At 11:00 AM 5/11/99 +0100, Tony Moss wrote: >Unfortunately aluminium shrinks 3/16" per foot of pattern size when cast >so castings cannot be used as 'patterns for themselves' although it >should be possible to use them to design replacement items in steel for >modern 'shell moulding' techniques.
A good point, Tony, but I believe that these parts could be used for patterning since uniform, isotropic shrinkage of the parts would only rescale the sundial slightly in size. Since the shrinkage of every part is to the the same scale factor, they should still fit together perfectly. This is academic because such an approach would be useless for production.
