
B-63944EN-2/02 PROGRAMMING 6.COMPENSATION FUNCTION
- 223 -
- Calculating a Fixture Offset values
(1) Relationship between the rotation axes and linear axes
First group : 4 (B-axis) , 3 (Z-axis) , 1 (X-axis)
Second group : 5 (C-axis) , 1 (X-axis) , 2 (Y-axis)
Third group : 0 , 0 , 0
(2) Reference angle and reference fixture offset
X : F
0X
Y : F
0Y
Z : F
0Z
B : θ
0
C : φ
0
If the above data is set up, the method of calculating fixture
offset value is as follows:
O : Rotary table center
W : Workpiece origin offset value
F
0 :
Fixture offset value when B=θ
0
, C=φ
0
F
A :
Fixture offset value (F
AX
,F
AY
,F
AZ
) when B=0, C=0
F : Fixture offset value (F
X
,F
Y
,F
Z
) when B=θ, C=φ
Then, the following expression is used for fixture offset calculation.
() ()
() ()
−−
−−−
−−−
−−
=
Z
Y
X
AZ
AY
AX
F
F
F
F
F
F
0
0
0
00
00
00
00
100
0cossin
0sincos
cos0sin
010
sin0cos
φφ
φφ
θθ
θθ
() ()
() ()
−
−
=
AZ
AY
AX
Z
Y
X
F
F
F
F
F
F
θθ
θθ
φφ
φφ
cos0sin
010
sin0cos
100
0cossin
0sincos
・If manual interventin is made on the rotation axis
When the automatic operation is stopped by the SBK stop or similar in
the G54.2 mode, and a manual movement is made about the rotation
axis, the vector of the fixture offset does not change. When a rotation
axis command is specified in automatic operation or in MDI operation
or When G54.2 is specified, the vector is calculated.
When manual intervention is performed with parameter ABS (No.
7570#1) =0 and in the manual absolute switch is set on and then a
rotation axis command is specified in the incremental (G91) mode, the
vector is calculated using the coordinates which do not reflect the
amount of manual intervention.
Example)
N1 G90 G00 C10.0 ;
N2 G54.2 P1 ;
After executing the program, perform manual intervation with the
manual absolute swith is set to on. Then, movement of +20.0 about
the C-axis.
Afer restart
N3 G91 C30.0 ;
is specified, the coordinate value of C-axis is 60.0 in the workpiece
coordinate system.
In the fixture offset calculation, however, the coordinate value of
C-axis is considered as 40.0.