Hello Guys,
An update on this issue. We have been successfully able to resolve this issue. I ll try to explain what happened and what we did.
So the Kuka has a payload (spindle) of 35kg ,which has been attached to the arms with the help of a transition steel bracket which converts circular flange of the kuka to a rectangular mounting plate on spindle side .The bracket itself is a welded assembly.
Initially , when we assembled the spindle with the transition piece and mounted on the robot , it yields a 4 degree angle in the ball mill tool when measured via a digital level. So in order to make it perfectly vertical we override the advised calibration method and aligned the A6 manually via digital level.
Yesterday, we decided to follow the standard procedure by calibrating the A6 with the dial guage and modifying the bracket to make the tool vertical. We did it and it works fine now in z axis.
There are some other issues as well with the accuracy of the robot which I will post in another thread.
Thanks
Junaid Abbas