Mounting threaded rod

[barum]

Hello,
I used small bearings on each end and screws to hold. Problem is that low quality of hex nut that holds bearing in place. It bends rod a little when bearing is laid in holder. That brakes rotation and produces loud noise in puller nut.

How to mount those bearing on rod to get smooth motion. Do I have to machine one side of hex that contacts to bearing or use plastic inserts or what?


Bojan