Dort,
This is from my memory, and I'm old.
When this started on ours, we had to take it apart, clean it, lube it and put it back together. We used a high quality, light weight, lithium grease, but were never really satisfied. There must be a better grease for aluminum.
Getting the set screws on the plates set just right is tricky. They have to be even. Too tight and it will bind near the ends of the X and Y travel. Too loose and the bed twists too much. If I remember it was adjust each screw until tight and then back-off 1/8 turn, repeating several times until all were set the same.
The reason ours would bind at the travel extremes was because the rails were worn in the center more than at the extremes from normal use.
Poor planning on your part does NOT constitute an emergency on my part!