Measure Hole (Cycle 421, Din/Iso: G421, Software Option 17); Cycle Run; Please Note While Programming - HEIDENHAIN TNC 620 User Manual

15.5 MEASURE HOLE (Cycle 421, DIN/ISO:
G421, software option 17)

Cycle run

Touch Probe Cycle 421 measures the center and diameter of a hole
(or circular pocket). If you define the corresponding tolerance values
in the cycle, the TNC makes a nominal-to-actual value comparison
and saves the deviation value in system parameters.
1 Following the positioning logic, the TNC positions the touch
probe at rapid traverse (value from FMAX column) (see
"Executing touch probe cycles", page 304) to touch point 1. The
TNC calculates the touch points from the data in the cycle and
the safety clearance from the SET_UP column of the touch
probe table.
2 Then the touch probe moves to the entered measuring height
and runs the first probing process at the probing feed rate
(column F). The TNC derives the probing direction automatically
from the programmed starting angle.
3 Then the touch probe moves in a circular arc either at measuring
height or at clearance height to the next starting point
probes the second touch point.
4 The TNC positions the probe to starting point
starting point 4 to probe the third and fourth touch points.
5 Finally the TNC returns the touch probe to the clearance height
and saves the actual values and the deviations in the following
Q parameters:
Parameter number
Q151
Q152
Q153
Q161
Q162
Q163

Please note while programming:

Before a cycle definition you must have programmed
a tool call to define the touch probe axis.
The smaller the angle, the less accurately the TNC
can calculate the hole dimensions. Minimum input
value: 5°
The parameters
on this cycle. You do not need to make any entries.
These parameters have only been integrated for
reasons of compatibility. If, for example, you import
a program of the contouring control for turning
and milling, TNC 640, you will not receive an error
message.
HEIDENHAIN | TNC 620 | User's manual for cycle programming | 9/2015
MEASURE HOLE (Cycle 421, DIN/ISO: G421) 15.5
3 and then to
Meaning
Actual value of center in reference axis
Actual value of center in minor axis
Actual value of diameter
Deviation at center of reference axis
Deviation at center of minor axis
Deviation from diameter
Q498 and Q531 have no impact
2 and
15
395