Cycle run – HEIDENHAIN TNC 640 (34059x-01) Cycle programming User Manual
Page 534

534
Touch Probe Cycles: Automatic Tool Measurement
20.3 Measur
ing the T
ool Length
(Cy
c
le 31 or 481, DIN/ISO:
G481)
20.3 Measuring the Tool Length
(Cycle 31 or 481, 
DIN/ISO: G481)
Cycle run
To measure the tool length, program the measuring cycle TCH PROBE 
31 or TCH PROBE 480 (see also "Differences between Cycles 31 to 33 
and Cycles 481 to 483" on page 529). Via input parameters you can 
measure the length of a tool by three methods:
If the tool diameter is larger than the diameter of the measuring 
surface of the TT, you measure the tool while it is rotating.
If the tool diameter is smaller than the diameter of the measuring 
surface of the TT, or if you are measuring the length of a drill or 
spherical cutter, you measure the tool while it is at standstill.
If the tool diameter is larger than the diameter of the measuring 
surface of the TT, you measure the individual teeth of the tool while 
it is at standstill.
Cycle for measuring a tool during rotation
The control determines the longest tooth of a rotating tool by 
positioning the tool to be measured at an offset to the center of the 
touch probe and then moving it toward the measuring surface of the 
TT until it contacts the surface. The offset is programmed in the tool 
table under Tool offset: Radius (TT: R_OFFS).
Cycle for measuring a tool during standstill (e.g. for drills)
The control positions the tool to be measured over the center of the 
measuring surface. It then moves the non-rotating tool toward the 
measuring surface of the TT until it touches the surface. To activate 
this function, enter zero for the tool offset: Radius (TT: R_OFFS) in the 
tool table.
Cycle for measuring individual teeth
The TNC pre-positions the tool to be measured to a position at the side 
of the touch probe head. The distance from the tip of the tool to the 
upper edge of the touch probe head is defined in offsetToolAxis. You 
can enter an additional offset with tool offset: Length (TT: L_OFFS) in 
the tool table. The TNC probes the tool radially during rotation to 
determine the starting angle for measuring the individual teeth. It then 
measures the length of each tooth by changing the corresponding 
angle of spindle orientation. To activate this function, program TCH 
PROBE 31 = 1 for CUTTER MEASUREMENT.
