Compressor (Compcad, Compsurf) - Siemens SINUMERIK 828D Manual

3.7
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Important functions for 3- to 5-axis machining

3.7.1 Compressor (COMPCAD, COMPSURF)

The compressor is called in CYCLE832. If it is to be programmed separately, then proceed as
described below. The common objective of compressor functions is to optimize the surface
quality and machining velocity by achieving continuous block transitions and increasing the path
length for each block. You can use machine data to set whether only G1 blocks or G2/G3 or G0
blocks should also be compressed.
Explanation of the commands
COMPOF
COMPCAD
(default for
Advanced Surface)
COMPCURV
(do not use anymore)
COMPSURF
(default for
Top Surface)
Operating principle of the compressor
1 2
© Siemens AG All rights reserved SINUMERIK, Manual, Mold-Making with 3- to 5-Axis Simultaneous Milling
Compressor off
Compressor on - surface quality and velocity are further
optimized.
COMPCAD smooths the points along the characteristic before
approximation
(B spline) and offers, at a high path velocity, the highest degree of
accuracy with transitions that have a constant acceleration rate.
Preferably used to mill free-form surfaces (recommended).
Compressor on.
Blocks are approached using a polynomial. Block transitions are
jerk-free. Preferably used for circumferential milling.
Compressor on.
The COMPSURF compressor ensures a significantly improved
workpiece surface for inclined line-by-line finishing programs,
poor data quality - or for example, irregular point distribution in NC
programs from the CAD/CAM system. Further, COMPSURF
improves complying with acceleration and jerk limits. As a
consequence, machine-specific dynamic parameters can be
increased.
In accordance with the specified tolerance
3
band, the compressor
of motion commands
compresses them into a spline
be directly executed by the control. A new
contour is created whose characteristic lies
within the specified tolerance range.
The compressor generates smooth paths and
paths with constant curvature. The constant
curvature results in a steady velocity and
acceleration characteristic, meaning that the
machine can run at higher velocities, thereby
increasing productivity.
takes a sequence
1
combines them and
2
, which can
3