5. FEED FUNCTIONS
No override can be used for some commands.
When a one–digit number from 1 to 9 is specified after F, the feedrate
set for that number in a parameter (Nos. 1451 to 1459) is used. When
F0 is specified, the rapid traverse rate is applied.
The feedrate corresponding to the number currently selected can be
increased or decreased by turning on the switch for changing F1–digit
feedrate on the machine operator’s panel, then by rotating the manual
The increment/decrement, ∆F, in feedrate per scale of the manual pulse
generator is as follows:
Fmax : feedrate upper limit for F1–F4 set by parameter (No.1460), or
feedrate upper limit for F5–F9 set by parameter (No.1461)
X :any value of 1–127 set by parameter (No.1450)
The feedrate set or altered is kept even while the power is off. The current
feed rate is displayed on the screen.
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 range of feedrate command value.
D One–digit F code feed
D Cutting feedrate clamp