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- Mar 1, 2010
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During my building of my 3 vertical boiler John Bogstandard pointed me at two examples of a model marine engine (see his post #73) http://www.homemodelenginemachinist.com/index.php?topic=8687.73
Bogs also provided me a link to the French plans here http://jpduval.free.fr/Moteurs_vapeur_simples/MV%20deo%2010x20.pdf Id post the copies of the photos of his version of the engine he had sent me in the PM but they dont have the Bogs Wallace and Grommet watermark so Ill leave that to him.
This was just what I needed as my next project and something I could try out my new mill on. I decided to save any posting to near then end rather than subject you lot to every cock up I was guaranteed to make. So here it is, a retrospective on a my twin cylinder double acting oscillating engine. Unfortunately I don't have a whole lot of pictures but those I do have I'll share with you as I go.
First up was my first ever milling job for the vertical pillar that forms the frame for the engine. I decided to do it in ally as I thought it would be easy to work and I have a very helpful supplier 10mins from the house.
This taught me a few things but I wasnt that happy with the result so it was eventually scrapped and started again.
Call me old fashioned but to me cylinders have to be round and anyway I cant find a source of square section brass so I decided to fabricate the cylinders from a block of brass form steam ports and round stock for the cylinder, both being silver soldered together
Steam port cradles (with the old pillar)
Milling the steam port block from brass and using a 5/8 ball end cutter produces a cradle of 15.88mm diameter in which a 16mm cylinder sits nicely centrally for the soldering.
Rather than flux up both parts and heat them up as a pair and feed in solder, which I felt would create a messy joint I took the approach of tinning the steam port block first, by fluxing it, heating it up and applying silver solder along the base of the cradle. It then went back into the pickle to clean it up . Then both the steam block and cylinder were fluxed up put together and heated up. At the point the pre-applied solder stated to flow I removed the heat and made sure the cylinder was fully seated by pressing down on it until it cooled below the melting point of the silver solder. A neat solder line could be seen between the edge of the cylinder and the steam block.
Once cooled and cleaned I chucked up the cylinder assemblies in the 4 jaw and finished off each end and made the length the 34mm on the drawing.
Pivot points, steam ports and cylinder ends were all done on the mill.
That's all folks, crankshaft and flywheel in the next installment.
Pete
Bogs also provided me a link to the French plans here http://jpduval.free.fr/Moteurs_vapeur_simples/MV%20deo%2010x20.pdf Id post the copies of the photos of his version of the engine he had sent me in the PM but they dont have the Bogs Wallace and Grommet watermark so Ill leave that to him.
This was just what I needed as my next project and something I could try out my new mill on. I decided to save any posting to near then end rather than subject you lot to every cock up I was guaranteed to make. So here it is, a retrospective on a my twin cylinder double acting oscillating engine. Unfortunately I don't have a whole lot of pictures but those I do have I'll share with you as I go.
First up was my first ever milling job for the vertical pillar that forms the frame for the engine. I decided to do it in ally as I thought it would be easy to work and I have a very helpful supplier 10mins from the house.
This taught me a few things but I wasnt that happy with the result so it was eventually scrapped and started again.
Call me old fashioned but to me cylinders have to be round and anyway I cant find a source of square section brass so I decided to fabricate the cylinders from a block of brass form steam ports and round stock for the cylinder, both being silver soldered together
Steam port cradles (with the old pillar)
Milling the steam port block from brass and using a 5/8 ball end cutter produces a cradle of 15.88mm diameter in which a 16mm cylinder sits nicely centrally for the soldering.
Rather than flux up both parts and heat them up as a pair and feed in solder, which I felt would create a messy joint I took the approach of tinning the steam port block first, by fluxing it, heating it up and applying silver solder along the base of the cradle. It then went back into the pickle to clean it up . Then both the steam block and cylinder were fluxed up put together and heated up. At the point the pre-applied solder stated to flow I removed the heat and made sure the cylinder was fully seated by pressing down on it until it cooled below the melting point of the silver solder. A neat solder line could be seen between the edge of the cylinder and the steam block.
Once cooled and cleaned I chucked up the cylinder assemblies in the 4 jaw and finished off each end and made the length the 34mm on the drawing.
Pivot points, steam ports and cylinder ends were all done on the mill.
That's all folks, crankshaft and flywheel in the next installment.
Pete