[DampRobot]

We did a project a while back with a planetary gearbox for the drivetrain. For a ring gear, we used the ring gear from a GEM planetary from AndyMark. It's 20 DP if I remember correctly.

I'd go ahead and do the actual stress calculations for yourself (and you seem to be interested in doing that anyway), but I'd be inclined to believe 24 DP should be fine. Whether or not a specific gear will work for you depends on face width, the actual tooth profile, the material, and of course the application. You need to develop a good, conservative idea of the stresses that these gears will experience before asking questions about whether a specific gear is appropriate.

I'd guess that the gears for VersaPlanetaries are metric, and I'm fairly certain they have addendum modifications. You might have some luck contacting JVN or Paul Copioli on CD or via the VP site, but there's always the possibility that they won't release specifics on the technical details of the VersaPlanetary gears. If you just want a rough approximation of the pitch, count the number of teeth on a given pinion and measure the approximate pitch diameter with calipers or a ruler. Toothcount over approximate diameter would give you an approximation of the DP.