Istanbulu,
The Mint protractor for the JMW-9 tonearms is made based on the mounting distance of 223mm and effective length of 240mm based on the Baerwald algorithm, which Yip uses for his protractors. The mounting distance of 223mm is what VPI used to officially state on their website before removing it. That's why Mint has been making their protractors based on these numbers. However, the vinyl engine article linked in the first response reports that the actual mounting distance on the JMW-9 is 222mm, not 223. I measured mine and it indeed appears that it is 222mm. This would also comport with what VPI told me in response to my email, i.e., that the JMW-9 has the same geometry as the Rega RB-300, which has the mounting distance of 222mm. If so, the protractor for the JMW-9 tonearm should be made based on the mounting distance of 222mm and the effective length of 239.5mm under the Baerwald algorithm, and NOT 223mm and 240mm, respectively.
That is why I wonder if the JMW-9 protractors are actually correct. Because VPI refuses to reveal the actual measurements, it is difficult to determine exactly what numbers the protractors for VPI tonearms should be made based on. That's why I wanted to try a set-up with both to compare.
Hope this clarifies my previous post.