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How do you determine bridge placement? I know scale lenth plays a part in this. I have measured some of my guitars. The guitar i used has a tune-o-matic style bridge and a scale lenth of 24.75. I determined that by measuring from nut to 12 fret and multiplying that by two. Then i measured from the nut to the saddle on the high E string and got 24.75, but when i measured the low E string i got 25. So my question is at what point do you measure to? It would make sense based off my guitar to measure the high E, but i wonder if there is a rule of thumb here. Any advice would be appreciated.

Hi, Brad, You don't say what kind of bridge you want to place. Forgive me if I'm telling you things that you already know. Yes, the bridge placement is determined by scale length plus a factor called "compensation." You determine scale length by measuring accurately from the nut to the twelfth fret, and then doubling that length. Then you add the compensation to the measured scale length.
So the imprecise answer to your question is "locate your bridge saddle at your scale length, plus a little." If you're working with a floating bridge, it's pretty easy. You just put the bridge at scale length and then slide it back a little toward the tailpiece until the notes at the twelfth fret are an octave higher than the same strings played open. You can measure this with an inexpensive digital tuner. Obviously, with fixed bridges (glued on, pinned, studded, etc.) you need to get them very close to perfect when you mount them. String gauges complicate things, because heavier strings require a little more compensation. There are several articles online that will help explain this and provide tips for locating your bridge saddle.

http://www.lutherie.net/saddle_angle.html

This next one is more technical, but once on the site, there are several more articles:
http://www.doolinguitars.com/intonation ... tion4.html

This one is a little over simplified:
http://buildyourguitar.com/resources/tips/abridge.htm

Look at "string gauge and compensation here:
http://homepage.ntlworld.com/coleman005/intonati.htm

This explains scale length and string gauge well:
http://www.stewmac.com/freeinfo/a-scalelength

And this free fret calculator will also help you locate a bridge:
http://www.stewmac.com/FretCalculator

After you read up a bit, come back and restate your question more specifically (bridge type, string gauges, high or low action, etc.) and I'm sure some very knowledgable people will jump in and
explain this a lot better.

Patrick

I have used a Saddlematic with very good success for many years now.

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and home of BeauGuard©

I guess i should have said it is an electric guitar with a tune-o-matic style bridge, like a les paul.

Okay, Brad. That's a bridge mounted to studs, if I'm not mistaken. But I am still not sure of your problem. Are you asking a hypothetical question (in other words, how do they figure these things out?) Are you thinking of building one from scratch? Are you proposing to mount a new bridge?
Or are you just wondering how to set the intonation on your individual strings? If my last question applies, then you adjust the individual saddles forward or back, until the fretted note at fret # 12 on each string is precisely one octave higher than the open note on the same string. Again, you can use an inexpensive tuner to measure this. You can probably do it by ear. And if you know how to pluck out a "second partial" over the twelfth fret, just adjust your saddles until your second partial and the fretted note are precisely the same. I don't know how to tell you what a second partial is in one sentence. Or even a paragraph. Think "plucking harmonics". Touch a finger of your left hand to a string over the twelfth fret. Don't fret it. Just touch it. Simultaneously pick a note and remove your finger, without fretting the note. When you get a clear note, you've found the second partial. It'll ring like a bell. Lots of rock players (and jazz players, too) incorporate this technique into their bag of tricks while soloing.

C'mon you other guys. Most of you guys are better at this than I am. Help this man out.

Pat

Thanks for your continued help. i wish i knew more about this so i could give you the information you need the first time. Its a new build from scratch. It will be my second build that i have taken to completion. My first build was a bolt on neck, fender style and i got this wrong and had to modify the neck so it would play right. since this is a new build i will need to find where to put the bridge. it is a 24.75 scale lenth. I know i can measure from the nut, or 12th fret, to the bridge. I just dont know at what point on the bridge i measure too. I assume i measure to the saddle, but its just a guess. I have noticed that most tune-o-matic style bridges are slanted slightly. I also know that the scale lenth is just a rough number to get you in the ball park. So, how do i know where to put the bridge and angle it necessary before i drill my holes and string it up? I hope there is enough info this time, and i hope it made sense to somebody.

Hi, Brad, So...you are building a solid body, Les Paul style guitar from scratch....is that correct?
If so, I applaud you. But stop for a little while. Get some plans--you can find them on the net. Just Google up the term "Les Paul plans". You will find plenty. Order a set of plans. They won't cost much. Not nearly as much as another guitar that doesn't quite play in tune. Take the time to study the plans carefully. You don't need to build an exact replica, but you will get a lot of insights into your scale length/bridge placement question. Do that much first. Then either draw out your own design on a big sheet of craft paper (open up a big brown grocery store bag or two, and iron them flat), or draw your modifications right on the existing plan. You can modify the body shape, headstock, etc., to suit you creative instinct. You've got to have a point of reference. Be sure to draw a side profile, too, because with a true Les Paul style guitar, you will have to factor in an angle where the neck meets the body. This is because the arched top of the "Paul" will put the bridge at a higher point than your Fender copy. Thus, the neck will need to go away from the body at an angle.
Go get your hands on a Les Paul, or a copy, and look at it from the side. You will see what I mean.
Then, ask yourself, is this going to be a flat top sort of guitar (Fender-ish) or an arched top sort of guitar ( Les Paul-ish). In either case, you need a side view plan.

Thanks again, I did build a guitar from a set of custom plans, but i did not finish it. That guitar had a floyd rose on it. I was to the point of hardware installation when it got ruined by a bug spray company, but thats another story. I could have salvaged it but decided to take what i had learned and start fresh. I completely redesigned the plans and so far it has come out great, allot better than my last attempt. I had originally wanted to use a non trem version of a fender bridge, but i want to switch to a Gibson style. I will most likley need to put some angle on the neck but i dont think that will be a problem. Here are some pics so you can see where i am at. I am a 3rd generation furniture maker so the woodworking was easy, its the technical side of things i dont know as much about. I think i have this designed figured out except for the bridge placement, and other minor things.

Use the stewmac fret calcularor
http://www.stewmac.com/freeinfo/Frettin ... tcalc.html
choose electric guitar and it will output stud locations for a tunomatic bridge.
Make sure that you first measure the actual scale length(nut to centre of 12th fretX2) because the gibson 24.75 is nominal and varies.

So you measure to the post on a tun-o-matic bridge? I think that answered my question. The fret calculator said to measure to the center of the treble post, and add an 1/8 to the bass side. I know that the post on a tune-o-matic are in the center of the bridge and so are the saddles. On a different kind of bridge the mounting screws will be forward of the saddles. It doesn't make sense to me to use the forward mounting screws as a measuring point. Can anyone explaining why that it is, Obviously thats the way its done i just dont understand it.

I'm glad Jeff chimed in. I think your guitar looks great, Brad. But, as I don't know very much about solid body guitars, and since I only have a theoretical understanding of this sort of bridge, I'm going to let the other guys help you out from here.

Do check that Stew Mac fret calculator, and Jeff and I have advised. I think between that and your plans, you'll be in great shape.
Patrick

Thanks cphanna, and jeff for all your help. I think i have it figured out now. It still seems odd to measure to the forward most mounting screw or pivot point, but if thats what it is then thats what it is.

Because the larger strings go sharper than the trebles when played, that's why.
I assume you are wondering why the bridge isn't absolutely parallel to the nut, right?
For the intonation to remain true, that is why the bass side is moved back on the measurement.

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I've always adjusted the saddles to the center of the bridge,
figured the compensation,
then measured to the high point on the saddles.

actually i was wondering why you measure to the forward most mounting screw, it seems to me that you would just take the scale lenth to the middle of the saddles travel. It just seems an odd point to measure to.

The calculator just make adjustments to a convenient measuring and marking point
In this case for the tunomatic it's the mounting stud holes, since that is what you need to mark and drill.
For a telecaster or strat it's the screw holes.
If you just measured the scale length to the centre of saddle travel you would not have enough compensation available because the string length is always longer than the theoretical scale length.

Ok, so thats not a rule of thumb just a convenience number given to you by stew-mac? I can understand that. So let say im using a bridge they dont sell and need to come up with the measurement my self, how would i do that? I think i have everything i need to continue with this build, i am just wondering for future builds, plus im trying to learn as much a possible.

And again thanks for everybody help

i know this is an amature way of doing it, but:
for alignment, i fix the neck, install the nut, install both "e" tuners on the headstock, then "string" them with kite string, run the string back to the bridge and pull it taught, then move the bridge around so the "strings" line up over the fret board just right, then mark that as the "vertical" bridge position. if the nut and headstock is not ready, just tape the kite string down to the fingerboard at the nut position.
for "fore and aft" length, i go with the theoretical scale, ie 25". on an adjustable bridge, extend the high E saddle about 3/4ths of its forward range, and use that for the theoretical (25")scale length. figure that you will be generally moving the other saddles BACK from this point, as strings get heavier, and older, they need to be slightly longer than the theoretical scale length in order to be in tune.
on some of my strats, i have found that the low E saddle does not really come back far enough for correct intonation, at times....so thats definitely a concern to think about