What is the maximum tolerance for a DIY Machine ?!

[m_c]

I miss JohnS in these kind of discussions.
I always remember a discussion somewhere (possibly on a ye olde usenet group), where somebody wanted to machine a bit steel to exactly 12" long, to within a stupid tolerance of a couple tenths.
John simply asked at what temperature did he want the tolerance met?
The guy didn't have a clue, and had to have it explained to him that for every degree of temperature change, the bar would grow/shrink by over a thou.

[JAZZCNC]

I miss JohnS in these kind of discussions.

Me too, I often see posts asking things like this and often think "I wish John was here to read this shit" . .. I can almost hear his sarcastic brutal reply's...