Action using a gradient?
Posted: Tue Jun 05, 2012 1:44 pm
Don't know what to name this thread but came across this little resource while looking at how to sort out some low E buzz. Basically the action moves progressively from 1mm to 2.75mm across the six strings, low E being the highest action. Low E is still easy to play with no buzz, top strings are nice and low for the meedlys. Feels good man.
http://fingerlakesguitarrepair.com/adju ... r-saddles/
http://fingerlakesguitarrepair.com/adju ... r-saddles/
How to Derive Adjusting Measurements
You must first find the “center lineâ€�, an imaginary line that goes through the center of each string as they get progressively higher off the fretboard from the 1st string to the 6th string. Finding the center line begins with determining the center of the e strings. I’ll use “extra lowâ€� action with 10′s as an example. Subtract the measurement from the top of the strings (1mm and 2.75mm) by half the diameter of the given string: 1st: .875, 6th: 2.165
Now that you have the lowest and highest points of the center line you must determine the interval by which each string measurement is increased from the previous. 2.165mm – .875mm = 1.29mm divided by 5 (the number of steps up from the 1st string to 6th string) = .258mm This is the interval by which each string center will increase above the previous.
Now add .258mm to .875mm (the center of the high e string) to get the center of the 2nd string = 1.133. Continue adding .258mm to the previous string measurement until you have the centerline measurement for each string:
1st: .875
2nd: 1.133
3rd: 1.391
4th: 1.649
5th: 1.907
6th: 2.165
The last step is to find the measurement to the top of each string that you’ll be making. Add half the diameter of each string to it’s center line measurement: .875mm + .125mm= 1mm (final adjustment measurement to the top of the 1st string).
1st: 1mm
2nd: 1.298mm
3rd: 1.606mm
4th: 1.979mm
5th: 2.362mm
6th: 2.75mm
These are the final adjustment measurements (measured from the top of the 12th fret to the top of the strings) for each string given that 10′s and “extra lowâ€� action are desired.
To make things a little more accurate/consistent, I place the ruler against the side of the string opposite to my eyes and tilt the upper bout of the guitar away from my body until I can just barely see the point of contact between the top of the 12th fret and the bottom of the ruler.