
PROGRAMMING20. AXIS CONTROL FUNCTIONS
B–63014EN/02
498
Gears can be cut by turning the workpiece (C–axis) in sync with the
rotation of the spindle (hob axis) connected to a hob.
Also, a helical gear can be cut by turning the workpiece (C–axis) in sync
with the motion of the Z–axis (axial feed axis).
Spindle
C–axis
Gear material
Hob
Helical gear
G81 T_ L_ Q_ P_ ;
T : Number of teeth (Specifiable range: 1 to 5000)
L : Number of hob threads (Specifiable range: 1 to 20 with a sign)
⋅ The sign of L specifies the direction of rotation of the C–axis.
⋅ If L is positive, the C–axis rotates in the positive direction (+).
⋅ If L is negative, the C–axis rotates in the negative direction (–).
Q: Module or diametral pitch
For metric input, specify a module.
(Unit: 0.00001 mm, Specifiable range: 0.01 to 25.0 mm)
For inch input, specify a diametral pitch.
(Unit: 0.00001 inch
–1
, Specifiable range: 0.01 to 250.0 inch
–1
)
P : Gear helix angle
(Unit: 0.0001 deg, Specifiable range: –90.0 to +90.0 deg)
P and Q must be specified when a helical gear is to be cut.
G80; Cancels synchronization between the hob axis and C–axis.
The C–axis (workpiece) is usually the fourth axis. However, any axis can
be set as the C–axis by setting the corresponding parameter appropriately
(parameter No. 7710).
The synchronization status is maintained provided:
⋅ The interlock signal for the C–axis is turned on.
⋅ The feed hold state exists.
20.7
HOBBING MACHINE
FUNCTION (G80, G81)
Format
Explanations
D Setting the C–axis
D Maintaining the
synchronization status