
3.INTERPOLATION FUNCTION PROGRAMMING B-63944EN-2/02
- 22 -
- Choosing from two types of involute curves
When only a start point and I, J, and K data are given, two types of
involute curves can be created. One type of involute curve extends
towards the base circle, and the other extends away from the base
circle. When the specified end point is closer to the center of the
base circle than the start point, the involute curve extends toward the
base circle. In the opposite case, the involute curve extends away
from the base circle.
- Feedrate
The cutting feedrate specified in an F code is used as the feedrate for
involute interpolation. The feedrate along the involute curve
(feedrate along the tangent to the involute curve) is controlled to
satisfy the specified feedrate.
- Plane selection
As with circular interpolation, the plane to which to apply involute
interpolation can be selected using G17, G18, and G19.
- Cutter compensation
Cutter compensation can be applied to involute curve machining. As
with linear and circular interpolation, G40, G41, and G42 are used to
specify cutter compensation.
G40: Cutter compensation cancel
G41: Cutter compensation left
G42: Cutter compensation right
First, a point of intersection with a segment or an arc is approximated
both at the start point and at the end point of the involute curve. An
involute curve passing the two approximated points of intersection
with the start point and end pint becomes the tool center path.
Before selecting the involute interpolation mode, specify G41 or G42,
cancel involute interpolation, and then specify G40. G41, G42, and
G40 for cutter compensation cannot be specified in the involute
interpolation mode.
- Automatic speed control
Cutting precision can be improved by automatically overriding the
programmed feedrate during involute interpolation. See a
subsequent subsection, "Automatic Speed Control for Involute
Interpolation."