1&t=5223&start=15

[Fly_25R]

how do you make them?
teflon strips?

[staska]

Ok. Which technical capabilities do you have ?

I turn them from stock, or cut disc in washer form from thin sheet.

https://www.google.com/url?q=https://co ... tG4BFvUh7f

Page 124 will show you an easy to make ptfe cup seal

[Fly_25R]

what is better? rings or cup seal
what do you mean by "technical capabilities"?

[staska]

Technical capabilities - how big and good lathe do you have. Ie - i cant make good cast iron finishi, i have to give it for honing/polish. But alu is ok.

Cup seal or rings - cup seal is so much easier to make. But it is limited for 3-5 bar difference max. And wotks as one way valve too.