
7. Feed Functions
7.5 Inverse Time Feed; G93
115
Relation with other functions
(1) Scaling (G51)
When using a scaling function, issue a F command for the shape after scaling. For example, if
a double-size scaling is carried out, the machining distance will be twice. Thus, if executing a
cutting at the same speed as that of before scaling, command the value (F’) calculated by
dividing F value by the multiples of scaling.
Feedrate (mm/min)
F =
Distance (mm)
F
F'=
2
Shape after scaling (Double size)
F
(2) High-speed machining mode II (G05P2)
With the inverse time feed (G93) modal, high-speed machining mode II (G05P2) is operated in
the inverse time feed mode, instead of high-speed machining mode. High-speed machining
mode will be valid when the inverse time feed mode is canceled.
(3) If the speed calculated in the G93 mode exceeds the speed range at the feed per minute,
clamping is performed at the clamp speed set with parameters.
(4) The program error (P125) will occur when the commands below are issued in the inverse time
feed (G93) mode.
G code
Function
G02.3, G03.3
Exponential interpolation
G06.2 NURBS
interpolation
G12
Circular cutting CW
G13
Circular cutting CCW
G31~G31.3 Skip
G33 Thread
cutting
G34~G36, G37
Special fixed cycle
G37.1
Automatic tool length measurement
G73~G89 Fixed
cycle
G96
Constant surface speed control ON
(5) The program error (P125) will occur if inverse time feed (G93) is commanded in the following
modes.
G code
Function
G02.3, G03.3
Exponential interpolation
G33 Thread
cutting
G73~G89 Fixed
cycle
G96
Constant surface speed control ON