[maxthomas]

Hoping to get some engineering feedback here... I'm designing a rotary axis with an 8" open bore, and considering bearing options. I'm curious if anyone has tried a V groove bearing arrangement with a circular rail running in the middle, or if there's any reason that wouldn't work. See attached for a mockup of the concept.

This isn't for a CNC machine, there will be a video camera mounted to the rail. Maximum load I'm planning for is 20lbs. The whole mechanism will move, so it needs to handle the load in any orientation.

I'd have the rail made of steel to minimize wear. The top 2 bearings would be on eccentric bushings to preload the rail and eliminate play.

I realize there are things like thin-section bearings that would be a cleaner solution, but even the knockoffs are $500+ at this size, a little steep for this project. A cheap alternative is the VXB.com lazy susan bearings, but I've ordered some samples and I'm not crazy about the quality.

Is there any reason this shouldn't work? Some reason the rail would be especially difficult to machine? I've been searching around and can't find any examples of this, so I feel like I may be missing something obvious.

Thanks for any advice,
Max

[ger21]

It should work fine.

[RICHARD ZASTROW]

It would be even less expensive with (2) stationary non-eccentric and (1) adjustable eccentric bearings. Assuming of course they're sized properly. That way the center of the assembly shoul not move as it might by adjusting the (2) eccentrics.

Dick Z

[maxthomas]

Thanks guys. I like the 3-point bearing idea, I'll try that out. Appreciate the feedback.

Max