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

Feedrate Control and Spindle Motion

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

7.9 Feedrate optimization for curved path sections (CFTCP, CFC, CFIN)
Function
The programmed feedrate initially refers to the cutter center path when the G41/G42
override is activated for the cutter radius (cf. chapter "Frames").
When you mill a circle – the same applies to polynomial and spline interpolation – the extent
of the change in feedrate at the cutter edge is such that it can have a considerable effect on
the quality of the machined part.
Example: you are milling a small external radius with a large tool. The path that the outside
of the cutter needs to cover is much longer than the path along the contour.
You therefore work with a very small feedrate on the contour. In order to avoid effects like
this, you should regulate the feedrate for curved contours accordingly.
Programming
CFTCP Constant feedrate on cutter center-point path, deactivate feedrate override
Or
CFC Constant feedrate only on contour
Or
CFIN Constant feedrate only on inside radii, no increment at outer radii
300
Programming Manual, 11/2006, 6FC5398-1BP10-2BA0
Fundamentals