
B-63944EN-2/02 PROGRAMMING 3.INTERPOLATION FUNCTION
- 21 -
Base circle
Start point
Involute curve
(X, Y)
End point
o
(Xo, Yo)
R
X
Y
Fig. 3.1 (b) Involute curve
Involute curves on the Z-X plane and Y-Z plane are defined in the
same way as an involute curve on the X-Y plane.
- Start point and end point
The end point of an involute curve is specified using address Xp, Yp,
or Zp. An absolute value or incremental value is used to specify an
Xp, Yp, or Zp value. When using an incremental value, specify the
coordinates of the end point viewed from the start point of the involute
curve.
When no end point is specified, alarm PS0241 is issued.
If the specified start point or end point lies within the base circle,
alarm PS0242 is issued. The same alarm is issued if cutter
compensation C causes the offset vector to enter the base circle. Be
particularly careful when applying an offset to the inside of an
involute curve.
- Base circle specification
The center of a base circle is specified with I, J, and K, corresponding
to X, Y, and Z. The value following I, J, or K is a vector component
defined when the center of the base circle is viewed from the start
point of the involute curve; this value must always be specified as an
incremental value, regardless of the G90/G91 setting. Assign a sign
to I, J, and K according to the direction.
If I, J, and K are all left unspecified, or I0, J0, K0 is specified, alarm
PS0241 or PS0242 is issued.
If R is not specified, or R ≤ 0, alarm PS0241 or PS0242 is issued.