Hi,

I have looked around and found that making my own linear railings seems to be the best route for me.

I've looked at EBay and there are a large number of different bearings. The most popular seem to be the ABEC 3-7. Does anyone know why I would need the ABEC 7 as opposed to the ABEC 3?

Or are bearings just bearings in this applications, as RPM isn't really an issue and they will be adjustable, so I don't need chrome hardening (or do I)

The design I'm thinking off is slightly different to this one.