Y Axis lag?  

Y Axis lag?

Hello!

So, today I replaced my Y axis bearings with these: 8UU FMC08 PBC Linear Bearings

They seem great. The Y axis carriage as no play, and slides smoothly without noise. However, since, I've seen this strange Y "lag" as best I can describe it. It seems as if there is a slight, but consistent delay in the Y axis movement. This results in circles having pointed areas where the Y axis accelerates, and squares being ever so slightly bent on one side. These artifacts are completely consistent up the Z axis.

Here's some examples on a Benchy:

The round stack on top. You can see the bumps on the upper left and lower right where the Y axis lags behind accelerating around the curve.

Here, on the roof of the benchy, you can see the upper edge is not quite straight. It curves on the right side.

There are other artifacts on this benchy that are hard to take a picture of. For instance, many of the ridges around the doors and portholes are flattened and flush with the wall on one side, again seemly due to the Y axis being slow to move.

The Y axis seems to move freely by hand with very little resistance. I did have to reattach and tighten the Y axis belt during replacement, but it seems tight. (And if it were loose I'd expect the issues to not be so consistent up the Z axis)

Any ideas on what to adjust? Should I just give it more time and let the bearings break in?