HEIDENHAIN TNC 640 (34059x-05) Cycle programming - Manual (Page 426)

Cycles: Turning
12.31 GEAR HOBBING (Cycle 880, DIN/ISO: G880)
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426
TNC 640 | User's Manual Cycle Programming | 1/2015
Please note while programming:
The values entered for module, number of teeth and
outside diameter are monitored. If these values are
not consistent, an error message is displayed. It is
also possible to make entries for only 2 of these 3
parameters. In this case, enter the value 0 for either
the module or the number of teeth or the outside
diameter. The TNC then calculates the missing value.
Program FUNCTION TURNDATA SPIN VCONST:OFF.
If you program FUNCTION TURNDATA SPIN
VCONST:OFF S15, the spindle speed of the tool is
calculated as follows: Q541 x S. With Q541=238 and
S=15, this would result in a tool spindle speed of
3570 rpm.
Define the tool as a milling cutter in the tool table.
To avoid exceeding the maximum permissible spindle
speed of the tool, you can enter a limitation. (Entry in
the "Nmax" column of the tool table "tool.t".)
Before starting the cycle, program the direction of
rotation of the workpiece (M303/M304).
Before cycle call, set the datum to the center of
rotation.
Cycle 880 Gear Hobbing is run in turning mode and is
CALL-active.
Software option 50 must be enabled
Danger of collision!
Pre-position the tool so that it is already on the
desired machining side Q550. On this machining
side, move the tool to a safe position where there is
no danger of collision with the workpiece (clamping
devices) during tilting.
Please note that the starting point in Z and the end
point in Z are extended by the set-up clearance
Q460! Clamp the workpiece in such a way that there
is no danger of collision between the tool and the
clamping devices!
If you program M136 before the cycle, the TNC
interprets feed rate values in the cycle in mm/rev.,
and if you are not using M136, in mm/min!
After Cycle 880 GEAR HOBBING remember to call
Cycle 801 and M145 in order to reset the coordinate
system.
If you abort a program during machining, you must
reset the coordinate system with Cycle 801 and
call M145 before you start machining again!