Mark, I ran your numbers in PLOP. I got P-V 3.27e-05, RMS 7.26e-06 I have understood that the maximum deviations allowable for a good scope are: P-V 1.7e-05 RMS 4.3e-06 Based on these values a 9 point support is not good enough for a first rate mirror. This might be good enough for low power photography or observing though. I would make an 18 point support. Steve