
6.INTERPOLATION FUNCTION B-63783EN-1/01
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6.4.2 Threading Based on an Arbitrary Spindle Gear Ratio
Overview
This function sets M:N as the gear ratio between the spindle and position
coder for threading. M and N can be represented using an arbitrary
integer from 1 to 9999.
Threading
To perform threading, the one-rotation signal of the spindle is required
for synchronization between the spindle and Z-axis. So, to perform
threading based on an arbitrary gear ratio by using a motor with a built-
in position coder, the one-rotation signal of the spindle must be sent to
the CNC as shown in Fig. 6.4.2(a). (Fig. 6.4.2(a) shows an example
where a FANUC spindle motor and spindle amplifier are used.)
Fig. 6.4.2 (a) Threading Based on an Arbitrary Gear Ratio
Spindle
moto
M : N
Spindle
Position
detecto
Signal converter
circuit
One-rotation signal
detecto
One-rotation
si
nal
Feedback (P)
Position coder signal
Spindle
am
lifie
CNC
Tool
Workpiece
L
∆Z