"das" wrote in message
k.net...
Ahh yes the warm-up period. When I worked at an aerospace contractor all
the
union guys wanted to work in grinding or the toolroom. They would get to
work at 6 am, turn on the spindles and go have coffee for 45 minutes so
their machines could "warm up". I think they pushed it just a bit.

It's very possible they did, but modern machines that work in the region
around one tenth or less often need a lot more time than that to warm up.
IIRC, Wasino's S-mu lathe settled down at around two hours, which is
considered very fast at that level of accuracy (guarenteed +/- 20
millionths). And a C-frame mill of high-accuracy pretensions, such as the
Makino extreme toolroom machines of a decade or so ago, can require hours
more.

Ultimate toolroom machines, like the discontinued Wasino Wing Ace $300,000+
surface grinder, should be left running all the time.

Ed Huntress