Sag Compensation And Angularity Error Compensation - Siemens SINUMERIK 802D sl Function Manual

Compensation (K3)
11.3 Interpolatory compensation
11.3.3

Sag compensation and angularity error compensation

Note
This function is under license and is not available with version T/M value.
If the corresponding option is activated without a valid license, alarm 8081 "%1 option(s) that
has (have) not been licensed using a license key was (were) set" is output. It will not be
possible to operate the machine as normal.
For information on operations relating to "Setting (an) option(s)", please refer to the section
titled "Licensing in SINUMERIK 802D sl" in the "Turning, Milling, Grinding, Nibbling"
Operating Instructions.
Prerequisites
The sag compensation and angularity error compensation functions cannot be applied for
PLC axes.
Function
Unlike for LEC, the basic and compensation axes do not need to be identical for "Sag
compensation" or "Angularity error compensation", which is why an axis assignment is
required in every compensation table.
In order to compensate for sag of one axis (base axis) which results from its own weight, the
absolute position of another axis (compensation axis) must be influenced. "Sag
compensation" is therefore an inter-axis compensation.
As illustrated in the diagram below, the further the machining head moves in the negative Y1
axis direction, the more the cross-arm sags in the negative Z1 axis direction.
The error must be recorded in the form of a compensation table that contains a
compensation value for the Z1 axis for every actual value position in the Y1 axis. It is
sufficient to enter the compensation values for the interpolation points.
When the Y1 axis traverses, the control calculates the corresponding compensation value in
the Z1 axis in interpolation cycles performing linear interpolation for positions between the
interpolation points. This compensation is sent to the position control loop as an additional
setpoint. A positive compensation value causes the corresponding machine axis to move in
the negative direction.
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Turning, Milling, Nibbling
Function Manual, 11/2012, 6FC5397-1CP10-5BA0