all the diagonal rods were adjusted to the same length, 198.5mm horizontal radius is 164 and printable radius 105, all the offsets are measured and on the mega2560 and rumba board with marlin firmware everything worked fine. i even accomplished a bed levelling of 0.02mm with manual calibration and a micrometer clock installed instead of a print head. So you can see how i'm about getting a slight head pain out of this, lol. I really don't know what i am doing wrong. I also don't use the automatic bed levelling because it just failed to much in the past, i already spend a reasonable amount of time in mechanical perfecting the bed levelling to get it mechanically levelled. At least you are showing interest in the whole matter, for the marlin fw i had to figure out everything on my own, i needed over a week just to figure out how to compile the damn thing, lolThanks for quick responses