
3.INTERPOLATION FUNCTION PROGRAMMING B-63944EN-1/02
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3.1 CONSTANT LEAD THREADING (G32)
Tapered screws and scroll threads in addition to equal lead straight
threads can be cut by using a G32 command.
The spindle speed is read from the position coder on the spindle in
real time and converted to a cutting feedrate for feed-per minute mode,
which is used to move the tool.
L
Straight thread
L
L
Ta
ered screw
Scroll thread
Fig. 3.1 (a) Thread types
Format
X
X axis
Z
2
Start point
L
1
End point_
0
Z axis
G32IP_F_;
IP_: End point
F _: Lead of the long axis
(always radius programming)
Fig. 3.1 (b) Example of threading
Explanation
In general, threading is repeated along the same tool path in rough
cutting through finish cutting for a screw. Since threading starts when
the position coder mounted on the spindle outputs a
one-spindle-rotation signal, threading is started at a fixed point and the
tool path on the workpiece is unchanged for repeated threading. Note
that the spindle speed must remain constant from rough cutting
through finish cutting. If not, incorrect thread lead will occur.