The arbors I have out of music wire have a 3mm diameter. They do not seem to fit into the 623RS bearings that well. Maybe I could get them in by hammering them in, but they are probably a fraction of a millimetre too big. Should I be:
Filing their ends to fit?
Forcing them in? (I am quite concerned this would damage the bearings).
It's hard to tell from the videos what's happening.