Thanks for thinking with me guys, I appreciate it!
Yes, I know for sure that it isn´t square, nor is the bed level. I still have to make time for this. It´s like you say, if repeatability is ok, then that´s ok for now
I have some 5 meter long Alu L profile from the house renovation laying around. So will cut this in the coming days and mount it to the table.
I have installed the upgraded belt holder, for the GT2 belt. So I know it starts parallel on both sides, but when running from one end to the other, it slowly goes to one side of the table. As it needs to re-align when going back home to the initial belt holder. Will measure the distance between those wheels and report back.
Well I still need to experiment with those settings, for now I use the suggested speeds in the Wiki. So I hope this will not be the reason of the issue.
Regarding the setup; I use the recommended SKR Pro, with steppers in series. So “pretty stock”. I do however still need to find some time to properly work away the wires. So maybe this is part of the cause.
Thing is, if I just mill simple and small items all goes well, longer items, or like a name and it is giving issues.
But you guys gave me things to try, I´ll report back soon.