I’ve had my XL for exactly a year. I’m a newbie to CNC so it took me a while to figure out that I had a backlash problem.
My issue was caused by loose belts. No matter how often I tightened them. they always came loose again, particularly the x axis. All I had to do to know that there would be a problem is turn my machine on and check for x-axis play.
The issue appears to be the clamps that, when tightened properly, should hold the folded belt teeth against each other and prevent slippage. Mine do not. Slippage is almost instantaneous. I fan hear the teeth moving past each other.
My dumb solution was to C-clamp the belt teeth against each other and against the aluminum carriage. The C-clamp doesn’t hold the belt well, so I used a small piece of 1/8 plywood above the belt.
Many folks won’t like this solution because it cuts the useable width of the bed and makes the limit switches unusable without gluing a block to the plywood holding down the belt. Neither is a problem for me as I have never used the full width of my XL.
Hope this helps someone.
As an aside, I found C-clamps to be a good way to hold the belt in position as I am adding tension.