life expectancy with thrust load on radial bearing

Try it and see. An alternate idea would be to use thrust bearings to take the side load. There is a web site with a guy making and selling what he calls a Home Brew Linear Bearing. Check it out:

Alex, Consider that the bearing you are using has a speed rating of probably

Gary H. Lucas

Y ears ago, and maybe still, Sears radial arm saws used small diameter rods along each side of the overarm - and used bearings in which the outer race was concave on the od - then the bearing was adjusted to proper force against the rod and rolled along front to back along the rod just fine. It also supported the weight of the motor, blade, guard and the forces of cutting. Worked well, so maybe one of those types of ball bearings would work in your instance. Ken.

While this is true for plaster molds, he is just dipping them to give them a thin layer for loose sand casting (Lost Foam). Also, his mix has sand in it. (drywall texture).