Siemens SINUMERIK 828D Manual page 87

Important functions for 3- to 5-axis machining
Direction vector (A3=<value> B3=<value> C3=<value>)
The components of a vector in space are programmed during the programming of direction
vectors. Whereby A3 is associated with the X component, B3 is associated with the Y component
and C3 is associated with the Z component; the length of the vector is of no significance. For
example, A3=1 B3=1 C3=1 defines a vector with the components (1,1,1) which points in the
direction of the spatial diagonal of the coordinate system.
Programming direction
vector
The vectors clearly correspond to the I, J, K vectors used in CAM systems. However, as I, J, K
are reserved for the circle parameters in the CNC standard, the addresses A3, B3 and C3 are
used for the vector components in SINUMERIK.
The use of the direction vector is recommended. The accuracy level selected should be as
high as possible. As far as 5-axis programs are concerned, practical experience has
shown that good results can be achieved by using 5 decimal places for linear axes and
6 decimal places for the direction vector.
© Siemens AG All rights reserved SINUMERIK, Manual, Mold-Making with 3- to 5-Axis Simultaneous Milling
C3
B3
A3
The components of the direction vector are
programmed with A3, B3, and C3. The vector
points towards the tool adapter; the length of
the vector is of no significance. Vector
components that have not been programmed
are set equal to zero.
N020 TRAORI
N035 G54
N040 G1 X0 Y0 Z0 A3=1 B3=1 C3=1 F10000
...
The example shows the tool tip in the position
(0,0,0), and the tool shank is the diagonal of a
cube (35.26° in relation to X-Y plane).
3.5
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