You mean motor wiggling? I think not
Maybe that or maybe some other part. If something comes loose, it might not work as well.
@Ricardo_Kevin
I also have a CoreXY and found that I had two issues affecting circles - some drag on the Y carriages and a different travel amount for the x and y motors. I found I had to change one by a small amount of steps for one motor in the firmware to make both X and Y travel distances measure the same.
It’s backlash, missing steps, or skewed axi. Make a giant square just 3mm - your build volume, print it, and see if the square gets closer or even falls into an edge anywhere.
+Scott Lewis how to decrease the drag?? Or by changing a little ammount from the steps/mm can solve this???
What do you mean by make a giant square just 3mm? @JuicyMoose_Productio
Like a skirt, one or two permitter hollow cube/square that is 3mm shorter on each side of your build volume.