Additional Functions; Program Supporting Functions; Fixed Drilling Cycles - Siemens Sinumerik 840D sl Programming Manual

Additional functions

4.1

Program supporting functions

4.1.1

Fixed drilling cycles

The fixed drilling cycles simplify the creation of new programs for the programmer.
Frequently occurring machining steps can be executed with a G function; without fixed
cycles, several NC blocks must be programmed. Thus fixed drilling cycles shorten the
machining program and save memory space.
In the ISO dialect mode, a shell cycle is called which uses the functionality of the Siemens
standard cycles. This way, the addresses programmed in the NC block are transferred to the
shell cycle via system variables. The shell cycle adjusts this data and calls a Siemens
standard cycle.
The fixed drilling cycles are called with the following G functions.
Table 4- 1
G function
G73
G74
G76
G80
G81
G82
G83
G84
G85
G86
ISO Milling
Programming Manual, 06/09, 6FC5398-7BP10-1BA0
Overview of drilling cycles
Drilling Machining at drilling
(-Z direction) base
Interrupted working —
feedrate (delay
possible at each in-
feed)
Cutting feedrate Spindle stop →
Spindle revolution
after dwelling in the
opposite direction
Cutting feedrate Spindle positioning
→ Withdraw lift-off
path
— —
Cutting feedrate —
Cutting feedrate Dwell
Interrupted working —
feedrate
Cutting feedrate Spindle stop→
Spindle start after
dwelling in the
opposite direction
Cutting feedrate —
Cutting feedrate Spindle stop
Return Applications
(+Z direction)
Rapid traverse High-speed deep
hole drilling
Cutting feedrate → Left-hand thread
dwell time → Spindle boring (in the
turns in the opposite opposite direction)
direction
Rapid traverse → Precision drilling
Return lift-off path, boring
spindle start
— Deselection
Rapid traverse Drilling, Preboring
Rapid traverse Drilling,
countersinking
Rapid traverse Deep-hole drilling
Cutting feedrate → Tapping
dwell time → Spindle
turns in the opposite
direction
Cutting feedrate Drilling
Rapid traverse → Drilling
spindle start
4
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