# FANUC Series 16/18/160/180-Model C Machining Center Operators Manual

PROGRAMMING
4. INTERPOLATION FUNCTIONS
B–62764EN/01
66
k
θ
tan (I)
tan (B)
Z (θ) = { –Utan (I) }(e –1) +Z (0) (3)
2
r
X (θ) = { –Utan (I) }(e –1) (4)
2
r
k
θ
tan (I)
1
A () = (–1)
360
2π
θ
K =
tan (I)
tan (J)
X (), Z (), A (): Absolute value on the X–axis, Z–axis, and
A–axis from the origin
r : Left end diameter
U : Excess length
I : Taper angle
B : Groove bottom taper angle
J : Helix angle
X : Amount of movement on the linear axis
: Helix direction (0: Positive, 1: Negative)
: Workpiece rotation angle
From expressions (3) and (4), the following is obtained ;
Z () = tan (B) X () + Z (0) (5)
The groove bottom taper angle (B) is determined from the end
point position on the X–axis and Z–axis according to Expression
5. The amount of movement on the Z–axis is determined from a
groove bottom taper angle (B) and X–axis position.
From Expressions (1) and (4), the following is determined:
R = r/2 – Utan (I) (6)
Constant R is determined from the left end diameter (r) and excess
length (U) according to Expression (6). Specify a taper angle (I) in
address I, and specify a helix angle (J) in address J. Note, howev-
er, that a negative value must be specified as the taper angle (I) for
constant helix machining in order to produce a reverse tapered fig-
ure. Select a helix direction with G02.3 or G03.3. The user can
perform constant helix machining to produce a tapered figure or a
reverse tapered figure.
Relational expressions
where
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