I think my stylus is worn asymmetrically on my Briot Acurra CX . I bought it used with about 30,000 cuts on it. I can trace a rectangular or square pattern and it edges nicely. When I trace a rectangular shaped frame it does not produce a nice line. Is the original radius at the tip of the stylus 3mm? It has an older Scanform IV in it. Are parts available? Anybody reshape one and recalibrate it. It looks like something and old engineer like me could tackle. Is the Scanform VI stylus backward compatible? It looks like they could be used.