I followed your steps exactly - with no success. But I tried to figure out the problem again and for me it seems easy: - I wrote with the pen 90 Degrees to the surfase and the point on the iPad is exactly the point I touced with the tip. - Then I moved the pen down and the smaller the arc gets, the refernece point on the iPad is moving. If I think, that the reference point in the stylus is not in the tip but a little bit higher, than a correction factor would be good - or the stylus should check the position arc and correct it by itself. Btw: The corrections seems only to be necessary in the x