[ajmac]

Trouble is you can't just make a pattern from an original, Steel shrinks (unlike Cast iron) so your end casting would be a scaled down version of what you started with! The pattern maker scales up the original when he makes the wooden / resin pattern to compensate for the shrinkage. Certain items can be mouled from an original, then the moulder can 'scrape' the sand to compensate for the srinkage. A few years ago Dad did a Model T wing support in steel using an original pushed into the sand, all it needed was a couple of cm adding to its length to allow for the change in size. Obviously the entire thing was a little smaller but it was only critical on the length.