Actually even with the motors disabled and moving the gantry by hand you will find spots that stick, independent of gantry misalignment (which obviously creates extra friction). The issue is that the gap between the side rails is not perfectly consistent, and the super minimal rail riding system doesn’t like this. The side rails, basically, are a little wavy.
I was thinking using 2 ball screws with one stronger motor and tying them together with timing gears and belts. But that will blow the roof off your budget.
Well and they are small steppers, because I took apart a mini delta 3D printer to reuse them. It would be a good idea to upgrade the design to use the more commonly sized 3D printer steppers.
