Siemens SINUMERIK 840D

Key functions for 5-axis machining
3.6
© Siemens AG All rights reserved. SINUMERIK, Manual, 5-axis machining
70
3.6.3 Feedforward control and jerk limitation – FFWON,
SOFT, ...
Feedforward control and jerk limitation can only be called in CYCLE832 on a combined basis.
This is because this combination offers ideal conditions for free-form surface milling. Of course,
both of these functions can also be programmed separately.
Explanation of the commands
Jerk limitation function
FFWON Feedforward control "on"
FFWOF Feedforward control "off"
BRISK Without jerk limitation
Path axes accelerate abruptly
SOFT With jerk limitation
Jerk-limited acceleration of the path axes
Axial jerk limitation (maximum jerk in the machine data
JOG_AND_POS_MAX_JERK (jog and positioning)
and MAX_AX_JERK (continuous-path mode)
.
. To make acceleration as gentle on the
machine as possible, the acceleration profile
of the axes can be influenced using the com-
mands Soft and Brisk. If Soft is activated, the
acceleration behavior does not change
abruptly but is increased in the form of a linear
characteristic. This helps to protect the
machine and improves the surface quality of
workpieces, as much less machine resonance
is generated.
BRISK:
Acceleration behavior: Path axes accelerate
abruptly in accordance with the set machine
data.
The axis slides accelerate at the maximum
rate until the feedrate is achieved. BRISK
enables time-optimized machining, but with
jumps in the acceleration curve..
. . SOFT:
Acceleration behavior: Jerk-limited accelera-
tion of the path axes.
The axis slides accelerate at a constant rate
until the feedrate is achieved. As a result of
the jerk-free acceleration characteristic, SOFT
permits a higher path accuracy and less stress
on the machine.
Time-optimized
BRISK
Protecting the
mechanical parts
Acceleration profile
SOFT
Speed profile
t
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V
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