On Feb 5, 6:39*pm, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:
Searcher7 fired this volley in news:370407bd-
:

It's a fool's errand to try and find a metal you can work with that won't
expand and contract with changes in temperature.

Instead, you should be 'focusing' on a design where the various
dimensional changes don't affect the aim angle. *For instance, where the
camera pivots at the exact centroid of all the expansion or contraction.

That, and a solid base, like granite, to hold all the other stuff.

Even granite changes dimensions with temperature... G

LLoyd

LLoyd is correct. Theodolites are not made of metal that do not
expand or contract.


Dan