K40 Alignment issue?

I am trying to cut some greeting envelopes with dashed lines to make it easy when folding these and I noticed that after folding, the corners are not even. I ended up cutting a simple 11”x 7.5” rectangle with a dashed line in the middle. After folding it, the edges are off by 3 mm.

I checked the alignment and it seems fine. I do not think the belts are worn since I do not use this machine much.

Any idea why this is happening is welcome

Either the frame is not square or the trolley (Yaxis) is not square to the frame.

Is there a way to fix this?

I just checked the frames on they are not exactly @ 90º. Is this something that can be fixed?

image
Can this be fixed?

Although a K40-style machine is not like a bigger CO₂ laser, a recent discussion fixed a non-square gantry by tweaking the belt on one side:

Might not apply exactly, but it’s a place to check.

Thank you,

I will check it

Found an easy way to this