p60 gearboxes

how does the outside ring gear secure to the plates on a p60 gearbox? Is is the same as the older planetary boxes where there are through bolts? and finally could anyone tell me the outside diameter of the ring gear?
Thanks

Funny you should ask. . .

Lately, I have been putting a lot of time into finding ways to make the P60 gearbox lighter, and currently I have a version that uses HDPE (which has a density less than water!) to replace the front and back plates. I have also turned the 'high speed/low torque' end of the ringgear down, and am in the process of testing an aluminum driveshaft (this one may not work, but I could do titanium). Of course I plan on using only two screws to hold it together, and I am considering milling some material off the carrier plates. I hope to trim 2-to-4 ounces. That's freeing up nearly a half pound on a two motor bot. I figure this be will tough enough for 15lb. drive setups where the gearbox connects to the wheels through belts--I do not think it will withstand battle if the wheel is on the gearbox shaft.

Back on topic--The ringgear is not held all that well--there are four roll pins driven into the front plate that sort of pinch two flat parts on the outside of the front/output end of the ringgear. I am of the opinion that most of the system is way overdesigned, but this one part is pretty flawed. For the new frontplate, I'm just adding a triangle of material where the rollpins go, and it seems to be working very well. I hope to do a full drive test in the next week or so.