HEIDENHAIN TNC 640 (34059x-01) Cycle programming User Manual

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Touch Probe Cycles: Automatic Kinematics Measurement

.4 MEA

URE KINEMA

TICS (Cy

451, DIN/ISO: G451; Option)

Notes on log data

Error outputs
In the Test mode (Q406=0) the TNC outputs the accuracy that can be
attained by optimization and/or the accuracies attained through
optimization (Mode 1).
If the angular position of a rotary axis was calculated, the measured
data is also shown in the log.

Dispersion (standard deviation)
In the log, 'dispersion', a term from statistics, is used as a measure
of accuracy. Measured dispersion (measured standard deviation)
means that 68.3% of the actually measured spatial errors are within
the specified range (+/–). Optimized dispersion (optimized
standard deviation) means that 68.3% of the spatial errors to be
expected after the correction of the kinematics are within the
specified range (+/–).

Evaluation of measuring points
The valuation number is a measure of the quality of the selected
measuring positions. The higher the valuation number, the greater
the benefit from optimization by the TNC. The valuation of any rotary
axis should not fall below a value of 2. Values greater than or equal
to 4 are desirable.
The valuation numbers are independent of the measured deviations.
They are determined by the kinematics model, the position and the
number of measuring points per rotary axis.

If the valuation number is too small, increase the
measurement range of the rotary axis, or also the number
of measuring points.