What dimension for bridge

[Redbloke1956]

Hi all, I have inserted this in a previous post but am posting it again as a standalone.
I am about to carry out a repair to the bridge on my first build and realise that an “accurate” figure cannot be stated without figures that I cannot yet measure, but I am looking for a ballpark/Starting point for the height relationship between a straightedge placed on the frets and the top of the Bridge as per this photo

[RodC]

I think that you want to identify what action height you want above your 12 fret. If you then double it you will get the ideal height of the saddle. Then you just have to work out the bridge and saddle combo.

RodC

[kiwigeo]

Stick in a packer on top of 12th fret with thickness equal to final action heights for strings. Measure height of straight edge above top of bridge at saddle position and then see how much you have for bridge to top saddle height.

[Redbloke1956]

Martin, thanks for the reply mate, now don’t laugh....what sort of figure is the final action height....know virtually nothing about guitars yet, I don’t even play yet...this is a birthday gift‍♂️‍♂️‍♂️‍♂️ for my brother

[kiwigeo]

Exact action setting will depend on a few factors including personal choice but here's a rough guide. Trevor has some figures in his books...my copies re stashed away at present so cant access them. https://www.stewmac.com/video-and-ideas ... gauge.html

From memory on my last Gore build the height of string above bridge at saddle location was around 4mm. That's the amount of saddle that will be protruding above top of bridge. You can tape a 4mm drill bit to top of bridge to simulate saddle during set up.

Martin, thanks for the reply mate, now don’t laugh....what sort of figure is the final action height....know virtually nothing about guitars yet, I don’t even play yet...this is a birthday gift‍♂️‍♂️‍♂️‍♂️ for my brother

[Mark McLean]

When string tension goes on it will pull the neck forward a bit, and the top will be pulled up a bit, so the position of that straightedge will drop some. Trent is right in saying that the ideal situation is when the straightedge just kisses the top of the bridge. Then the neck angle is correct and the string action (height above the plane of the frets) is determined entirely by the height of the saddle. In that circumstance a saddle protruding 5mm above the top of the bridge will give you a string action at the 12th fret of 2.5mm, which is pretty ideal for most circumstances. But IMHO that whole scenario is referring to an instrument that is strung and tuned up.

Given that you are looking at it now without string tension I think it might be pretty good as is. But you never know until you string it up and let it all settle for a day or two. But others with more experience than me might be able to predict if it is overset at this stage.