
B–65162E/03
11. OPTION RELATED TO SPINDLE
449
Example of calculation
(1) Number of feedback pulses per motor rotation = 1024
Spindle–to–motor speed ratio (m/n) = 1:3 (speed reduction)
χ=
1024
1024
1
3
+ 0.3
Thus, χ is rounded up to 1.
Hence, positioning repeatability = "(1 x 0.2) = "0.2°
(2) Number of feedback pulses per motor rotation = 512
Spindle–to–motor speed ratio (m/n) = 2:1 (speed up)
χ=
1024
512
2
1
+ 4
Thus, χ = 4
Hence, positioning repeatability = "(4 x 0.2) = "0.8°
(3) Number of feedback pulses per motor rotation = 512
Spindle–to–motor speed ratio (m/n) = 1:2 (speed reduction)
χ=
1024
512
1
2
+ 1
Thus, χ = 1
Hence, positioning repeatability = "(1 x 0.2) = "0.2°
(4) Number of feedback pulses per motor rotation = 512
Spindle–to–motor speed ratio (m/n) = 1:1
χ=
1024
512
1
1
+ 2
Thus, χ = 2
Hence, positioning repeatability = "(2 x 0.2) = "0.4°