Jamie M fired this volley in news:k459oh$ol$1
@speranza.aioe.org:

Or an angular contact bearing and a
roller bearing maybe. Also what is the best mechanism to apply
the axial preloading?


Angular contact with a pre-loading nut.

But don't count on merchant stock tubing being oversized enough to fit
properly. It might be. It might also be a few thou. small.

Buy a piece of "hollow rod" stock suitably oversized, and turn it to fit
the bearings. Then you can also shoulder the piece so the bearings have
something to press against in pre-load.

LLoyd