
B-63783EN-1/01 6.NTERPOLATION FUNCTION
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6.11 CYLINDRICAL INTERPOLATION
General
An amount of travel around a rotation axis specified as an angle is
internally converted into an amount of travel along a linear axis on the
circumference, and linear interpolation or circular interpolation is
performed accordingly on another axis. After the interpolation, the
distance is converted back into an amount of travel around a rotation
axis.
The cylindrical interpolation function allows a movement on a curved
surface of a cylinder to be programmed in an expanded view. With this
function, a program for grooving a cylindrical cam can be created
easily.
- Plane selection (G17, G18, G19)
Whether the rotation axis corresponds to the X-axis, Y-axis, Z-axis, or
an axis parallel to one of the three axes is set in Parameter 1022. A G
code for selecting a plane must be specified, assuming that the rotation
axis is a specified linear axis.
For example, if the rotation axis is an axis parallel to the X-axis, G17
selects a plane determined by this axis and the Y-axis or an axis parallel
to the Y-axis (Xp-Yp plane).
Only a single rotation axis can be set for cylindrical interpolation.
- Feedrate
A feedrate specified in cylindrical interpolation mode is a speed on the
expanded side surface of the cylinder.
- Circular interpolation (G02, G03)
In cylindrical interpolation mode, circular interpolation using the
rotation axis and another linear axis can be performed. This
interpolation can be programmed using the same format as the circular
interpolation in which radius R is specified, as in 6.3. The radius value,
however, is specified in millimeters (metric input) or inches (inch
input), not as an angle.
Example) Circular interpolation on the Z-axis and C-axis
Set the fifth axis (axis parallel to the X-axis) as the C-axis in
parameter 1022.
Then, circular interpolation can be programmed as follows:
G18 Z_ C_;
G02(G03) Z_ C_ R_;
The sixth axis (axis parallel to the Y-axis) may also be set as the
C-axis in parameter 1022.
Then, circular interpolation is programmed as follows:
G19 C_ Z_;
G02(G03) Z_ C_ R_;