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  #1  
Old 05-10-2017, 06:26 AM
capohk capohk is offline
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Default Saddle compensation measurement

I'm just measuring up for fitting the saddle on my latest build - it's a Gibson 24.75 scale length and the best I can find for compensation is +1/16" at the high E and +5/32" at the low E

Does that sound about right?

Last edited by capohk; 05-10-2017 at 07:54 AM.
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Old 05-10-2017, 07:04 AM
John Arnold John Arnold is offline
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1/8" is too much on the high E, unless you are measuring to the center of the slot. I use 0.075" on the high E, measured to the front edge of the slot. Since the high E is normally compensated to the front edge, it makes sense to me to use the actual measurement that you want for the string length.
I never measure the compensation at the 6th string, since I use a standard saddle angle.
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Old 05-10-2017, 07:57 AM
capohk capohk is offline
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Hi John, sorry, I meant 1/16 and 5/32 - have amended in the original post. Shorter scale requires more compensation I think so is your .075" specific to the 24/75 scale length?

Also, would you mind sharing what the 'standard' saddle angle you use is?

MTIA

Matt
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Old 05-10-2017, 09:40 AM
Halcyon/Tinker Halcyon/Tinker is offline
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The stew Mac fret calculator also gives actual string length for whatever scale length you put in. It works quite well and will certainly give you a place to start...
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Old 05-10-2017, 10:33 AM
redir redir is offline
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Yea you can figure out the angle from using the Stew Mac calculator. I use a 'standard angle' too. I honestly don't know what it is, I built a jig to cut saddles 25 years ago and use the same one today. What ever that angle is I just set the compensation back .1in to dead center of the saddle slot which is probably the same as Johns measurement to the front of the saddle for a standard saddle thickness of 1/8th - ish inch. So far that's been good enough for jsut about everyone.

I do this for all scale lengths BTW.
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Old 05-10-2017, 11:40 AM
John Arnold John Arnold is offline
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Quote:
Shorter scale requires more compensation
That has not been my experience. Higher action and heavier strings do require more compensation, but the 1/2" difference between short and long scale (2%) is IMHO not enough to change the required compensation measurably.
My saddle angle is the one Martin used on through slot belly bridges from 1934 until 1965. I believe it is 2 degrees.
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Old 05-11-2017, 12:34 AM
capohk capohk is offline
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Thanks to you all - I've been comparing some different approaches.

The Stew Mac fret calculator is very useful - it gives the string distance to the string break over the saddle. Taking the difference between the two compensated lengths over a string spacing of 2.25" gives an angle of approx 3 degrees

The measurements I found in my notes - 1/16 and 5/32 produce an angle over the same string spacing of approx 2.5 degrees.

I guess this is why Somogyi et al have preferred a much wider saddle...
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Old 05-11-2017, 09:00 AM
John Arnold John Arnold is offline
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No matter what angle you use, it is a compromise because the string lengths for best intonaton do not lie in a straight line. The 2 degree angle subtends the first and fourth strings, making the second, fifth and sixth sharp, and the third flat before saddle compensation. A 3 degree angle subtends the first and fifth strings (usually), making the second and sixth sharp and the third and fourth flat before saddle compensation. Steeper angles will tend to improve intonation on the second and sixth strings, while making the third, fourth and fifth more flat.
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Old 05-11-2017, 09:28 AM
charles Tauber charles Tauber is offline
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Quote:
Originally Posted by John Arnold View Post
No matter what angle you use, it is a compromise because the string lengths for best intonaton do not lie in a straight line.
And that's why a thicker saddle is used: to eliminate that, specific, compromise.
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Old 05-20-2017, 09:16 AM
mercy mercy is offline
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Would using the standard angle and moving the bridge back 1/32 avoid the "hacksaw" back and forth look typical of fully comp'd saddles?
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Old 05-20-2017, 10:02 AM
Earl49 Earl49 is offline
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Extra setback would help, but the stepped approach for each string is going to give the best result with the least compromise. Look at pics of the Stew Mac intonator for some more clues.
http://www.stewmac.com/Luthier_Tools...Intonator.html

Something like the Taylor wave compensated saddle takes a more aesthetic approach.
https://www.taylorguitars.com/taylor...ustic-6-string
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  #12  
Old 05-20-2017, 05:06 PM
John Arnold John Arnold is offline
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The stagger will always be there because there are plain strings and wound strings. The amount the string tightens when you press it down to the fret is determined by the core diameter on the wound strings. Since the core of the third string is smaller than the diameter of the plain second string, it requires less compensation. In other words, relocating a straight saddle will do nothing to eliminate the required stagger....it is a characteristic of the strings themselves.
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  #13  
Old 05-20-2017, 05:26 PM
mercy mercy is offline
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To be clear, I understand you need the 2-3% angle but Im questioning the filing forward and backward for individual string comp. Typically that will be all the way forward for the e string and all the way back for the b, all the way forward for the g string and all the way back for the E string with the remainder in between the E and g.
Im proposing that with the angle all you need to do is move the bridge back 1/32 from theoretical.
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Old 05-20-2017, 06:30 PM
redir redir is offline
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Quote:
Originally Posted by mercy View Post
To be clear, I understand you need the 2-3% angle but Im questioning the filing forward and backward for individual string comp. Typically that will be all the way forward for the e string and all the way back for the b, all the way forward for the g string and all the way back for the E string with the remainder in between the E and g.
Im proposing that with the angle all you need to do is move the bridge back 1/32 from theoretical.
That's a typical filing pattern that you see on many guitars. It's really just a best management practice if ya want to look at it that way. But 1/32 is WAY to short for proper string length compensation.
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  #15  
Old 05-20-2017, 09:57 PM
charles Tauber charles Tauber is offline
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Quote:
Originally Posted by mercy View Post
Im proposing that with the angle all you need to do is move the bridge back 1/32 from theoretical.
Reread what John wrote.

If you want the instrument to play as in-tune as possible, there will always be a staggering of actual vibrating string length to accommodate the specifics of each string.

Looked at another way, the angling of the saddle just reduces the thickness of saddle material necessary to set each vibrating sting length were it should be for best intonation. Some guitar makers, me included, do not angle the saddle at all and simply use a thicker saddle.
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