[Dillon Carey]

Brando,
We used needle thrust bearings to handle the thrust load. the delrin ring went around the bottom of the module, which had an aluminum ring on it. This ring was there only for extreme load situations. Like Al said without bottom support things tend to bind under extreme load.

But I do believe with the correct bearing and support you can nearly remove the lower bearing without much increased turning friction under load. Ex: in a pushing match, if your module is supported enough to have almost no binding until your traction brakes then you should be able to get away without supporting the bottom of the module.