C4 Maintenance  10. Joint #6 
 
138  C Series Maintenance Manual Rev.2 
Installation: Joint #6 motor 
When tightening hexagon socket head cap bolts, refer to the 2.4 Tightening Hexagon Socket 
Head Cap Bolts. 
 
1.  Install the motor plate to the Joint #6 motor. 
Hexagon socket head cap bolts: 2-M4×12 
Tightening torque: 4.9 N·m (50 kgf·cm) 
 
Be careful of the direction of the motor plate. (See the photo.) 
 
 
2.  Mount the Joint #6 electromagnetic brake to the Joint #6 motor 
unit. 
Hexagon socket set screws: 3-M2.5×10 
 
Be careful of the direction of the Joint #6 electromagnetic brake 
wiring. (See the figure.) 
Electromagnetic   
brake wiring 
 
 
3.  Mount the drive boss and the pulley 1 to the Joint #6 motor unit. 
 
Set the drive boss and the pulley 1 so that their surfaces become 
flat. 
Hexagon socket set screws: 2-M3×8 (with a brass bushing) 
 
Set the pulley 1 and the motor shaft. 
Leave 0.5 mm for the electromagnetic brake. 
Hexagon socket set screws: 2-M3×8 (with a brass bushing) 
 
Set the set screws as indicated below. 
 
 
 
Pulley 
 
Motor shaft 
Drive boss 
 
A :  Pulley and   
motor shaft fixing screws 
B : Pulley and   
drive boss fixing screws 
C : Bushing 
D : Flat face for motor shaft 
E : Flat face for drive boss 
 
A 
A 
B 
C 
C 
B 
D 
E