Solution
MicroCentric replaced existing counter-weighted power chucks with HSC-Z chucks. Since the HSC-Z chuck maintains a greater percentage if its initial chucking force as machine spindle speeds increase, it was possible to lower the initial (static) chucking pressure. This eliminated the distortion previously seen on the valve body, and reduced the rejection rate of parts which did not meet the 7,5 micron roundness tolerance.
Achieved concentricity: 0,006 mm
Achieved accuracy: 0,005 mm