4x4 gantry racking badly *fixed*

Instantly hit the black friday sale and received my shapeoko 5 pro yesterday. Finished putting it together today and the excitement built. Downloaded carbide motion, initiallized and the problems started. First (and i still dont understand this) the limit switches illuminate red when they are reached…sometimes. other times they seem to work but dont light up. Anyway, when the gantry moved to the far right rear corner there were some odd noises but when trying to jog it forward it racked really badly. The right side of the y axis seemed to move 2 inches before the left so the gantry was at 80 degree angle while moving. Similarly, hen returning to the back, the left side would hit the limit switch but the right would continue driving back returning the gantry to square but the process repeated everytime i moved it forward.

After looking a while i made sure both y rails were square (my first thought with the racking), changed a limit switch with the included spare, and ultimately figured out that i could rotate the right ball screw with two fingers to jog it a few millimeters and i couldnt move the left with both hands and the full rear position. Removed the servo motor, same problem, played with the anti backlash nuts, same problem . Finally loosened the four screws that hold the stepper motor coupling and smooth as butter. Easily turned with 2 fingers and it moved very smoothly for the first time. It was off just enough that the closer the gantry got to the rear the tighter it got until the stepper was unable to drive it forward at the speed.the right side could causing the racking. Hope this helps some body.

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