Universal Robots Forum

Day to day accuracy

Hi Guys,

I have a problem where the accuracy of my UR3e robot is out by a couple of mm each day. So I’ll set up the robot and it will work for the day but when I restart the robot the next day the accuracy has moved out by ~2mm in any direction or X and Y axis. I’m using it for dispensing Poly Urethane into a grove so I need the accuracy to be on point, so to speak…

I’ve set up a plane and it seems to be accurate, I’ve set up the TCP and it seems to be ok as well…Does anyone else have this problem?

Thanks

Tim

Hi Tim!

Any objections to posting a picture of your cell? More often than not issues with drift are a result of mounting issues (rigidity, etc).

If we take a look at that and still do not see an issue, I would advise you to open a service ticket as the robot should not be drifting from day to day.

Rob

Is it possible your nozzle is moving and not the UR?

My thinking is the nozzle might be rubbing against the product causing alignment issues, I have seen this when a dispense tip gets a ‘booger’ of dried material, that builds up and hits the part over time.

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Thanks Guys,

I found out that the jig - we paid for - wasn’t level. I discovered it when I throw some wild co ordinates at the robot and saw the tip move the jig!!! One of the legs on the jig was 3mm higher causing the issue.

Thanks for your help though!!!

Tim

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My rule of thumb is always trust the robot, the fixture / part are way more suspect.

Glad you fixed your issues.