Hello, Thank you very much for everything Chris, I find it an amazing project. I am connecting the AR3 in an aluminum version, I carried out the calibration tests and it ends successfully, after a while of manipulating the arm, on the screen the position of J5 begins to advance until it exceeds the maximum values, without the arm physically move, after that I can no longer control the arm as it thinks it is out of calibration. What could be happening? before this happens the motors work well in both directions and as I wrote earlier it calibrates well. I'll go over the diagram again. Thank you very much for reading and any comments are welcome.