Fagor CNC 8070, Programming Manual

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Programming manual
CNC 8070
T
E
CH
NOLOGI
CAL FUNCTI
O
NS
Feed
ra
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e
la
ted f
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5.
(S
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V02.0
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)
61
5.2.3 Constant feedrate mode (G197/G196)
With these functions, it is possible to choose whether the feedrate at
the tool center is maintained constant while machining or the feedrate
at the cutting edge so when working with tool radius compensation,
the programmed "F" corresponds to the contact point between the
part and the tool.
Programming
The functions related to the feedrate type are:
G197 Constant tool center feedrate.
G196 Constant cutting point feedrate.
These functions may be programmed anywhere in the program and
they don't have to go alone in the block.
G197 Constant tool center feedrate
After executing G197, the CNC interprets that the programmed "F"
corresponds to the tool center. This means that the feedrate at the
cutting point increases on inside arcs and decreases on outside arcs.
G196 Constant cutting point feedrate
After executing G196, the CNC interprets that the programmed "F"
corresponds to the contact point between the tool and the part. This
results in a uniform part surface even on arcs.
Minimum radius for applying constant feedrate
Using the instruction "#TANGFEED RMIN [<radius>]" a minimum
radius may be set so that constant tangential feedrate is only applied
on those arcs whose radius is bigger than the minimum set. If it is not
programmed or it is set to zero, the CNC will apply constant tangential
feedrate on all the arcs.
The minimum radius is applied from the next motion block on and it
keeps its value after executing G197.
Constant cutting point feedrate:
Where:
F
P
Programmed feedrate.
R Path radius.
r Tool radius.
F
R
R
R r +
------------ F
P
⋅
=