
PAGE
4/21
FANUC Series 16
i
/18
i
–TA/TB
HOBBING FUNCTION
EDT. DATE DESIG. DESCRIPTION
A – 78600E
NO.
TITLE
01 2001.09.17 Newly
Helical Gear Compensation
When a helical gear is to be cut, compensation for the C-axis, according to
the amount of travel along the Z-axis (second axis) (axial feed) and gear
helix angle, is required.
Helical gear compensation is performed by adding compensation pulses,
calculated using the following formula, to the C-axis which is
synchronized with the hob axis:
Compensation angle =
360
)sin(
×
×
××
R
PQZ
π
(For metric input)
Or
Compensation angle =
360
)sin(
×
××
×
QR
PZ
π
(For inch input)
where
Compensation angle : Signed absolute value (degree)
Z : Amount of travel along the Z-axis after the specification of G81.4
(mm or inches)
Total amount of travel along the Z-axis in both automatic and
manual modes
P : Signed gear helix angle (degree)
R : Number of teeth
Q : Module (mm) or diametral pitch (inch
-1
)
The values of P, R, and Q must be programmed.