pic: Planetary...Wheel?

[Kevin Sevcik]

I'm not an expert on gears by any means, but I think just spreading the load across the gears won't help that much. Gears are meant to operated at fixed distances on fixed shafts. 25 pounds of force pushing the gears into each other isn't going to make them happy. Even if you could get it down to 5 pounds, you'd still lose a lot of efficiency. I think your best bet is to figure some way to get a bearing supporting the wheel so you're not using the gears as a bearing sort of surface. This would help with the side loads too.

I'm thinking a big thin section ball bearing that goes around your array of bearings there and slips inside a rim on the wheel. At that diameter a brass bushing might work as well.