Idler holddown roller bearing

[Gerald D]

Copied from elsewhere:

I am sure a narrower bearing at 8mm would also work 100%

The 6304 bearing was selected because:

- It has a big difference between inside and outside diameters so that it can fill the space used by the rack on the other side of the gantry, before the shaft M130224 touches the y-car.

- It is cheap ($10) and easy to find


I don't have my bearing catalogue here at home, but I don't think there is a common bearing with a narrower face that will do the job - if there was, I would probably have selected it.

[Gerald D]

Copied from elsewhere:

First get a suitable sealed ball bearing that will roll under the angle iron of the rail. It is supposed to be a 6304.2RSR, but that is not critical. A V-Roller is the wrong thing in this application, to roll under the flat part of the rail. Two things to check when finding the right bearing:
1. It must be narrow enough to miss the screw heads you used for the cable chain brackets where they are screwed into the side of the gantry. (Or you need to move those screws lower down and shorten the brackets).
2. The outer diameter must be big enough (and the ID small enough) so that the stubshaft will miss the underside of the Y-car. It has been known to grind notches in the shaft and/or y-car to get the clearance.

Then you have the smaller problem of the screws touching the plastic cable chain. You could countersink the screws, or you can dump the screws and weld it together. You could even cut away the bottom section of the bearing support base plate before welding it together.

[Zouave]

Just an FYI, Fastenal has the 6304-2RS for $4.15 till the end of the month.