Re: Ibanez S420. bridge post wobble in the ZR trem, fix?
I know there isn't any original stud for ZR trem with set screw... All the anchor screws wobble if they aren't locked. Even thou FR studs wobble less for some reason but they're aren't locking. So they will wobble, but Ibanez locking studs won't =)
For a Knife trem the locking studs makes a big difference. But for the ZR perhaps it would make a bit difference but Ibanez settled it would be fine without.
So just go on with what you have
if you really want it to be locking...
Put the posts in a lathe and drill and tap them