
TITLE
FANUC Series 16i/18i/21i-TB
AI nano contour control
Specifications
EDIT. DATE DESIG. DESCRIPTION
FANUC LTD
SHEET
10/37
DRAW. NO.
A-78962EN (2) is added. 2003.03.27 02
CUST.
2.8 Feedrate clamping by arc radius
The maximum allowable feedrate v for an arc of radius r specified in a program is calculated using the arc
radius R (parameter No.1731) and maximum allowable feedrate V (parameter No.1730) for the radius as
follows so that the acceleration in an arc block does not exceed the allowable value. If the specified
feedrate exceeds the feedrate v, the feedrate is automatically clamped to the feedrate v.
Maximum allowable acceleration =
V
R
2
R : Arc radius V : Feedrate for arc radius R
then, the maximum allowable feedrate v for an arc of radius r can be obtained using the following
expression:
v =
r
R
× V
(Note) As the specified arc radius becomes smaller, the maximum allowable feedrate v becomes lower. If
the maximum allowable feedrate v is lower than the setting of parameter No. 1732 (lower feedrate
limit for feedrate clamping by arc radius), it can be assumed to be the setting of the parameter to
prevent the maximum allowable feedrate from becoming too low.