
PROGRAMMING
B–63534EN/02
20. AXIS CONTROL FUNCTIONS
579
G81 T_(L_)(Q_P_);
T : Number of teeth (range of valid settings: 1 to 1000)
L : Number of hob threads (range of valid settings: –21 to +21,
excluding 0)
The sign of L determines the direction of rotation
for the workpiece axis.
When L is positive, the direction of rotation for the workpiece
axis is positive (+ direction).
When L is negative, the direction of rotation for the workpiece
axis is negative (– direction).
When L is not specified, the number of hob threads is regarded
as being 1.
Q : Module or diametral pitch
In metric input, specify a module
(unit : 0.00001 mm, range of valid settings : 0.1 to 25.0 mm).
In inch input, specify a diametral pitch
(unit : 0.00001 [1/inch], range of valid settings: 0.1 to 254.0 [1/inch])
P : Twisted angle of a gear
(unit : 0.00001 degrees, range of valid settings : –90.0 to 90.0
degrees)
Specify P and Q to use helical gear compensation. In this case, if only one
of P and Q is specified, an alarm (P/S 181) is generated.
The decimal point can be specified in Q and P.
When a G81 command is issued to change to synchronization mode, the
EGB mode confirmation signal for the workpiece axis becomes “1” and
synchronization starts between the spindle and the workpiece axis.
During synchronization, control is performed such that the ratio of the
spindle speed to the workpiece–axis speed is the same as that of T
(number of teeth) to L (number of hob threads).
When a G81 command is again specified during synchronization without
canceling synchronization, an alarm (P/S 181) is generated.
(2)Synchronization end
When the following command is specified, sysnchronization is
cancelled.
G80;
Synchronization of all synchronized axes is canceled.
When a synchronization cancellation command is issued, the absolute
coordinates for the slave axis are updated according to the amount of
travel during synchronization.
For a rotation axis, the value obtained by rounding off the amount of
travel during synchronization to the nearest 360 degrees is added to the
absolute coordinates.
In a G80 block, do not specify addresses other than O or N.
(3)Helical gear compensation
For a helical gear, the workpiece axis is subjected to compensation for
movement along the Z axis (axial feed axis) according to the twisted
angle of the gear.
Helical gear compensation is performed with the following data.
Compensation angle
+
Z sin(P)
p T Q
360
(In metric input)