Bending a spoon 100 times it will break.. Keep temp the same hot or cold no bends.. thus the tracks do not break... Its not 22Deg Celsius or 28Deg it is keeping the temp the same, as the temp changes the metal expands and contracts.. Regards Michael Cole On Thursday, October 30, 2014 1:21:22 AM John R Pierce wrote: > On 10/30/2014 1:07 AM, Cliff Pratt wrote: > > I used to work with IBM mainframes back when the dinosaurs were hatchlings. > > At one place I worked the machine was powered off on Friday at 5pm and > > powered up at 7am on Monday! Can you imagine that these days? > > > > We soon went to 24x7, but the reason was not because the users wanted it. > > It was because the engineers and systems programmers wanted time with no > > users. > > main reason I remember for keeping stuff running was, it was more > reliable if the temperature was relatively constant... temperature > flucations led to more hardware failures than any other source input > variable. > > > > --