On Sat, 26 Jul 2003 18:59:27 GMT, "Alex" wrote:

My question is about life expectancy on following linear slide setup:

Two parallel 5/16 rods and a slide that uses a pair of small plain
ball bearings(5mmx12mmx5mm) on the same
axel with the spacer between them instead of a each single grooved roller.
The
ball bearings will roll on the both side of the rod since the spacer will be
shorter than rod diameter.

It's a preloaded design with preload no more than 10-15lb.
Speed is 1 foot/sec.
It's manually driven device and "high mileage" is not expected.

I understand that radial BB are not made this kind of thrust load but since
it's a relatively light load I think that it should work fine.

What do you think? Is it acceptable compromise?




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.