(Common to Power Mate i–D and –H)
5. FEED FUNCTIONS
No override can be used for some commands.
After specifying G95 (in the feed per revolution mode), the amount of
feed of the tool per position coder revolution is to be directly specified by
setting a number after F. G95 is a modal code. Once a G95 is specified,
it is valid until G93 (rate function) or G94 (feed per minute) is specified.
An override from 0% to 254% (in 1% steps) can be applied to feed per
revolution with the switch on the machine operator’s panel. For detailed
information, see the appropriate manual of the machine tool builder.
Feed amount per position coder
revolution (mm/rev or inch/rev)
Fig.5.3 (c) Feed per revolution
When the speed of the position coder is low, feedrate
fluctuation may occur. The slower the spindle rotates, the
more frequently feedrate fluctuation occurs.
A common upper limit can be set on the cutting feedrate along each axis
with parameter No.1422. If an actual cutting feedrate (with an override
applied) exceeds a specified upper limit, it is clamped to the upper limit.
Parameter No.1430 can be used to specify the maximum cutting feedrate
for each axis only for linear interpolation and circular interpolation.
When the cutting feedrate along an axis exceeds the maximum feedrate
for the axis as a result of interpolation, the cutting feedrate is clamped to
the maximum feedrate.
An upper limit is set in mm/min or inch/min. CNC calculation
may involve a feedrate error of ±2% with respect to a
specified value. However, this is not true for
acceleration/deceleration. To be more specific, this error is
calculated with respect to a measurement on the time the
tool takes to move 500 mm or more during the steady state:
See Appendix C for the feedrate range.
Feed per revolution
Cutting feedrate clamp