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How long life for piston graphite ??

Posted: Wed Oct 12, 2016 7:37 am
by thanh-cuibap
Hello everyone !! anyone can tell me how long life for piston graphite ??

Re: How long life for piston graphite ??

Posted: Thu Oct 13, 2016 2:04 am
by Ian S C
If the cylinder is highly polished in the bore, the graphite piston will last indefinitely, any roughness and the piston will be destroyed quickly.
Ian S C

Re: How long life for piston graphite ??

Posted: Thu Oct 13, 2016 2:24 am
by thanh-cuibap
Thanks Lan S C !

Re: How long life for piston graphite ??

Posted: Thu Oct 13, 2016 2:41 am
by thanh-cuibap
I'm improving my stirling engine and consider between piston made of graphite, aluminum and rubber membrane,. you can show me make a highly polished in the bore cylinder ??

Re: How long life for piston graphite ??

Posted: Fri Oct 14, 2016 1:30 am
by Ian S C
After you have bored the cylinder in the lathe it will have (hopefully) very light machine marks, to get rid of these start with a brake cylinder hone until the bore is an even gray all over, then you need a tight fitting piece of reasonably hard wood. Put a split in this length wise, this is so you can adjust the diameter either with a wooden wedge, or a wood screw. Coat this with fine grinding paste. With the lap mounted in the lathe chuck, and the cylinder on the lap, start the lathe and hold the cylinder with your hand and move it back and foreward, it will take quiet a while. Check that the bore is parallel. After you have finished the cylinder, then make the piston. I'v never made graphite pistons, but they are not too hade to make, initially take it down to near size, it just about to enter the cylinder, now leaving it in the lathe get some strips of ordinary paper, hold this over the piston as you would a bit of abrasive cloth over a bit of steel, the paper is enough to take off the last fraction and leave a polished surface.
Many have had success with the rubber diaphragm. Aluminium rubbing on any metal has high friction (some commercially made motors use Aluminium), the best metal is cast iron. Ian S C

Re: How long life for piston graphite ??

Posted: Fri Oct 14, 2016 2:51 am
by thanh-cuibap
Thanks Lan S C !

Re: How long life for piston graphite ??

Posted: Mon Oct 17, 2016 8:59 pm
by masaruneema
Hello everyone !! :big smile:
จีคลับ 1688

Re: How long life for piston graphite ??

Posted: Wed Oct 19, 2016 3:04 am
by thanh-cuibap
:big smile: hi !