# Bridge placement - how close is too close?



## Nick Burman (Aug 17, 2011)

It's come time to route the neck pocket on my semi-hollow guitar. I have a 4 1/2" square block between the top and back for the bridge, but I want to make sure I'm leaving enough wood to secure the bridge properly. 
How much wood, ideally, should there be in front of a tune-o-matic bridge? It looks like I have a good 15mm. Can I get away with less?


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## Nick Burman (Aug 17, 2011)

Uh oh. If I don't get help, one guitar is dangerously close to disaster.


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## shoretyus (Jan 6, 2007)




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## Nick Burman (Aug 17, 2011)

Thanks pal. That looks like only 5/8". You made my day.


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## keeperofthegood (Apr 30, 2008)

I just had a look with my caliper at two of mine. One was 12mm and the other 15mm.


EDIT: should say that was to the routing, the humbucker body is another 5 or so mm farther up.


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## Nick Burman (Aug 17, 2011)

Gotcha. Thanks. I wonder if anyone with a physics background can shed light on the sass points in a guitar and where strengthening is needed?


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## Lil'Demon (May 3, 2011)

"How much wood, ideally, should there be in front of a tune-o-matic bridge? It looks like I have a good 15mm. Can I get away with less?"

I don't know what scale length the instruments' neck is, but this is not how you measure for bridge placement. Take your scale length, measure that from the inner edge of the nut to wherever it ends up on the body. (With the neck placed where it will be installed.) Set the contact edge of the bridge saddles at their exact center adjustment on the bridge. Align the saddle contact point with the end of the scale length measurement. this is where the bridge should be placed. If your scale length is say 24 3/4 like a Gibson etc, then you can go ahead and measure from the inner edge of the nut to the center of the bridge posts on a Gibson or same scale guitar and translate these measurements. If it is a more unconventional scale length, compensation placement is a bit more complicated to figure out. Gibson bridges are angled to create a degree of fixed compensation because a tunematic does not have the same range of adjustment as say a fender type bridge that is mounted straight. Hope this helps. Remember measure six times, cut once.


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## shoretyus (Jan 6, 2007)

Nick Burman said:


> Gotcha. Thanks. I wonder if anyone with a physics background can shed light on the sass points in a guitar and where strengthening is needed?


Not sure what you mean by sass points. The the pins are placed at the center point of the scale length with high side being 1/8" forward. That is what I remember for the wraparound tail pice. I think it's the same for the tune -o- matic. 

How much wood... there isn't much on that guitar ..I left a small block for the pins and pu's. But it's purpleheart= heavy so I routed away as much wood as I could


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## Nick Burman (Aug 17, 2011)

Thanks Demon, I have the charts from StewMac showing specific measurements from the nut for different bridges . Once I measure from the nut I'm now wondering about how much lumber is left between the posts and the pickup cavity, or in this case the routered out hollow. 

Actually I have no idea what sass points are either. I have no idea why I typed that... I meant STRESS points ! Sorry about that.


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## keeperofthegood (Apr 30, 2008)

You know, every guitar has a 'flavour' to it. Makes have scale lengths. People treat them like magic mojo numbers but they are just numbers chosen and adheared to by the company that chose that particular number but you don't have to stick with it if you don't want to. Pickup positioning is the same. If you have a neck pickup just off the neck one two guitars, one with 20 and one with 24 fretts though both in 'neck' they would have a different tone because they are at different string positions. Maybe a good rule for you is to use your index finger. Lay it against your bridge and start the route from there  Seems close enough, and it would end up with a flavour inspired solely by you.

If you were to get some scrap plywood and build an experimental body, rout out a cavity from just off the bridge all the way open to the neck, put in two round stock rails, and clips on a pickup so that it could slide the pickup up and down within that route you could find a spot you personally like for the tone it picks up. Use that position for your good build. I think one maker out there once even had this as a feature, you could roboticaly reposition your pickup while playing. Been a few years, not sure now about that but I seem to recall such an animal.


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## shoretyus (Jan 6, 2007)

I am assuming that this is the walnut alder build?... I just looked at the cavities pic and that looks like there is lots.


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## Nick Burman (Aug 17, 2011)

Great idea. Westone had a bass in the '80s (The Rail) that used that concept. For testing pickups it would be very handy.


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## Nick Burman (Aug 17, 2011)

Yes it is. Phew- thanks for that  Of course, at this point it's a little late, but I could always modify the neck a tad. Anyway, it seems that my worries are for nought.


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