Ncu Link With Different Interpolation Cycles; 2.15.10.1 Example Of Eccentric Turning - Siemens SINUMERIK 840D sl Function Manual

Several Operator Panels on Several NCUs, Distributed Systems (B3)
Examples
2.15.10

NCU link with different interpolation cycles

2.15.10.1 Example of eccentric turning

Task assignment
Create a non-circular shape with the following characteristics:
Ellipticity: 0.2 mm
Base circle diameter: 50 mm
Z path per revolution: 0.1 mm
Spindle speed: 3000 rpm
A sinusoidal approximation via a cubic polynomial per 45 degrees of spindle revolution
should be sufficient for the required precision.
Note
Polynomials up to the 5th degree can be used. See Programming Manual Advanced.
The part program of which excerpts are shown runs in a channel of the NCU with the faster
interpolation cycle where the X axis is configured as local axis and the C and Z axes as link
axes.
CAD systems which calculate coefficients based on contour points and the required degree
of the polynomial are used for defining the polynomial coefficients.
The following part program describes the commands required for the first spindle revolution.
It must then be continued accordingly for the entire required length of the Z path:
G0 C0 X24.95 Z0 ; Start position
FGROUP(C) ; Ensures constant spindle speed
G1 G642 F1080000 ; Spindle speed 3000 rpm
POLY ;Specification of polynomials
C=DC(45.0000000) PO[X]=(25.0,.0750000,-0.0250000)
PO[Z]=(.2125000,0,0)
;1/8 circle, lineare Z movement, 1/4 sine in X
C=DC(90.0000000) PO[X]=(25.0500000,0,-0.0250000)
PO[Z]=(.2250000,0,0)
C=DC(135.0000000) PO[X]=(25.0,-0.0750000,.0250000)
PO[Z]=(.2375000,0,0)
C=DC(180.0000000) PO[X]=(24.9500000,0,.0250000) PO[Z]=(.2500000,0,0)
C=DC(225.0000000) PO[X]=(25.0,.0750000,-0.0250000)
PO[Z]=(.2625000,0,0)
C=DC(270.0000000) PO[X]=(25.0500000,0,-0.0250000)
PO[Z]=(.2750000,0,0)
C=DC(315.0000000) PO[X]=(25.0,-0.0750000,.0250000)
PO[Z]=(.2875000,0,0)
C=DC(0) PO[X]=(24.9500000,0,.0250000) PO[Z]=(.3000000,0,0)
...
Machine data
Please refer to "Configuration of link axes", "Axis container" for notes on the configuration of
machine data.
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Function Manual, 03/2009, 6FC5397-1BP10-4BA0
Extended Functions