4,5mm BB bearing how to - SketchUp

I tried making some berrings using 4,5mm airgun BB's.

I included a video of how I made the bearing: https://youtu.be/ymC9LT3nthI
It works pretty well.

For 4,5mm BB's you need to make a 5mm channel. My first try was 4,7mm and the balls are so tight that it is as stiff as a rock.

I know the barrings from china cost less than the time I put in, but this seems like a quick way to make costom bearrings on the fly. You could for example make a square mounting plate with an integrated custom