Mitsubishi Electric M700V Series Manual page 47

4.2.3 Inverse Time Feed
M720VW
M system △
L system ―
During inside cutting when machining curved shapes with tool radius compensation applied, the machining
speed on the cutting surface becomes faster than the tool center feedrate. Therefore, problems such as
reduced accuracy on the cutting surface may occur.
This reduced accuracy can be prevented with inverse time feed. This function can, in place of normal feed
commands, issue one block of machining time (inverse) in F commands. The machining speed on the
cutting surface is constantly controlled, even if radius compensation is applied to the machining program that
expresses the free curve surface with fine segment lines.
Note that when the calculated machining time exceeds the cutting feed clamp speed, the F command value
in the inverse time feed follows the cutting feed clamp speed.
Regular F command
(f)
(b) Actual machining speed
(c) Large
(d) Small
(f) F command
Command format is as shown below.
G93 ;
Inverse time feed (G93) is a modal command and is valid until feed per minute (G94) or feed per revolution
(G95) is commanded.
G00 Xx1 Yy1 ;
G93 ;
G01 Xx2 Yy2 Ff2 ;
G02 Xx3 Yy3 Ii3 Jj3 Ff3 ;
G94(G95) ;
In movement blocks, since processing time is commanded to a line segment, command the feedrate "F"
each time.
M730VW M750VW M720VS
△ △
― ―
Inverse time feed
(b)
(c) (d)
(b) Same
(f) F command
Inverse time feed
→ Inverse time feed mode ON
→ In inverse time feed mode
:
→ Inverse time feed mode OFF
M700V Series Specifications Manual
M730VS M750VS
△ △ △
― ― ―
(f)
4 Feed
(b)
III - 45