I have a 1510 with lead screws and a XYZ touch plate and I noticed that my project vcarve with a border was not centered on the material. I did a calibration and it is dead on.
Need more detail. How far off? Did you measure you stock correctly? Did you measure your endmill correctly? Was in not centered in X and Y or just one of them? Pictures with details, gcode files and vectric file can really help us help you.