(3)
a.
The direction of compensation is changed
from + to – or - to + during program execu-
tion.
G40 or T~ U 00 command should not
be necessarily programmed to cancel the
tool nose radius compensation.
G code designation (G40 to G44)
G code of tool nose radius compensation
(G41 to G44)
One of G41, G42, G43 and G44 and T code
should be programmed before the execution
of tool nose radius compensation.
These
four G codes specify the relationship be-
tween the virtual tool nose and the tool
center.
-Ku2)’-
VIRTUAL
TOOL TIPS
Q>l
t
t
R
L=-
-Z
G 43
\
‘ G~~
TOOL
CENTER
Fig. 2.30
Regardless of the mode of tool nose radius
compensation, the current position of the
virtual tool nose is displayed by depress–
ing the POS pushbutton.
b. Issue G40 to cancel the tool nose radius com-
pensation.
c. Cautions in programming G code
(i)
Since G40 to G44 are modal G codes of
06 group, they are retained until the
other G code is commanded. Before
switching one of G41, G42, G43 and G44
to another, G40 must be intermediated to
cancel the compensation.
El
G 42
c1
G41
\
/
v +’
n]
G ‘NJ
// \\
c1
G 43
c1
G 44
(ii)
When the power supply is turned on, G40
is in effect.
(iii) When the RESET button is depressed, G
code of 06 group are cancelled and G40
becomes effective.
(4) Tool motion on the tool nose radius compen-
sation
a.
Fig.
2.31. shows the outline of the tool
motion .
...
..>
BLOCK OF
~,
COMPENSATIOh
+x
WITH G 00
‘:3;,
Fig. 2,31
When the compensation is cancelled, the
programmed contour meets with the path
of virtual tool tip ( @ and @) .
In compensation mode, the tool center
path is deviated by radius from the pro-
grammed contour.
Therefore, the path
of virtual tool nose does not meet with
programmed contour. But the current
position displayed by depressing POS
ke is the position of virtual tool tip
( bto @).
(iii)
(iv)
b,
The (connection between two blocks in
compensation mode is provided by the
intersection of tool center paths (M97)
and I:)y the circular arc (M96) . In the
above diagram,
blocks 3 and 4 are con-
nected by a circular arc.
Block @ for compensation start and
block @ for compensation cancel per-
form the connection of compensation
mode and compensation cancel mode.
Program should be made carefully for
these blocks.
Relationship between tool nose radius com-
pensaticm and tool position offset
Tool nose radius compensation apply to
the programmed contour which has been
offset by the tool position offset function.
47
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