Robot Jerks to position when powered up

Technical Questions
1

Hello,

We have a UR3e we have been operating for a few years now. Over the past half year or so, we have been noticing that the robot is drooping a bit more when powered down when not in use. By about half an inch, unloaded except for the weight of the gripper(2F-85).

This results in the arm jerking to position when it is powered on again. For the next session. Typically we hear the breaks disengaging simultaneously. Now the power on sequence takes a couple seconds while the joints jerk into position, some locks disengaging before others over the period of a couple seconds.

Could this be an indicator that the breaks are wearing out or components need servicing? How much of a droop in position is acceptable?

2

The robot should not care about its position when it initializes (disengages the brakes). Neither how it returns to its start position - that’s handled by the robot program.

You should be able to check the brakes by trying to rotate each joint inidividually while it’s powered off. :slight_smile:

You can also do an update of the software. UR has been changing the brake disengage sequence a couple of times through the updates. It might give the robot a smoother initialization. :slight_smile: