HEIDENHAIN TNC 640, User Manual, Page: 536 / 948

Special Functions | Adaptive Feed Control AFC (option 45)
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HEIDENHAIN | TNC 640 | Conversational Programming User's Manual | 10/2017
12.5 Adaptive Feed Control AFC (option 45)
Application
This feature must be enabled and adapted by the
machine tool builder.
Your machine tool builder may also specify whether
the spindle power or any other value is used as input
quantity by the control.
If you have enabled the software option for turning
(Option 50), you can use AFC in turning mode as well.
Adaptive feed control is not intended for tools
with diameters less than 5 mm. If the rated power
consumption of the spindle is very high, the limit
diameter of the tool may be larger.
Do not work with adaptive feed control in operations in
which the feed rate and spindle speed must be adapted
to each other, such as tapping.
In adaptive feed control the control automatically controls the feed
rate during program run as a function of the current spindle power
consumption. The spindle power required for each machining step
is to be recorded in a teach-in cut and saved by the control in a file
belonging to the machining program. At the start of each machining
step, usually when the spindle is switched on, the control controls
the feed rate so that it remains within the limits that you have
defined.
If the cutting conditions do not change, you can define
the spindle power consumption, which has been
determined in a teach-in cut, as permanent tool-
dependent reference power. Use the
AFC-LOAD
column
in the tool table to do this. If you enter a value manually
in this column, the control does not execute any more
teach-in cuts.
This makes it possible to avoid negative effects on the tool, the
workpiece, and the machine that might be caused by changing
cutting conditions. Cutting conditions are changed particularly by:
Tool wear
Fluctuating cutting depths that occur especially with cast parts
Fluctuating hardness caused by material flaws