C4 Maintenance  6. Joint #2 
 
80  C Series Maintenance Manual Rev.2 
Removal: Joint #2 Reduction gear unit 
1.  Remove the following covers. 
For details, refer to C4 Maintenance: 3. Covers. 
Arm #1 top cover 
Arm #1 side cover   
Arm #2 side cover 
Arm #3 head cover 
User plate 
When removing the user plate, remove the following parts as well. 
 D-sub 9-pin connector 
 4 air tubes 
2.  Remove the Joint #2 timing belt. 
For details, refer to C4 Maintenance:  6.3 Joint #2 – 
Replacing the Motor, Removal steps (1) through (4). 
 
Pulley 1 
Timing belt 
Pulley 2 
 
3.  Remove the cable unit. 
For details, refer to C4 Maintenance: 4.1 Replacing the Cable Unit, removal steps (9) through (26). 
4.  Pull out the cables from the Arm #1. 
5.  Turn the Manipulator laterally with the motor pulley facing down 
 
 
CAUTION 
■ 
When turning the Manipulator laterally, there must be two or more people to work 
on it so that at least one of them can support the arm while the other 
is removing 
 
Removing the bolts without supporting the arm may result in the arm falling, bodi
ly 
injury, and/or malfunction of the robot system.