
B–63173EN–1/01
9. SPINDLE SPEED FUNCTION
357
As shown in the figure below a gear can be inserted between the spindle
and spindle motor, and between the spindle and position coder.
Spindle control
Spindle amplifier
Spindle motor
Spindle
Gear ratio n:m
4
Error
counter
Gear ratio q:p
1024 p/rev
Position
coder
(The 512 pulses/rev position coder is incorporated into some
spindle motors. When the serial spindle is used, the system
carries out conversion from 512 pulses/rev to 1024 pulses/rev.)
Up to three gear stages can be provided between the spindle and the
spindle motor. The gear ratio is arbitrary. The spindle move distance per
spindle motor rotation is different, based on the gear ratio. The speed
command to the spindle motor must be adjusted. See (2), below, for addi-
tional information regarding a spindle motor incorporating a position
coder.
The position coder is used to detect the position of the spindle.
The gear ratio for the spindle and position coder is specified in the parame-
ter sets No. 5221 to No. 5223 and No. 5231 to No. 5233, or parameter set
PG1 and PG2 No. 3706 #0, #1. Which parameter set to use is specified
by parameter VGR No. 5200 #1.
This is used if the gear ratio for the spindle motor and position coder
(built-in or separate) is not 1:1, 1:2, 1:4, or 1:8, set VGR to 1 and set the
gear ratio using parameter No. 5221 to 5223.
When position coder is mounted on a spindle, the gear ratio for the spindle
motor and position coder cannot be changed by shifting the spindle motor
and spindle gears. Parameters No. 5221 to 5223 must all specify the same
value for the teeth of the individual spindle gears. Parameters No. 5231
to 5233 must all specify the same value for the teeth of individual position
coder gears.
The 1024 or 512 pulses/rev position coder is built into the spindle motor.
For the 512 pulses/rev version, specify double the number of teeth on each
gear for the position coder. (Double the number of teeth need not be
specified for the serial spindle.)
9.5.2
Connection Among
Spindle, Spindle Motor,
and Position Coder
(1) Gear between spindle
and spindle motor
(2) Gear between spindle
and position coder
S Arbitrary gear ratio
(VGR=1)