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DavidA:
Mad Jack wrote..

...If they are off significantly, you can expect lots of odd wear on the tires if you plan to run it a good bit. You might have some issues with pressure in opposite cylinders if you are way off, but I can't see that happening with the way you've mated up pieces initially....

I was wondering if the wheels would turn at all. It would seem to me that as the connecting rods on opposite pairs of wheels would have to be different lengths then due to the different between - axle centre lines, you would maybe get a kind of geometric lock effect which would prevent the wheels going around.

Dave.

DavidA:
Ron,

....A friend of mine gave me some ductile cast iron for the cyls. That stuff is nice....

I used to hate the stuff.

At work I had to machine ADI (Austenitic Ductile Iron) both manually and on a Guildemeister NC machine. We had to treat it like steel, reducing the depth of cut from the normal 1 mm per pass to 0.5 mm and flooding it with suds. If we didn't then it would turn blue very quickly.

I don't know what none austenitic is like, unless it is just like plain SG. I like that stuff nearly as much as CI.

Have fun.

Dave.

madjackghengis:
Hi Dave, the austentitic ductile iron is basically virgin cast iron, from good clean ore, with as much as thirty percent scrap steel added. It produces a cross between cast steel and cast iron, and is also known as "nodular iron", which can be machined like steel, has the lubricity qualities of cast iron, and the strength of medium carbon steel, and hardenable like such. It is commonly used in crankshafts of engines and the like, as it casts very cleanly, with little or no inclusions, yet allows the intracacies of an iron casting, that cast steel won't mimic, as it doesn't flow as nicely as iron does. The scrap steel is carefully sorted, and thus the end product is well controlled in its properties. I hope this helps a bit. :scratch: mad jack

DavidA:
Mad Jack,

Thanks for that. I must have been having a 'senior moment' when I wrote the above. I was a sampler/machinist at a metals lab and should have known that. Probably did, but like the loco picture, I have it in a mental folder I can't find when I need it. :doh:

One thing I do remember about SG is that unlike CI you can't just melt bits to make your castings as it loses some of it's constituent parts and they have to be added back into the mix when melting.

Dave.

madjackghengis:
Hi Dave, in truth, nothing re-melts like virgin metal, be it iron, bronze, brass or especially steel. Aluminum is probably the easiest to remelt and get good castings out of, just requiring good fluxing to keep porousity at bay. With the nodular iron, sharp tooling is essential, and failing that, one gets very ugly cuts with strange "hair" and no accuracy at all. The quality of the iron before the addition of the scrap mild steel is a big factor, and even a tiny piece of high speed steel will totally ruin the nodular iron, making for odd hard spots throughout a casting or forging. :bugeye: mad jack

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