Epson VT Series Manipulator Manual page 258

Also, pay attention to the following points at the encoder initialization.
■ Joint #4 have no mechanical stops and they may be rotated more than 360
degrees. If the encoder initialization is performed with improper posture, the
Manipulator moves outside the operation range. If the Manipulator was moved
outside the operation range, the internal wiring may be damaged by being twisted
CAUTION
or pinched and it may result in Manipulator malfunction.
When the origin position of the Joint #4 is uncertain, check torsion of the internal cables.
The origin position is where the Manipulator has the internal cables not twisted at the
basic orientation described in Setup & Operation 3.9 Checking the Basic orientation.
NOTE

Torsion of the internal cables can be checked by removing the following cover.
3-M4×12 Sems
Arm #3 Cover
For details on Jog & Teach, refer to the following manual.
EPSON RC+ User's Guide
NOTE

- For details about the basic orientation, refer to Setup & Operation 3.9 Checking the
Basic orientation.
- Calibrate one joint at a time. (Also, replace parts of one joint at a time.) If you
calibrate the origins for multiple joints simultaneously, it will be more difficult to verify
their origins and obtain the origin correct positions.
242
Joint #4 : Arm #3 Cover
5.11.1 [Tools]-[Robot Manager]-[Jog and Teach] Page
19. Calibration
VT Rev.1