Measurement Considerations - Renishaw XK10 Manual

XK10 Hardware XK10 Software
Flatness Level

Measurement considerations

Alignment
Alignment is the process of making the laser beam parallel to the axis being
measured. This forms a datum from which the straightness deviation along
the axis can be measured. Optimal alignment reduces slope error and PSD
scale error.
Slope error
Slope error is caused by poor alignment. This can be reduced by the
following steps:
1. Minimise misalignment of the beam to the axis to reduce PSD scale error.
2. End-point fit data to remove residual slope error.
PSD scale error
Large misalignments along the axis increases PSD scale error which is
inherent in PSD technology. Aligning the beam within the advised alignment
tolerance will minimise this error.
Coning
Coning is the process of making the laser beam parallel to the axis of the
spindle being measured. This forms a datum from which the spindle pointing
error can be measured.
XK10 alignment laser system
XK10 Applications XK10 Applications Straightness
Parallelism Coaxiality
Squareness
Spindle direction
Environment
The environmental conditions during measurements will significantly affect
measurement accuracy. The factors listed can introduce noise and drift to
measurements. These should be reduced or eliminated where possible before
commencing.
• Thermal stability
• Shock and vibration
• Air turbulence
Once minimised, any further noise can be reduced using detector value
filter (see details on page 39)
Alignment tolerances
To minimise slope error and the effects of PSD scale error, aim to align the
laser beam to within the following tolerances:
Geometric tolerance
±100 μm/m* along the axis being measured
Rotational tolerance
Coning alignment should be ±100 μm/m* through a 180 degree rotation
* Environmental conditions permitting
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