Strategy for setting up a floating tune-o-matic bridge for the first time?

[JazzyRandy]

When I first went to restring my Ibanez AF95 I had no idea the bridge was floating and only secured by string tension. So it came as a great surprise when it fell right off! So I need to figure out where it needs to go have appropriate intonation. While I'm at it, I thought it would be fun to start the intonation process from scratch, since I don't know how well it was intonated to begin with (I bought the guitar used off of Reverb). Which makes me wonder... where do I begin?

Does anyone have any good or proven strategies? The best one I can think of is to...

• Start with all the saddles at the mid point of the tune-o-matic bridge,
• Place the bridge so the low E saddle is the distance of the scale length from the nut
• Verify neck relief
• Verify action
• Check intonation of the low E, moving the bridge up or down to compensate
• Set the intonation of the remaining strings by adjusting the saddle position on the bridge
• If any of the saddles hit the extreme limit of adjustability, move the bridge in that direction until that string is intonated
• If the bridge did need to get moved, go back and redo the intonation of previously checked strings by adjusting the saddle position of those strings

Is that the way? Is there a better way to avoid the iterative steps required if the bridge needs to be moved throughout the process?

[sgosnell]

That's pretty much it. On many archtops the bridge will be more or less even with the points of the f holes, but not always. Measuring the scale length is a good starting point, and more accurate. The only thing I would add is to initially position the bridge so that both the E strings intonate well, then deal with the other strings. That should insure that the bridge doesn't need to be moved again. If you run out of adjustment room, the saddle can possibly be reversed, but something is probably wrong, because it should not take that much movement to get proper intonation with a standard set of strings at standard tuning. The initial intonation of the E strings doesn't have to be perfect, just reasonably close. One thing that makes things much easier is a strobe tuner. Without that, getting the intonation correct for every string, or indeed any string, is difficult if even possible. A cheap clip-on tuner isn't accurate enough. It's possible to do it by ear if your ear is good enough, but I prefer a strobe tuner. The TC Electronics UniTune or PolyTune will do the job, but I personally prefer the Peterson Stroboclip. I have both, because I found the TC on sale for a price I couldn't resist.

[2bornot2bop]

Iterative? Hold on, I’ve got to look that up.

[rpjazzguitar]

I've always heard that you have to put on new strings first.

I'd also suggest checking whether the bridge wobbles on the posts, if it's constructed that way. If it wobbles, it may be a good idea to shim it until it doesn't. I don't know if this applies to the kind of bridge you have, but it certainly applied to the tuneamatic on my Comins GCS-1, and the shimming (with tape) helped.

[John A.]

IME, the bridge sometimes leaves a mark or shadow in the finish, and I’ve been able to line up the bridge with that as a starting point for intonation.

[sgosnell]

Yes, sometimes the bridge marks the top, either through pressure or scuffing, and that's the place to start. But that's not always the case. I use whatever information I can get.

[burchyk]

You've got it.

In addition, watch out for sideways positioning. I usually align it by checking the E/e string distance to the edge of the fretboard.

Floating bridges often have posts that would move a bit back and forth. Check the angle after tuning up and try to put it at 90 degrees to the base and the body.

Recently got a locking Faber TOM. Pretty cool idea, it has a counter nut on top that locks the TOM with the posts, otherwise most of them can shift a bit which can affect tuning stability and vibration transfer.