Graphite has a very low coefficient of thermal expansion. Therefore, as the cylinder heats up, the gap can increase. This can lead to a loss of power when the temperature rises. Then you also need to use a material with low thermal expansion for the cylinder.
Thanks you very much for this valuable information. I will do some investigation into these types of materials and possibly modify the engine in the future. I'm guessing that glass might have low expansion. I see that used on many manufactured engines. Thanks again for your important comment. I also quickly discovered this web site. www.msesupplies.com/pages/list-of-thermal-expansion-coefficients-cte-for-natural-and-engineered-materials Best Regards: Larry
@@larrypoindexter9351 I also work with Stirling engines, only more powerful. I can share my experience. studio.ua-cam.com/users/videowoSKAygQWvQ/edit/basic
I did some searching thru my garage and came up with my bucket of 11L17 flat stock. The width varies from 3/4 to 1 1/4. Is there anything different that you would do with your tool post design if you could do it over. Would you consider a larger post diameter. I have some round Ductile Iron for the center post and base. My thought is to make the post and base from one piece.
John: I'm very happy with what I have. Walter Maisey also some videos on his tool post and it pretty much the same as mine. There is one thing. Make sure the tool holder hole has a very close fit on the post. Otherwise you could have trouble tightening and closing the band sawed slot. Kilroy made a large standard version and had some problems in that area, and I found it holds true on the scaled down version. Good Luck: Larry
I totally agree with making the center post very solid. My plan is to turn the center post from 80K Ductile Iron. Very strong with great bearing qualities. By using a one piece design I will pass on making the indexing option at the base. I will make the base large enough in diameter so that I can attach bolts to both table slots.
@@johnwalters6800 I've been using the current design for awhile and haven't any real problems. My friend Walter Maisey has also had good luck. I only have one tool holder that's hard to tighten because of the problem I mentioned earlier. I hope you've Watched Walter's Videos on UA-cam where he uses a little heavier center hold down and sturdier T-Nut than I did. I am glad that I case hardened the serrated indexable base piece. Walter didn't do that, but tries to be careful not to damage the serrations. Well.......Good Luck with your design and Best Regards: Larry
Martin: I made a graphite and aluminum piston for my "Fizgig" engine and ended up using the aluminum piston. My friend in Canada purchased some hard to get parts from an engine plans seller sometime in past history. Graphite has other uses and is sold by certain people for fishing rods and stirring sticks, etc. I was able to find a piece on Ebay that was 7/8" dia. x 6" long that worked for my purposes (I think it was sold as a stirring stick. As far as the UK, I'm not sure, but you can find it in the US (Ebay) and maybe just a search on Google. Here's an Ebay Link: www.ebay.com/itm/221005884903?hash=item3374fa2de7:g:co8AAOSwo49fAiTC which probably won't help you, but gives the idea. Regards: Larry
Well done! Graphite certainly has different characteristics compared with "other materials" (steel?). What makes it perform better than the first piston? What was Your theory? Less loss of heat energy? The engine runs a bit more slow You tell. Anyway, "It's a alive"!
Everyone says graphite makes the best piston. It's lighter and if hollow even better. It doesn't require any lubricant and probably wears very little. Its properties I don't think change with temperature. I would guess it's the ideal material. Of course I'm no expert, but figured it was worth a try. It is critical, so if the aluminum were to wear then I would need to replace. I would guess the piston is one of the most critical parts of the engine. Regards: Larry
@@larrypoindexter9351 Both a piston and a cylinder will generally wear but if the piston is more "friendly" both will likely wear less. Anyway, really nice the project went well and the engine also runs well.
@@larrypoindexter9351 As Your skill is way higher then mine Your videos now and then give me tips I can use in my kitchen shop. Being a member of a railroad club restoring real steam engines I learn things all the time, and can only admire the work done in that shop. You do the same even for small engines. A link: www.agj.net
Graphite has a very low coefficient of thermal expansion. Therefore, as the cylinder heats up, the gap can increase. This can lead to a loss of power when the temperature rises. Then you also need to use a material with low thermal expansion for the cylinder.
Thanks you very much for this valuable information. I will do some investigation into these types of materials and possibly modify the engine in the future. I'm guessing that glass might have low expansion. I see that used on many manufactured engines. Thanks again for your important comment. I also quickly discovered this web site.
www.msesupplies.com/pages/list-of-thermal-expansion-coefficients-cte-for-natural-and-engineered-materials
Best Regards: Larry
@@larrypoindexter9351 I also work with Stirling engines, only more powerful. I can share my experience. studio.ua-cam.com/users/videowoSKAygQWvQ/edit/basic
@@ВикторЗакомолдин-в8ж Thank You for sending the link. I will definitely investigate. Thanks Again: Larry
graphite is an excellant thermal conductor and going from aluminum to graphite would affect performmance due to that.. is it a graphite composite?
I did some searching thru my garage and came up with my bucket of 11L17 flat stock. The width varies from 3/4 to 1 1/4. Is there anything different that you would do with your tool post design if you could do it over. Would you consider a larger post diameter. I have some round Ductile Iron for the center post and base. My thought is to make the post and base from one piece.
John: I'm very happy with what I have. Walter Maisey also some videos on his tool post and it pretty much the same as mine. There is one thing. Make sure the tool holder hole has a very close fit on the post. Otherwise you could have trouble tightening and closing the band sawed slot. Kilroy made a large standard version and had some problems in that area, and I found it holds true on the scaled down version. Good Luck: Larry
I totally agree with making the center post very solid. My plan is to turn the center post from 80K Ductile Iron. Very strong with great bearing qualities. By using a one piece design I will pass on making the indexing option at the base. I will make the base large enough in diameter so that I can attach bolts to both table slots.
@@johnwalters6800 I've been using the current design for awhile and haven't any real problems. My friend Walter Maisey has also had good luck. I only have one tool holder that's hard to tighten because of the problem I mentioned earlier. I hope you've Watched Walter's Videos on UA-cam where he uses a little heavier center hold down and sturdier T-Nut than I did. I am glad that I case hardened the serrated indexable base piece. Walter didn't do that, but tries to be careful not to damage the serrations.
Well.......Good Luck with your design and Best Regards: Larry
Great work. Hi I'm making a manson engine and need to get some graphite. Can you please help where to by some in the uk.
Martin: I made a graphite and aluminum piston for my "Fizgig" engine and ended up using the aluminum piston. My friend in Canada purchased some hard to get parts from an engine plans seller sometime in past history. Graphite has other uses and is sold by certain people for fishing rods and stirring sticks, etc. I was able to find a piece on Ebay that was 7/8" dia. x 6" long that worked for my purposes (I think it was sold as a stirring stick. As far as the UK, I'm not sure, but you can find it in the US (Ebay) and maybe just a search on Google. Here's an Ebay Link: www.ebay.com/itm/221005884903?hash=item3374fa2de7:g:co8AAOSwo49fAiTC
which probably won't help you, but gives the idea. Regards: Larry
OK thanks for your help I will look there. thanks for replying.
Well done!
Graphite certainly has different characteristics compared with "other materials" (steel?). What makes it perform better than the first piston? What was Your theory? Less loss of heat energy?
The engine runs a bit more slow You tell.
Anyway, "It's a alive"!
Everyone says graphite makes the best piston. It's lighter and if hollow even better. It doesn't require any lubricant and probably wears very little. Its properties I don't think change with temperature. I would guess it's the ideal material. Of course I'm no expert, but figured it was worth a try. It is critical, so if the aluminum were to wear then I would need to replace. I would guess the piston is one of the most critical parts of the engine. Regards: Larry
@@larrypoindexter9351 Both a piston and a cylinder will generally wear but if the piston is more "friendly" both will likely wear less.
Anyway, really nice the project went well and the engine also runs well.
@@Stefan_Boerjesson Thanks for your interest and comments. Larry
@@larrypoindexter9351 As Your skill is way higher then mine Your videos now and then give me tips I can use in my kitchen shop. Being a member of a railroad club restoring real steam engines I learn things all the time, and can only admire the work done in that shop. You do the same even for small engines.
A link: www.agj.net