Tramming issue - 1/4" Gap between Y2 from plate and X-axis plate

[ScottsdaleSteve (Steve)]

See these threads from way back. I had the same issue. Shims in the correct places will make it square.

Help! 3XL base is square but carriage is not!

My 3XL was out of square when I first assembled it, in exactly the same way as yours is now. The ends of the “X” extrusion were not perfectly square, requiring shims as described in the following old thread: Not sure why yours went from square to not square, but perhaps it needs shimming…

Yet another xxl squaring issue

I had the exact same issue on my XL, though only a 1/4" gap in the same places (back left/front right). I don’t think you’re shimming in the correct spots. You need to shim the X rail in the places indicated (back of the left end; front of the right end). I used a stack of 3 slivers of aluminum from a Coke can in each spot and it closed the gap exactly. If you look closely, you can see the shim in the second picture. Coke can wall thickness is ~ .004" thick, so with 3 layers my total shim wa…