Siemens SINUMERIK 828D Function Manual page 1367

Feedrate for internal radius and external radius path sections
For circular blocks or spline blocks with curvature in the same direction and tool radius offset activated (G41/
G42), the programmed feedrate can act on the center point path or on the contour (depending on the internal
radius or external radius path sections).
A group of G commands is provided for this purpose:
•
CFTCP
Programmed feedrate acting on the center point path.
•
CFC
Programmed feedrate acting on the contour.
•
CFCIN
Programmed feedrate acting only on the contour with a concave spline.
References:
Programming Manual, Fundamentals
Maximum tool path velocity
The maximum path velocity results from the maximum velocities of the linear or rotary axes involved (MD32000
$MA_MAX_AX_VELO), i.e. the axis with the lowest maximum velocity determines the maximum path velocity.
This cannot be exceeded.
If G0 is programmed, traversing is at the path velocity resulting from the MD32000 $MA_MAX_AX_VELO
limitation.
Limit velocity for path axes
In addition, the FL[<axis>] command can be used to program a limit velocity for path axes (geometry and
synchronized axes).
This enables separate feedrates to be programmed for the working plane and infeed axis. This means that a
feedrate is specified for both path­related interpolation and for the infeed axis. The axis perpendicular to the
selected machining plane is designated as the infeed axis. The infeed axis­specific feedrate can be programmed
to limit the axis velocity and therefore the path velocity. No coordinate rotations through frames should be
included, i.e., the infeed axis must be an axis of the standard coordinate system. This function can be used to
compensate for the fact that a cutter has a lower cutting performance on the face side than across the cutter
circumference.
Programming example:
Program code
... G94...
X30 Y20 F200
FL[Z]=50 Z-30
Basic Functions
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
Comment
; Selection of feedrate type (mm/min)
; Path feedrate = 200 mm/s
; Max. feedrate for Z axis: 50 mm/s
V1: Feedrates
17.2 Path feedrate F
1367