HEIDENHAIN TNC 335 Technical Manual - Manual (Page 118)

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TNC 360 1 Machine Axes 4-21
1.6 Axis-error compensation
A HEIDENHAIN contouring control can compensate for mechanical defects in the machine. The
following axis-error compensation is possible:
– backlash compensation,
– compensation of reversal errors in circular motion,
– linear axis-error compensation,
– nonlinear axis-error compensation,
– compensation of thermal expansion.
Either the linear or the nonlinear axis-error compensation can be activated. The other types of
compensation can always be activated in parallel.
1.6.1 Backlash compensation
When using linear measurement by ballscrew and rotary encoder, a small amount of play can occur
between the movement of the table and that of the rotary encoder.
Depending on the design, the movement of the rotary encoder may be advanced or retarded relative
to the table. The professional jargon describes this as positive or negative backlash.
Positive backlash: rotary encoder advanced relative to the table (traverse movement of the table is
too short).
Negative backlash: rotary encoder retarded relative to the table (traverse movement of the table is
too long).
For every change in direction of traverse, the TNC adds the value from machine parameter MP710
to value from the encoder signals.
MP710 Backlash compensation
Input range: – 1.000 to + 1.000 [mm] or [°]
MP710.0 X axis
MP710.1 Y axis
MP710.2 Z axis
MP710.3 4th axis