Josh,
That I am aware of, there is no carved in stone frequency. Most companies do it once a year. Your ISO procedures can state practically any frequency from 3mos. to 2yrs.
I doubt anyone pushes that limit though.You brought up an interesting point, how do you know if & when the machine may be out of calibration ?? 3 mos. after calibration someone might "crash", then what ? Renishaw
has a machine checking gauge that can help you with this. Relatively inexpensive, $3500
for this tool which can be used in dcc or manual & on any software.Contact Renishaw or your local distributor for any questions.
jnlj@home.com