Feedrate Optimization For Curved Path Sections (Cftcp, Cfc, Cfin) - Siemens SINUMERIK 840D sl Programming Manual

Program code
N20 POS[V]=100 FAD[V]=200
Traversing range:
The traversing range is limited by the starting position and the programmed end point.
2.7.9

Feedrate optimization for curved path sections (CFTCP, CFC, CFIN)

With activated correction mode G41/G42, the programmed feedrate for the milling tool radius
first refers to the milling tool center path (refer to Chapter "Coordinate transformations (frames)
(Page 305)").
When you mill a circle (the same applies to polynomial and spline interpolation) the extent to
which the feedrate varies at the cutter edge is so significant under certain circumstances that
it can impair the quality of the machined part.
Example: Milling a small outside radius with a large tool. The path that the outside of the milling
tool must travel is considerably longer than the path along the contour.
Because of this, machining at the contour takes place with a very low feedrate. To prevent
adverse effects, the feedrate needs to be controlled accordingly for curved contours.
Syntax
CFTCP
CFC
CFIN
NC programming
Programming Manual, 12/2019, 6FC5398-2EP40-0BA0
Description
; Axial target position = 100, axial feedrate = 200 mm/min
; and velocity override with handwheel.
; Acceleration from 100 to 200 mm/min in N20. The
; Handwheel can be used to vary the velocity depending on the direc-
tion of rotation
; between 0 and the maximum value (machine data).
Fundamentals
2.7 Feed control
131