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An electric bridge question.
http://mowrystrings.luthiersforum.com/forum/viewtopic.php?f=10123&t=36078		 Page 1 of 1
Author:  Harold_Donn [ Mon Apr 09, 2012 4:22 pm ]
Post subject:  An electric bridge question.
On an electric guitar bridge there are several adjustments.

You can move the string up and down to raise and lower the action and you can move it forward and backwards to lengthen or shorten the string, right?

I'm new at building. I've only done ukuleles before and they have a fixed bridge, or at least the one's I've made have :-)

I thought I read somewhere that you can lengthen and shorten the strings in order to compensate for the small bend in the string that comes from fretting a note. Not bending a note but just fretting it. The bridges on electric guitars are set on an angle because of this right? the base notes are longer and the treble notes shorter. That's where you get that angle from that you usually see bridges set at.

Where ever I read this, and I wish I could remember where, said that the difference in pitch isn't audible to the human ear. So how do you know what to adjust the string length to?

I've searched LMI and Stewmac for some kind of electric meter but I can't seem to find anything. I haven't set the bridge or the neck yet because I want to place the bridge in the spot that will give me the best use of these adjustments. Should I adjust all the saddles on the bridge to the middle and use the measurement from the nut to that point for my scale? Or is there a better way to do this?

Thanks.
Author:  StevenWheeler [ Mon Apr 09, 2012 5:37 pm ]
Post subject:  Re: An electric bridge question.
Hi Harold,

Follow this link to the StewMac fret scale calculator. http://www.stewmac.com/FretCalculator. Put in the required information and hit the calculate button. Scroll down the resulting page and find your bridge. Position your bridge at that measurement and you'll have plenty of room to move the saddles for compensation. To set your compensation get a good tuner, one that reads in cents if you can. Tune the open string and then play the string fretted at the twelfth. If the tuner reads sharp, lengthen the scale (move the saddle back) if it reads flat shorten the scale length. You will have to retune the open string each time you change the saddle position. Do that for all six strings and your done.

Steve
Author:  B. Howard [ Mon Apr 09, 2012 6:19 pm ]
Post subject:  Re: An electric bridge question.
The adjustment you are referring to is called intonation. I use a Peterson strobe tuner to set that. They have some good articles on their site under the resources tab that explain the concept and the adjustment well.

http://www.petersontuners.com/

You may also use certain smart phone apps to do the same thing, I happen to like a dedicated tuner.
Author:  Stuart Gort [ Mon Apr 09, 2012 7:30 pm ]
Post subject:  Re: An electric bridge question.
The bending string thing is generally referred to as stretch compensation.

http://windworld.com/features/tools-res ... calculator

I use that calclator for my frets and then draw the grooves with cad and cut the fret grooves on a cnc machine....the intonnation is dead on accurate using stretch compensation with .009 - .042" strings.
Author:  alan stassforth [ Mon Apr 09, 2012 8:02 pm ]
Post subject:  Re: An electric bridge question.
I don't build regular electrics anymore,
but lap steels only.
The bridges on laps are straight across.
What I used to do was figure out the string length compensated,
on the bass and treble strings,
(you could use the Stew Mac chart for that)
Then move the saddles all the way back and forth with the screws,
and set it where it will work.
Most electric bridges have a lot of latitude that way.
You shouldn't have to angle the bridge,
to my recollection.
What I think you are talking about with "bending",
is what's called "relief" in the fretboard,
which is a slight bow in the fretboard,
so when you fret low on the neck, the action can be lower, and the strings won't buzz.
If you have a good ear,
you don't need a tuner to intonate.
A tuner is nice though.
Author:  Harold_Donn [ Tue Apr 10, 2012 1:26 pm ]
Post subject:  Re: An electric bridge question.
Thanks guys! That solves my problem...
Author:  Mustang_jt [ Tue Apr 10, 2012 6:15 pm ]
Post subject:  Re: An electric bridge question.
One of the best resources for this is The Guitar Players Repair Guide by Dan Erlewine http://www.amazon.com/The-Guitar-Player-Repair-Guide/dp/0879309210/ref=sr_1_1?ie=UTF8&qid=1334099435&sr=8-1

The section on set ups is fantastic. Intonation is about the last thing you do in a set up because adjusting string height or neck bow will effect the intonation. There is also a lot of other great information in the book including typical setups for factory guitars and a lot of famous guitarists.

-John
Author:  Brett L Faust [ Mon Apr 16, 2012 7:49 pm ]
Post subject:  Re: An electric bridge question.
If you are an iphone user you should buy the Petersen Strobosoft app.
It is the best money I have ever spent on a tuner,cheap,extremely accurate and very portable.
So good that many folks are selling the old fashioned tuners in favor of the new one that comes with a bunch of other stuff like a phone etc.....
Author:  B. Howard [ Thu Apr 19, 2012 4:59 pm ]
Post subject:  Re: An electric bridge question.
My son uses an app on his Andriod called G-string. It's just as accurate as my Peterson.
Author:  Freeman [ Fri Apr 20, 2012 10:01 am ]
Post subject:  Re: An electric bridge question.
I also use the Peterson flip strobe tuner, but my little Korg will blink its sharp light. If you have good ears you can tell the difference between the 12th fret harmonic and the fretted 12th fret note, but for actually adjusting the saddles I use the Stroboflip.

There was a good article in American Lutherie a year or so ago going into the math of calculating the amount of sharpening - one of the factors is the diameter of the core (not the overall diameter of a wound string) I'm most familiar with acoustic guitars - the B string is larger in diameter than the core of the wound G which means that it needs more compensation - that is why acoustic saddles have the little notch for the B string.

Since I have drifted to acoustics, I also learned a really cool trick for compensating them. You get the saddle slot "close" with some rules of thumb, then as you do the setup leave the top flat while setting relief, nut slots and basic action. The last step is to put a small piece of wire on the top of the saddle under the string (a piece of B string works well) and move it back and forth until the fretted not plays in tune. Mark each side of the wire and make the break point there. I've used this on 12 strings and the saddle comes out looking like a rip saw blade, but the guitar plays in tune.

Much easier on an electric
Author:  alan stassforth [ Sat Apr 21, 2012 10:32 am ]
Post subject:  Re: An electric bridge question.
Brilliant idea with the string under the string, Freeman!
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