Slowly casting up parts for a steam twin marine engine

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Artie:
Well that was an epic few weeks to get to that point and I must say that Im a little 'over' casting brass so I decided to move onto the next piece on the list, actually it wasnt next but it was aluminium so I moved it up the list to give me a break... :)

The pedestals for the crank used my CAD system to design them up... thats Cardboard Aided Design... I actually do have Alibre but for simple 2 dimensional stuff this was just too easy..

So using 3mm MDF and building up with atimber we ended up with these....

And straight out of the sand.. (again, still smokin)

Sprues and risers trimmed off...

Further triming but not yet finished, havent machined in the crank journal yet, will wait til I have the 4 of them cast and sized and do them all in 1 pass.

Artie:
And thats where we stand today, next is the cross head beds in brass and the cylinder end caps also in brass. Crank will be a built up unit and the boiler is a thread in itself as I wish to use this thing in public it needs to be insured against public injury and that means joining the local steam club and buiulding a boiler that conforms to the AMBSC codes (Australian Miniature Boiler Safety Committee).

These are quite onerous and I have already changed from steel to copper in the planning stage.. unfortunately I had already sourced the steel tubing...

Ill update this as I go along.. but it wont be fast due to various commitments..

Cheers all

Artie

Artie:
A short up date, had a couple of hours to spare today so I cast up the remaining 3 pedestals, actually I cast up 5 as I had a couple of failures. The first 2 had bad sinkback where the outlet sprue joins the top block, the previous 2 were perfect, its raining here and with the high humidity things change when casting. I altered the pour method and sprue locations slightly and all was well, the next 3 were great....

These will have main bearing caps made and mounted and then they will be bored for the crank. I plan on using a D bit reamer to size it (thanks Blogs) and shim if necessary (im hoping not).

Once rough sized these will all be clamped together and final machining will occur as a unit.

If anyone has any questions or suggestions to help improve the process, please fire away!

Rob.Wilson:
Very nice Rob :clap: :clap: :clap: :clap: :clap: :clap: great to see :thumbup:

Keep it coming :D

Cheers Rob

Artie:
Thanks Rob, Ill be away working for a week so wont be able to touch it until I get back... I think I may need a tiny collapsible mill I can fit in the boot of my car. Im itching to size these things up and a week is a long time without a metal munching fix.... :(

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