Siemens SINUMERIK 840D sl, Function Manual

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Detailed description
2.1 Path feedrate F
Basic logic functions: Feeds (V1)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0
23
Both functions
G34
and
G35
imply the functionality of
G33
and additionally provide the option
of programming an absolute lead change value for the thread under
F
. If the start and end
lead of a thread is known, the thread-lead change can be determined using the following
equation:
_N
H
ದ N
D
_
)
O
*
The identifiers have the following meanings:
F:
The thread-lead change to be programmed [mm/rev
2
k
e
: Thread lead of axis target point coordinate, thread axis [mm/rev]
k
a
: Initial thread lead (programmed under I, J or K) [mm/rev]
l
G
: Thread length [mm]
The absolute value of F must be applied to
G34
or
G35
according to the desired lead
increase or lead decrease.
When the thread length l
G
, lead change
F
and initial lead k
a
are known, the lead increase at
the end of block k
e
can be determined as follows by modifying the formula:
•
G34
(progressive lead):
N
H
N
D
)O
*
•
G35
(degressive lead):
N
H
N
D
)O
*
Note
If the formula results in a negative root expression, the thread cannot be machined!
In this case, the NC signals alarm 10605 or alarm 22275.