Making a steady rest

[PixMan]

I don't know if you've spent much time thinking about the final position of the tubes and how that relates to where the bearing supports will be extended to for the bulk of the applications.

The whole assembly may be capable of accepting 300 mm or more in size, but I wouldn't be putting too much weight on 10mm wide standard duty bearings. If you were to push the tubes in a little more and limit diameter to 200 or 250mm, the bearing carriers would have better support for the more common applications of long, small-diameter work.

Just thinking, probably too much.