Feedforward Control And Jerk Limitation - Ffwon, Soft - Siemens SINUMERIK 828D Manual

Important functions for 3- to 5-axis machining
3.7.3 Feedforward control and jerk limitation – FFWON,
SOFT, ...
Feedforward control and jerk limitation are called in CUST_832 on a combined basis. This is
because this combination offers ideal conditions for free-form surface milling. These functions
are set by the machine manufacturer.
Explanation of the commands
FFWON
(recommended)
FFWOF
BRISK
(not recommended)
SOFT
(recommended)
Jerk limitation function
Velocity profile
BRISK SOFT
V
time-optimized spares the mechanical parts
Acceleration profile
a
© Siemens AG All rights reserved SINUMERIK, Manual, Mold-Making with 3- to 5-Axis Simultaneous Milling
Feedforward control "on"
Feedforward control "off"
Without jerk limitation
Path axes accelerate abruptly
With jerk limitation
Jerk-limited acceleration of the path axes
Axial jerk limitation
To make acceleration as smooth on the
machine as possible, the acceleration profile
of the axes can be influenced using the
commands 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
t
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..
t
.
SOFT:
Acceleration behavior: Jerk-limited
acceleration 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.
3.7
115