I oil all raw metal.
It keeps ALL FAST ANGLE needle tips rust free and that keeps them smooth which won't wear out plastic. Even tiny amounts are abrasive.
Use light plastic safe oil. (mobile 1 is one...read containers)
Sparingly, soak excess off with rag/PT. Ideally set on a rag for hours/overnight then wipe wheels again, then run.
Oil raw metal like you would a rifle.
Edit in Bold Goofle Auto Spellwreck