Re: Creating long straight edges

I just remembered something someone told me 10 to 15 years ago that
would apply to this thread. He told me he was very good at
rebuilding large machine tools in place, ones that were to large to
ship out.

The technicque he used to scrape in the ways was to use a hand held
disk sander for the rough areas and a power and hand scraper for the
rest....

The part i remeber that was interesting was how he measured the
height of the ways for the lenght of the machine. He said the very
ends of the machine bed were usally in pretty good condition. So he
would put a couple of presion blocks on each end and stretched a
piece of piano wire over the blocks. On both ends of the wire he
placed 20 to 40 pound weights to stretch the wire tight. He then had
a precision electronic guage that would measure the distance from the
wire to the bed....

I have pondered a few times over the years how this system could work
and i have not thought of a working system i could make. Maybe the
blocks on each end were nonconductive and he used a precision block
and a feeler gauge to check for continuity. But he implied he used a
electronic insturment....

WallyK