If anyone on here is well versed with the NX100 platform I could use some assistance. We have a NX100 EA1900n Motoman Robot that is used for welding. Lately I have been experiencing an issue where the robot is off in my programs. What I mean by this is, I am in a manufacturing plant that produces a lot of the same parts in large quantities all day every day. I have programs for all of the different parts we produce and rarely did I ever have to go back and modify these programs based on the robots position.
However over the last couple months, it seems I am constantly having to go and manually modify programs because the robot is no longer in the right spot on the joints to be welded. In some spots of the programs the Robot is right on the weld joint where it should be and then it is off on the next weld joint. Now when I say it is off I am only talking anywhere from 5 to 10 millimeters (maybe more) in any direction, but that is enough to make a weld land in off center in the joint.
We have replaced the batteries in both the controller and the Robot as well as we have replaced the motor/encoder in the U-Axis when it had an issue a while back but the new one was installed properly. We have also kept up on greasing each axis.
I have gone in and checked my home position just about every other day and that seems to be holding just fine. I am wondering if the robot is possibly just getting old and needs to be serviced.
I just want to see if anyone else has any thoughts.