HEIDENHAIN TNC 426B (280 472) Touch Probe Cycles - Manual (Page 143)

HEIDENHAIN TNC 426, TNC 430 131
5.3 T
y
pes of Digitizing
Contour line digitizing
n Triggering touch probe: Digitizing Cycle 7 CONTOUR LINES
n Measuring touch probe: Digitizing cycle 17 CONTOUR LINES
The CONTOUR LINES cycle scans a 3-D contour by circling around the
model in a series of upwardly successive levels. This cycle is
particularly useful for digitizing steep contours, such as the gating of
injection molding dies, or for digitizing a single contour line, such as
the contour of a cam disk.
After first making contact with the form, the probe starts scanning at
constant height around the form. After it has orbited the form and
returned to the first probe point, it then moves in the positive or
negative direction of the probe axis by the value of the LINE SPACING.
It then once again orbits the form at constant height. This process is
repeated until the entire range has been scanned.
Once the entire range has been scanned, the touch probe returns to
the clearance height and the programmed starting point.
When you are digitizing with the measuring touch probe, the TNC
stores positions at which sharp changes in direction have occurred. Up
to 1000 positions per line can be stored. In the next line, the TNC
automatically reduces the probe feed rate in the vicinity of such
positions. This behavior improves the scanning results.
Requirements for the scanning range
n
In the touch probe axis: The defined RANGE must be lower than the
highest point of the 3-D model by at least the radius of the probe tip.
n In the plane perpendicular to the touch probe: The defined RANGE
must be larger than the 3-D model by at least the radius of the probe
tip.
Starting position
n Probe axis coordinate of the MIN point from Cycle 5 RANGE if the
line spacing is entered as a positive value.
n
Probe axis coordinate of the MAX point from Cycle 5 RANGE if the
line spacing is entered as a negative value.
n
Define the working plane coordinates in the CONTOUR LINES
cycle.
n Automatically move to the starting position: First in the probe axis to
clearance height, then in the working plane.
X
Z
Y
Before the CONTOUR LINES cycle, the part program must
have a range defined in the RANGE cycle.
Digitizing cycle 17 cannot be combined with digitizing
cycle 15.