Epson C Series Maintenance Manual page 146

C4 Maintenance 9. Joint #5
15. Unscrew the set screws of the circular spline and the flexspline.
Circular spline fixing bolts:
Hexagon socket head cap bolts: 3-M2×10
Flexspline fixing bolts:
Hexagon socket head cap bolts: 6-M3×8
The parts are greased. Wipe grease on the parts while removing
them.
16. Remove the circular spline and the flexspline.
The parts are greased. Wipe grease on the parts while removing
them.
17. Remove the O-ring of the housing.
126 C Series Maintenance Manual Rev.2
O-ring