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  #1  
Old 03-20-2019, 12:50 PM
AcousticDreams AcousticDreams is offline
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Default Luthiers!!=saddle height ratios?

I have been making my own saddles for a couple of years now and really enjoying it. I have Mituyo non digital Calipers for replicating accurate measurements on my saddles.
What is exact ratio of Saddle Height, to String Height at the 12ft? I know that it is not a one to one ratio, as the string travels across the fret board to the saddle via a right triagle.
As an example; if I shave down 20 thousands on the saddle, how much will it lower the string height at the 12th fret?
I am working a little bit differently. I sand the top of the saddle so I an adjust Individual string heights. Much like you would with an electric guitar. ( after sanding the top, I have to thin the ridge, as I have now thickened it up a tiny bit.
Worked on a saddle the other day, and had to loosen the strings Six times to get the heights I wanted. Too much work! Knowing the exact ratio would save lots of time.
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Old 03-20-2019, 01:00 PM
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Quote:
Originally Posted by Knives&Guitars View Post
I have been making my own saddles for a couple of years now and really enjoying it. I have Mituyo non digital Calipers for replicating accurate measurements on my saddles.
What is exact ratio of Saddle Height, to String Height at the 12ft? I know that it is not a one to one ratio, as the string travels across the fret board to the saddle via a right triagle.
As an example; if I shave down 20 thousands on the saddle, how much will it lower the string height at the 12th fret?
I am working a little bit differently. I sand the top of the saddle so I an adjust Individual string heights. Much like you would with an electric guitar. ( after sanding the top, I have to thin the ridge, as I have now thickened it up a tiny bit.
Worked on a saddle the other day, and had to loosen the strings Six times to get the heights I wanted. Too much work! Knowing the exact ratio would save lots of time.
It’s exactly 2:1. Lower it 0.020” at the saddle and you reduce the action by 0.010” at the 12th fret.
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Old 03-20-2019, 01:01 PM
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String height at the 12th fret will reduce by exactly half the amount you lower the saddle.

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Old 03-20-2019, 01:02 PM
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It's 1/2, so shaving 0.020" off the saddle will reduce 12th fret action by 0.010".
Or, put the other way, however much you want to reduce 12th fret action by, you need to take double that off the saddle.
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Old 03-20-2019, 01:48 PM
Rodger Knox Rodger Knox is offline
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This may be a question that actually gets a consensus of opinion.
Fiirst four answers agree!
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Old 03-20-2019, 01:54 PM
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Nice that math is not subject to opinions, suppositions, rumors, habits, conventional wisdom, and traditions, ain't it?
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Old 03-20-2019, 01:59 PM
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It’s basically 2:1 for height relieved from saddle to height lowered off of 12th fret action. There’s some assumptions here: 1.) that your first fret action is minimal and 2.) that your fretboard is relatively flat.

Saddle height in general is a function of neck angle, bridge height, radius and string gauge.
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Old 03-20-2019, 02:08 PM
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For some of us this may be the first practical application for the geometry we learned in high school
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Old 03-20-2019, 02:09 PM
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Originally Posted by phavriluk View Post
Nice that math is not subject to opinions, suppositions, rumors, habits, conventional wisdom, and traditions, ain't it?
I wish that were true.

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Old 03-20-2019, 03:22 PM
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It is extremely important that all of the strings are on a precise line perpendicular to their length at the bridge. Otherwise a skilled player will have an unnecessarily hard time managing dynamics as they go from string to string. Once established, messing with relative string heights opens a can of worms. It is a much better idea to adjust height of the saddle as a whole.

More controversial than the 2 to 1 ratio, perhaps, but IMO as true.
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Old 03-20-2019, 04:11 PM
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Quote:
Originally Posted by Bruce Sexauer View Post
It is extremely important that all of the strings are on a precise line perpendicular to their length at the bridge. Otherwise a skilled player will have an unnecessarily hard time managing dynamics as they go from string to string. Once established, messing with relative string heights opens a can of worms. It is a much better idea to adjust height of the saddle as a whole.

More controversial than the 2 to 1 ratio, perhaps, but IMO as true.
I am not following your comment. Many saddles have a radius to reflect the radius of the fretboard.

For example
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Old 03-20-2019, 04:54 PM
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For all intent purposes it is 2:1+ a tad. What you have not factored in is the compensation which varies from player to player, based on each player’s unique string attack. A compensation of .100” is only a starting point and not set in stone. You are assuming that the scale length is 2X the nut to the 12th fret distance, which it’s not. It’s 2X the nut to 12th fret PLUS ~.100” which is only measured at the little “e” string.

For example, a “scale length” of 25.5” with a compensation of .1” would actually measure 25.6” from the nut to the center of the saddle at the little e. In reality it’s still called a 25.5” scale length.

I agree with Bruce that it is more common to remove material from the bottom of the saddle. It will save you time because once the top of the saddle is accurately compensated then you only have to remove material from the saddle’s bottom to set the action at the 12th. Otherwise removing material from the top, you may be repeating unnecessary steps?
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Old 03-20-2019, 05:40 PM
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Quote:
Originally Posted by rick-slo View Post
I am not following your comment. Many saddles have a radius to reflect the radius of the fretboard.
Did somebody say "straight" line?
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Old 03-20-2019, 05:46 PM
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Quote:
Originally Posted by Bruce Sexauer View Post
Did somebody say "straight" line?

They probably meant straight from saddle to 12th fret (?)

Or they build classicals (??)

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Old 03-20-2019, 06:06 PM
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Quote:
Originally Posted by Bruce Sexauer View Post
Did somebody say "straight" line?
Not a helpful comment.

My interpretation of the earlier comment of "Otherwise a skilled player will have an unnecessarily hard time managing dynamics as they go from string to string." is that a ruler laid across the six strings should touch each string at the same time (ruler flat). Of course that would not be the case with a radiused saddle.
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