HEIDENHAIN TNC 620 User Manual page 216

5
Tools
5.2 Tool data
Caution: Danger to the workpiece and tool!
Switch off the automatic tool change with M102 if
you are working with special tools (e.g. side mill
cutter) because the TNC at first always moves the
tool away from the workpiece in tool axis direction.
Depending on the NC program, the machining time can increase as
a result of the tool life verification and calculation of the automatic
tool change. You can influence this with the optional entry element
BT (block tolerance).
If you enter the M101 function, the TNC continues the dialog
by requesting the BT. Here you define the number of NC blocks
(1 - 100) by which the automatic tool change may be delayed. The
resulting time period by which the tool change is delayed depends
on the content of the NC blocks (e.g. feed rate, path). If you do not
define BT, the TNC uses the value 1 or, if applicable, a default value
defined by the machine manufacturer.
The more you increase the value of BT, the smaller
will be the effect of an extended program duration
through M101. Please note that this will delay the
automatic tool change!
Use the formula
of an NC block in seconds
starting value for BT. Round up to the next odd
integer. If the calculated result is greater than 100,
use the maximum input value of 100.
If you want to reset the current age of a tool (e.g.
after changing the indexable inserts), enter the value
0 in the CUR_TIME column.
216
BT = 10: Average machining time
to calculate a suitable
HEIDENHAIN | TNC 620 | ISO Programming User's Manual | 9/2016