Y Axis not moving smoothly or accurately

Been using my OF for a little over a year and then just started getting two issues that are related. Y axis is not traveling right. First issue is one I’ve read about, in high speed jog, the gantry brakes hard and stalls. In any of the slower speeds or in high speed with the stick not fully engaged, it moves fine. The bigger issue is that during job cuts, the y axis is not moving to the right locations. Example, on a three line text cut the second and third line ended up being cut in the same spot instead of the 3rd line of text being cut below the second. This exact same project had been done weeks earlier and the results were perfect multiple times, so I can eliminate toolpath mistakes. I’ve cleaned the rails and screws on both sides but stopped short of taking anything apart. Can some please help me in the right direction… obviously, I’m just a hobbyist with little experience.

Hey Brent,

this could be 1. insufficient rectangularity of X to Y axes, it can lead to blocking ball nut sometimes. For adjustment of rectangularity see here and here. Or it could be 2. this (but you said you cleaned the ball screws. Did you loosen ball nuts and looked inside for dust-oil mix?). But 3. this reminds me of this

I think I am having the same issue the home is in the right spot and when we start the cut it started at the bottom of the material and off the board and i have it at the top of the material. It is off by 12 inches. Not sure what to do or what is wrong.

Thank you for the links, it ended up being a combination of two problems. First, I realized that I had only partially cleaned the ball nuts on the Y-Axis. I went to the YouTube video and followed it…How to clean the ball nut on the Onefinity CNC // Support - YouTube , that clearly needed to be done. However I still had the issue but not to the same extent. I then checked the square of the rails which had shifted out of square slightly. After I realigned the rails, the issues I had been having stopped and the same cut that failed this morning went off with no issue tonight. The high speed jog worked fine, as well.
Thank you very much for your help.