
B–63522EN/02
3. INTERPOLATION FUNCTIONS
NC FUNCTION
69
Specifying an intermediate and end point on an arc enables circular
interpolation in a 3–dimensional space.
The command format is as follows:
G02.4 X
X1
Y
Y1
Z
Z1
α
α1
β
β1
; First block (mid–point of the arc)
X
X1
Y
Y1
Z
Z1
α
α1
β
β1
; Second block (end point of the arc)
α,β : Arbitrary axes other than the 3–dimensional circular inter-
polation axis (up to two axes)
Instead of G02.4, G03.4 can also be used. There is no difference in
movement between these commands.
An arc in a 3–dimensional space is uniquely defined with its start point
(current position) and a specified intermediate point and end point, as
shown below. Two command blocks are used to define this arc. The first
command block specifies the tool path between the start point and
intermediate point. The second command block specifies the tool path
between the intermediate point and end point.
X
Y
Z
Start point
Mid–point
(X1,Y1,Z1)
End point
(X2,Y2,Z2)
Fig. 3.16 Start, Mid, and End Points
3.16
3–DIMENSIONAL
CIRCULAR
INTERPOLATION
(G02.4 AND G03.4)
Format
D Start point, mid–point,
and end point