Search found 13 matches

by czakun
Tue Aug 07, 2018 5:06 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Gamma type cylinder and displacer
Replies: 24
Views: 7171

Re: Gamma type cylinder and displacer

You right ;) English isnt my native language, thats why I may have some lacks of terminology. Sorry for that. Isnt cylinder too big? Am I right that the smaller piston is better (lighter and smaller circumference - less leaks and friction)? Amount of air pushing the piston is same coz it depends on ...
by czakun
Fri Aug 03, 2018 3:49 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Gamma type cylinder and displacer
Replies: 24
Views: 7171

Re: Gamma type cylinder and displacer

Hi after little break, collecting of materials has go forward since last time (sorry for propably incorrect verb form): - displacer is gonna be made of fused quartz test-tube (beacuse of its light weight, low conductance, and temperature durability) - material for hot cylinder and pistons cylinder i...
by czakun
Thu Jun 28, 2018 3:57 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Gamma type cylinder and displacer
Replies: 24
Views: 7171

Re: Gamma type cylinder and displacer

Ian, we stil dont understand to each other :razz: I mean that proportions 3:1 (displacer length to its diamater )and 1,5:1 (displacer cylinder volume to power piston cylinder volume) dont define displacer cylinder volume (which means displacer stroke indirectly). Take a look at this picture: https:/...
by czakun
Tue Jun 26, 2018 4:47 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Gamma type cylinder and displacer
Replies: 24
Views: 7171

Re: Gamma type cylinder and displacer

Thanks Ian for keeping be very helpful :wink: I know there should be a gap at both ends. What were I asking was about proportions of displacer length to its stroke. I have ordered tubes today. Unfortunately I couldnt find seamless, so I bought welded ones with dimensions 26,9x1,6mm and 25x1,5mm. Wil...
by czakun
Sun Jun 24, 2018 5:08 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Gamma type cylinder and displacer
Replies: 24
Views: 7171

Re: Gamma type cylinder and displacer

But aim for as long, within reason connecting rod to reduce side pressure of the piston against the cylinder wall. I'm not sure what exactly do you mean... Can you please tell what about displacer cylinder smoothness? Should it be rough to maximize temperature exchange surface? Can someone please a...
by czakun
Thu Jun 21, 2018 2:39 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Gamma type cylinder and displacer
Replies: 24
Views: 7171

Re: Gamma type cylinder and displacer

And what do you think about displacer volume to its cylinder volume? I mean what about displacer stroke when you got displacer with given, particular dimensions?
by czakun
Tue Jun 19, 2018 4:10 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Gamma type cylinder and displacer
Replies: 24
Views: 7171

Re: Gamma type cylinder and displacer

OK, lets say there is a gamma Stirling engine with 20x60mm displacer. The swept volume of displacer cylinder should be 1.5 of swept volume of piston cylinder. Thats theory. 1) These considerations dont define these volumes, just the ratio between these. What about displacer stroke and its cylinder v...
by czakun
Tue Jun 19, 2018 2:11 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Gamma type cylinder and displacer
Replies: 24
Views: 7171

Re: Gamma type cylinder and displacer

Another problem occured. Which is better: long displacer cylinder with small diamater or short with bigger diameter? Both with same volume
by czakun
Tue Jun 19, 2018 1:58 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Gamma type cylinder and displacer
Replies: 24
Views: 7171

Re: Gamma type cylinder and displacer

Thanks Ian, you are very helpful :razz:
by czakun
Sun Jun 17, 2018 5:16 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Gamma type cylinder and displacer
Replies: 24
Views: 7171

Re: Gamma type cylinder and displacer

Ok I will look for tubes as thin as possible. For now I've only found 1mm with diameter I want (about 20-24 mm). I guess its not possible to lathe it to 0,25-0,5mm? Which ones are better annealed or not annealed? I've found video with another approach where autor is soldering the end of cylinder (ma...
by czakun
Sat Jun 16, 2018 5:56 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Gamma type cylinder and displacer
Replies: 24
Views: 7171

Re: Gamma type cylinder and displacer

Thanks for your reply ;) Didnt know the underpressure inside is big enough to collapse aluminium tube! Another problem has occured. As there are only "both-side opened pipes" to purchase (should just say a "pipe"? :eyeroll:) how could I close it? With kind of metal sheet? How to do that? EDIT How th...
by czakun
Sat Jun 16, 2018 4:07 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Gamma type cylinder and displacer
Replies: 24
Views: 7171

Gamma type cylinder and displacer

Hi all, I'm preparing to make my first Stirling engine. It's gonna be gamma type. Cylinder and displacer gonna be made of some kind of metals instead of- popular in that purpose- glass test-tubes which are hard to find in suitable dimensions and are easy to damage. Got doubt about it. What features ...