12 - 15 
MELSEC-Q
 
12   CONTROL SUB FUNCTIONS 
 
(1)   For "Ball screw" + "Reduction gear" 
When the ball screw pitch is 10mm, the motor is the HC-MF (8192 
PLS/rev) and the reduction ratio of the reduction gear is 9/44. 
 
M
Machine
Reduction ratio 9/44
 
 
First, find how many millimeters the load (machine) will travel (
S
) when 
the motor turns one revolution (AP). 
 
 
•
 AP(No. of pulses per rotation) = 8192 
 
•
 
S
(Machine travel value per motor revolution)  
= Ball screw pitch
 
 
Reduction ratio 
= 10 [mm]
 
 
9/44 
= 10000.0 [
µ
m]
 
 
9/44 
 
Substitute this for the above expression (1). 
At this time, make calculation with the reduction ratio 9/44 remaining as a 
fraction. 
AP 
8192  
S
 
= 
10000.0 [
µ
m]
 
 
9/44 
 
 
8192
 
 
44 
 
 
= 
10000.0
 
 
9  
360448    
 = 
90000.0    
45056   45056 (AP) 
 = 
11250.0  
= 
11250.0 (AL)
 
 
1 (AM) 
 
45056 (AP) 
 
 
= 
1125.0 (AL)
 
 
10 (AM) 
 
 
Thus, AP, AL and AM
 
to be set are as follows. 
AP 
= 45056  …...
Pr.2
 
 AP 
= 45056  ….
Pr.2
 
AL 
= 11250.0  …
Pr.3
 
or AL 
= 1125.0  …
Pr.3
 
AM 
= 1  …………
Pr.4
 
 AM 
= 10  ………
Pr.4
 
 
Note): These two examples of settings are only examples. There are 
settings other than these examples.)