I just got my XXL a few days ago and started the build process last night. I noticed that the left and right Y carriages have very different tolerances for the v channel wheels.
The left side carriage slid right onto the extrusion and rolled very freely. It even has 1/8 - 1/4" play if I try lifting the carriage straight up.
But the right side carriage is extremely tight to the extrusion rail. I had to give it a healthy push to get the rail between the wheels. It’s lined up dead center on the v channel, but it’s tight. It will roll but it doesn’t go where you don’t push it.
I suspect one side is wrong. Which one needs adjusting?