VT6L Maintenance    19. Calibration 
 
174  VT series Maintenance Manual    Rev.2 
 
CAUTION 
■ 
Normally, release the brake of 
joints one by one. Take extra care if you need to 
release the brakes of two or more joints simultaneously
. Releasing the brakes of 
two or more joints simultaneously may cause hands and fingers to be caught 
and/or equipment damage or malfunction of the Mani
pulator as the arms of the 
Manipulator may move in unexpected directions.
 
Be careful of the arm falling when releasing the brake.
 
While the brake is being released, the Manipulator’s arm falls by its own weight
.   
The arm falling may cause hands and 
fingers to be caught and/or may cause 
 or malfunction of the Manipulator. 
Also, pay attention to the following points at the encoder initialization. 
 
 
CAUTION 
■ 
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 
or pinched and it ma
y 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 “VT series Manual VT6L Manipulator 3.9  Checking the Basic 
”. 
Torsion of the internal cables can be checked by removing the fol
lowing cover. 
Joint #4  :  Arm #3 Cover   
 
 
Arm #3 Cover 
3-M4×12 Sems 
 
For details on Jog & Teach, refer to the following manual. 
EPSON RC+ User’s Guide 
 5.11.1 [Tools]-[Robot Manager]-[Jog and Teach] Page 
 
-  For details about the basic orientation, refer to “VT series Manual VT6L Manipulator 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.