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6. INTERPOLATION FUNCTION
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In the polygonal turning with two spindles, the first spindle is used as a
workpiece rotation axis (master axis). The second spindle is used as a tool
rotation axis (polygon synchronization axis). Spindle rotation control is
applied to both spindles with a constant ratio.
The polygonal turning with two spindles can use different spindle speeds
for the same workpiece, because it performs automatic phase compensa-
tion when a polygon synchronization mode command is issued or the S
command is changed during polygon synchronization mode. With this
function, it is also possible to specify the phase difference between the
master and polygon synchronization axes.
Moreover, polygonal turning works with the first and second spindles on
each tool post in a two--path lathe application. However, polygonal
turning does not work with spindles on different tool posts.
The CNC command format for polygonal turning with two spindles is
described below. For the CNC command format for polygonal turning
(see Section 6.10.1), refer to the operator’s manual (for lathe). The two
formats are almost identical. The differences are in that the polygonal
turning with two spindles can specify a phase command (R) and re--issue
commands.
z G51.2 P_Q_R_;
This command starts the polygon synchronization mode or changes the
values specified for the polygon synchronization mode.
P: Master axis (first spindle) rotation ratio
Range of command value: Integer 1 to 999
(The direction in which the master axis rotates depends on the
commands (such as M03 and M04) issued under ordinary spindle
control.)
Q: Polygon synchronization axis (second spindle) rotation ratio
Range of command value: Integers 1 to 999 and --1 to --999
(The direction in which the polygon synchronization axis rotates
depends on the algebraic sign of the Q value, except when bit 1
(GDRC) of parameter No. 7603 = 1, in which case the polygon
synchronization axis rotates in the same direction as the first spindle.
In this case, Q cannot take a negative value.)
R: Relative phase difference between the master and polygon
synchronization axes
The range of command value and the increment system are the same
as for the rotation axis. However, the angle to rotate through is in
360/4096 degrees units.
(R is omissible. If it is not specified at all, the phase difference is
assumed to be 0. If bit 5 (PCOF) of parameter No. 7602 = 1 to disable
phase control, the R command is ignored, but no alarm condition is
assumed.)
6.10.2
Polygonal Turning with
Two Spindles
General
D Command format
D Mode command and
command value change