YASKAWA yasnac lx3 - Page 58

2.8.19 TOOL NOSE RADIUS COMPENSATION
(G 40
THROUGH G 44)+ (Cent’d )
(6)
Movement in compensation mode (Cent’d)
c.
Programming consideration in compensation
mode
(i) Be careful not to program a
shaped cutting contour.
wedge-
(a) Wrong
T-
T–
M 96
Q-
4“
‘IY.---”~---” ------- ~;;::oo,
-=:: --.–_.:,___________
i
f ;l&cJp,4::
INTERSECTION IS FAR AWAY
NOSE OF
GET IN
(b) Correct
T+
T
\l 97
~
; j
\f 97
-------
i-
------
_ PROGRAM IS MADE SO
Q
THAT TOOL NOSE OF
------
1
2 R CAN GET IN THE
WENDGE
L ---—-.
1
(ii)
Program the tool movement so that the
tool nose of 2R diameter can be in the
contour,
(a) Wrong
PROGRAMMED CONTOUR
(b) Correct
PROGRAMMED CONTOUR
/
d.
e.
Command involving no movement in compen-
sation mode
The control normally reads two blocks ahead
during tool radius compensation mode and
calculates the tcml path. If either of these
blocks gives no coordinate instructions such
as G04 (dwell) , the control reads a block
further ahead and makes calculations. When
coordinate instructions are missing in three
or more blocks , tool radius compensation be-
comes impossible and accurate tool path can–
not be obtained.
Therefore, in a program
where G41 to G44 are used ensure that, after
them , two or more blocks without movement
command in the compensation plane will not
follow .
GO1 G41 F.. .
G04 U.. . ;
M.. . ;
1
;
Compensation is normally
made by the two or less
blocks without move command.
M40 ;
If no
movement instruction is programmed
in three consecutive blocks ,tool center is
offset on the normal line at the end point
of the block immediate before them.
Use of dummy blocks
If it is impossible to specify a move command
in three or more consecutive blocks and the
offset on the normal line is not satisfactory,
a dummy block may be inserted.
The dummy block does not cause an actual
movement.
This block is specified for the
purpose of providing the data necessary for
the tool nose radius computation. For the
address of this dummy command, I and K
are used.
I: X-axis dummy command (incremental) .
K : Z -axis dummy command (incremental) .