Rotating Ballnut - design ideas

[Jonathan]

The bearing I used is a 3208 double row angular contact.

Almost the same as I drew in post #7 then.

Normal bearings, which includes double row ones, aren't really suited to applications with lateral loads.

Yes, however I looked up on the SKF site before using those and is say that the bearings I chose for the initial design are OK for half the radial load rating in the axial direction. That's 5100N, which is far higher than I will get on the router - unless I crash it, and the force is shared over 4 bearings so my thinking is that that might be the way to go as they're so cheap and, as you say, I can either replace with angular or the same if they wear out. I wouldn't be able to fit double row in though.

Is there a reason why you have not mentioned tapered roller bearings? They would fit well.