Corners For Face Milling - Siemens SINUMERIK 840D sl Function Manual

W5: 3D tool radius compensation
19.3 Face milling
19.3.4

Corners for face milling

Two surfaces which do not merge tangentially form an edge. The paths defined on the
surfaces make a corner. This corner is a point on the edge.
The corner type (inside or outside corner) is determined by the surface normal of the surfaces
involved and by the paths defined on them.
The surface normals of the two surfaces forming the edge may point in opposite directions of
the overall surface (the front edge of one surface is continued on the rear edge of the second
surface), see also the following Figure. Such transitions are not permissible and are rejected
with an alarm.
The scalar product of the surface normal vector and (possibly variable) tool orientation on one
corner/path must be positive at each point, i.e. it is not permissible to machine from the rear
face of the surface. Failure to observe this rule results in an alarm. The permissible ranges of
validity of tool orientation for inside and outside corners are illustrated in the following Figure.
These ranges are further restricted by the condition that the angle between the surfaces to be
machined and the "steepest" surface line of the tool surface must not be lower than a
particular machine data setting. The "steepest" surface line is a line at angle a to the tool
longitudinal axis (this line is in the same direction as the tool longitudinal axis on cylindrical
tools). This restriction must be imposed to ensure that the contact point on the tool does not
leave the permissible range.
Figure 19-16 Corners for face milling
It is possible to insert blocks that contain no motion commands (e.g. auxiliary function
outputs) and/or that include motions of axes not involved in the path between two blocks
which contain a path definition. Changes in orientation can also be programmed in such
intermediate blocks. The only exception applies to the activation and deactivation of the 3D
tool radius compensation function, i.e. intermediate blocks with changes in orientation may
not be inserted between the activation block and the first corrected block or between the last
corrected block and the deactivation block. Other intermediate blocks are, however,
permitted.
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Function Manual, 09/2011, 6FC5397-2BP40-2BA0
Special Functions