HEIDENHAIN TNC 426B (280 472) ISO programming - Manual (Page 321)

12 3-D Touch Probes 306
Setting datums using holes
(not TNC 410)
A second soft-key row provides soft keys for using holes or
cylindrical studs to set datums.
Define whether a hole or stud is to be probed
ú Select the probing functions with the TOUCH PROBE
soft key, shift the soft-key row
ú Select the probing functions for holes: e.g., press the
PROBING ROT soft key.
ú Select holes or cylindrical studs: the selected element
appears in a box.
Probing holes
Pre-position the touch probe approximately in the center of the
hole. After you have pressed the external START key, the TNC
automatically probes four points on the wall of the hole.
Move the touch probe to the next hole and have the TNC repeat the
probing procedure until all the holes have been probed to set
datums.
Probing cylindrical studs
Position the ball tip at a starting position near the first touch point of
the stud. Select the probing direction by soft key and press the
machine START button to start probing. Perform the above
procedure four times.
Application Soft key
Basic rotation from 2 holes:
The TNC measures the angle between the line
connecting the centers of two holes and
a nominal position (angle reference axis).
Basic rotation from 4 holes:
The TNC calculates the intersection of the line
connecting the first two probed holes with the line
connecting the last two probed holes. You need to
probe diagonally opposite holes after one another
(as shown on the soft key), as otherwise the datum
calculated by the TNC will be incorrect
Circle center from 3 holes:
The TNC calculates a circle that intersects the
centers of all three holes, and finds the center.
12.2 Set
ting the D
at
um with a 3-D
Touc
h
Pr
obe
Okap12.pm6 29.06.2006, 08:06 306