
15. ACCURACY COMPENSATION
FUNCTION
B–63002EN/01
NC FUNCTION
194
The errors caused by machine position, as pitch error of the feed screw,
can be compensated. This function is for better machining precision.
As the offset data are stored in the memory as parameters, compensations
of dogs and settings can be omitted. Offset intervals are set constant by
parameters (per axis). Total offset points are:
Total offset points = 128 × controlled axes.
Optional distribution to each axis can be done by parameter setting. As
each position:
Offset pulse = (-7 to +7) x (magnification)
Where Offset pulse unit is the same as detection unit
Magnification: 0 to 100 times, set by parameter (per axis)
On a machine having a long stroke, machining precision may be reduced
if the straightness of the axes is poor. The straightness compensation
function compensates an axis in detection units while the tool is moving
along another axis, thus improving machining precision.
Moving the tool along an axis (movement axis, specified with a
parameter) compensates another axis (compensation axis, specified with
a parameter), at each pitch error compensation point along the movement
axis.
Pitch error compensation points along the movement axis
… …
Example:
0 1 2 3 60 61 126 127
Machine coordinates along the movement axis
… …
ac
α
β
γ
bd
ε
a, b, c, d : Compensation point numbers for the movement axis (same as the numbers
of the pitch error compensation points)
α, β, γ, ε : Compensation value for each compensation point number
The compensation value applied to the compensation axis is (α – β)/(b –
a) for the range between points a and b.
NOTE
1 Straightness compensation is enabled once reference
position return has been performed along the movement
and compensation axes.
2 When the optional straightness compensation function is
used, the optional storage pitch error compensation
function is required.
3 Straightness compensation data is added to the storage
pitch error compensation data when output.
15.1
STORED PITCH
ERROR
COMPENSATION
15.2
STRAIGHTNESS
COMPENSATION