4. INTERPOLATION FUNCTIONS
The amount of travel of a rotary axis specified by an angle is once
internally converted to a distance of a linear axis along the outer surface
so that linear interpolation or circular interpolation can be performed with
another axis. After interpolation, such a distance is converted back to the
amount of travel of the rotary axis.
The cylindrical interpolation function allows the side of a cylinder to be
developed for programming. So programs such as a program for
cylindrical cam grooving can be created very easily.
G07.1 IP r ; Starts the cylindrical interpolation mode
(enables cylindrical interpolation).
G07.1 IP 0 ; The cylindrical interpolation mode is cancelled.
IP : An address for the rotation axis
r : The radius of the cylinder
Specify G07.1 IP r ; and G07.1 IP 0; in separate blocks.
G107 can be used instead of G07.1.
Use parameter (No. 1022) to specify whether the rotation axis is the X–,
Y–, or Z–axis, or an axis parallel to one of these axes. Specify the G code
to select a plane for which the rotation axis is the specified linear axis.
For example, when the rotation axis is an axis parallel to the X–axis, G17
must specify an Xp–Yp plane, which is a plane defined by the rotation axis
and the Y–axis or an axis parallel to the Y–axis.
Only one rotation axis can be set for cylindrical interpolation.
A feedrate specified in the cylindrical interpolation mode is a speed on the
developed cylindrical surface.
In the cylindrical interpolation mode, circular interpolation is possible
with the rotation axis and another linear axis. Radius R is used in
commands in the same way as described in II–4.4.
The unit for a radius is not degrees but millimeters (for metric input) or
inches (for inch input).
< Example Circular interpolation between the Z axis and C axis >
For the C axis of parameter (No.1022), 5 (axis parallel with the X axis)
is to be set. In this case, the command for circular interpolation is
G02 (G03) Z__C__R__;
For the C axis of parameter (No.1022), 6 (axis parallel with the Y axis)
may be specified instead. In this case, however, the command for
circular interpolation is
G02 (G03) Z__C__R__;
D Plane selection
(G17, G18, G19)
D Circular interpolation