
B–63503EN–1/01
6. INTERPOLATION FUNCTION
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Polygonal turning uses the position coder feedback signal to control the
positional relationship (cutting position) between the spindle and tool
rotation axis, and the ratio of speed.
Parameter No. 7610 specifies the controlled axis (servo axis) to be used
as the tool rotation axis.
The same parameter setting as for ordinary servo axes applies to the servo
axis connection for polygonal turning except for some parameters.
When the machine is not in the polygonal turning mode, the servo axis
specified as the rotation tool axis functions as a feed axis. So, the servo
axis can be:
· Used as a subspindle under PMC axis control
· Positioned by a move command from a machining program.
However, be careful about the angle to rotate through and feedrate. Read
the operator’s manual (for lathe) and the following examples.
· The following descriptions exemplify typical parameter setting for
polygonal turning using a serial pulse coder (with a million pulse
capability).
→ The parameter setting described here is not a must for polygonal
turning.
→ Specify typical values for parameters unless otherwise stated.
D Tool rotation axis setting
This example uses the CNC’s fourth axis (connected as the Y–axis) as
a rotation tool axis for polygonal turning.
Parameter No. 7610 = 4
(controlled axis number for the tool rotation axis)
The following description assumes that the axis type parameter is set
to the fourth axis.
D Servo parameter setting
Set the servo parameters as listed below:
CMR = 1
DMR = 36/1000
(With the above setting, the reference counter capacity is 36000.)
Parameter No. 1820 = 2 (CMR)
Parameter No. 1821 = 36000 (reference counter capacity)
Parameter No. 2084 = 36 (DMR numerator)
Parameter No. 2085 = 1000 (DMR denominator)
For the other servo parameters, specify typical values.
D Parameter setting for polygonal turning
The least command increment, detection unit, the angle to rotate
through per rotation for the polygon axis are as follows:
Least command increment =
L CMR
Q DMR
Detection unit =
DMR
least command increment
=
L
Q DMR
Angle to rotate through per tool axis rotation
=
360
least command increment
D Tool rotation axis
(servo axis) connection
D Examples of parameter
setting