Maximising performance

Calibration

The probe and stylus must be calibrated correctly. Renishaw has extensive experience of scanning and offers support and advice on calibration algorithms and control software suited to SP80. Please contact Renishaw for further information.

Probe deflection

Scanning deflections should be kept small, as the machine settings and application will allow loads on the probe, stylus and CMM quill to be minimised.

The probe must be operated within its calibrated deflection range. For best performance, take measurements at the mid-point of the calibration deflection limits. It is recommended that the probe is calibrated at deflections of 0.2 mm and 0.8 mm, with best measurement data then achieved at 0.5 mm.

Touch / scan speed

Performance will vary with probe speeds:

  • Longer heavy stylus combinations will require slower speeds
  • Generally, best performance is obtained at speeds less than 10 mm/sec
  • Avoid abrupt changes to CMM speed while taking measurements

Cleanliness

Ensure both stylus and workpiece are clean.

CMM maintenance

  • Ensure that the CMM has been correctly maintained and has been corrected for geometrical errors such as axis squareness, pitch, roll and yaw etc
  • Ensure that the CMM has an error map which is up to date and enabled in the control system
  • Check the system accuracy from time to time by running an ISO 10360-4 test or other similar routine
  • Regularly check the volumetric measuring performance of the CMM by using Renishaw's MCG machine checking gauge

Stylus selection

Refer to web page SP80 and SP80H stylus selection for detail.