HEIDENHAIN ND 730 v.3 - Manual (Page 36)

37
Multipoint Axis Error Compensation
If you want to use the multipoint axis error compen-
sation feature, you must
• Activate this feature with operating parameter P40
(see "Operating Parameters").
• Traverse the reference marks after switching on the
display unit.
• Enter a compensation-value table.
Entries in the compensation value table
• Axis to be corrected: X, Zo or Z
(Zo only ND770)
• Axis causing the error: X, Zo or Z
(Zo only ND770)
• Datum for the axis to be corrected:
Here you enter the point starting at which the axis with
error is to be corrected. This point indicates the absolute
distance to the reference point.
Do not change the datum point after measuring the
axis error and before entering the axis error into the
compensation table.
• Spacing of the compensation points
The spacing of the compensation points is expressed as
2
x
[µm]. Enter the value of the exponent x into the
compensation value table.
Minimum input value:
6 (= 0.064 mm)
Maximum input value: 20 (= 1052.672 mm)
23 (= 8388.608 mm)
Example: 900 mm traverse and 15 compensation points
results in 60.000 mm spacing between points.
Nearest power of two: 2
16 [µm] = 65.536 mm
Entry in compensation value table: 16
• Compensation value
You enter the measured compensation value (in
millimeters) for the displayed compensation point.
Compensation point 0 always has the value 0 and
cannot be changed.
Multipoint Axis Error Compensation
Your machine may have a non-linear axis error due to factors
such as axis sag or drivescrew errors. Such deviations are
usually measured with a comparator measuring system (such
as the VM 101). This allows you to determine, for example,
the screw pitch error
[X = F(X)] for the X axis.
An axis can only be corrected in relation to one axis causing
the error. You can create a compensation value table for each
axis, with each table containing 64 compensation values.
The compensation value table is selected with the SPEC FCT
key and the dialog "PARAMETER/CODE".
To determine the compensation values (e.g. with a VM 101),
the REF display must be selected after selecting the
compensation-value table.
Select REF display.
The decimal point in the left display field indicates that the
displayed values are referenced to the reference point. If the
decimal point blinks, the reference marks have not been
traversed.
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