Hi, I have a Openbuilds 1050 been working great for a few years now. But now the left side of my Y is not moving the same pace (dragging) as my right side. Could it be that the Nut Block is stripped. I don't see any other issues. The motors spin ok, the rail turns on, I put a new coupler on thinking that was the issue. I am clueless. Any suggestions? I just ordered 2 Nut Blocks.