power recovery

Mastering correct?

Machine data for correct type?

Absolute accuracy?

Tool and Base measured correctly?

Also how far is TCP from fllange, where is the exact code you using and how are you testing?

And the robot is moving in a straight line along the ruler or does it move along a curve? (camera perpendicular to ruler?)

Btw. if you you keep on being this much explanatory about what you are doing or have done we will probably keep on this discussion for at least the next half year without any reasonable result.

I personally tend not to invest more time into answers as the person asking is willing to invest in his problem formulation. So if you only describe your problem with a single line you will only get a single line with additional questions.

Try to be a lot more specific. As specific you can be. For example:

Post your program.

Tell us what you have done test your mastering and tool/base measurements are correct.

Tell us how you are sure your machine date is correct. Tell us how the camera is integrated into the kinematic chain.

Show us a video of your setup with the error.

Where is your base?

Where is your tcp?

How is the ruler located in reference to robot?

...

Anything you have basically.

Fubini