
6. INTERPOLATION FUNCTION
B–63833EN–1/02
266
Tool movement can be synchronized with spindle rotation when cutting
threads.
The spindle speed is continuously read through the position coder
attached to the spindle. Then, it is converted to a cutting feedrate (feed
per minute) to feed the tool.
L
Straight Thread
L
L
Tapered Screw
Scroll Thread
L : Lead
In general, thread cutting is repeated along the same tool path in rough
cutting through finish cutting for a screw. Since thread cutting starts when
the position coder mounted on the spindle outputs a 1–turn signal,
threading is started at a fixed point and the tool path on the workpiece is
unchanged for repeated thread cutting. Note that the spindle speed must
remain constant from rough cutting through finish cutting. If not,
incorrect thread lead will occur.
6.4
THREAD CUTTING
6.4.1
Thread Cutting
General