Angle of strings behind bridge

finkdaddy

finkdaddy

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On my first two builds I had a problem where the C string had a tiny bit of Buzz in it. I think it may have been from the string actually vibrating back and forth on the bridge. So I can only assume that I don't have a sharp enough string angle behind the bridge. Does that sound right? What angle do your strings have there?
 
Does that mean the backside of the bridge shoud have a 15to 20 degree angle, or when doing through the body holes they should be angled? Since pegs are straight up and down, I don't think it's the holes. So even compensated saddles shoul have a backside taper? How much contact should strings have with the saddle and the nut?
 
TheCraftedCow said:
Does that mean the backside of the bridge shoud have a 15to 20 degree angle, or when doing through the body holes they should be angled? Since pegs are straight up and down, I don't think it's the holes. So even compensated saddles shoul have a backside taper? How much contact should strings have with the saddle and the nut?
Click to expand...

Okay, I'll bite because I'm in the mood. . .

In order of your questions:
No. What body holes?
Why would we assume that there's pegs . . .do you mean bridge pins?
Not sure what compensated saddles have to do with this topic, but Taper wouldn't dictate most of the angle, but could be a variable.
Not sure what the question has to do with back angle - the nut is 17" away fom the saddle. . .

-Aaron
 
Last edited:
Lets draw a picture shall we....

Draw a line representing the string from the saddle to the nut. Doesn't have to be that long but it's basically a horizontal line. Now draw your bridge and saddle at one end. Be pretty accurate here. Now the break angle is the angle the strings take as they cross over the saddle and go down to whatever fixing point you have. Be that pins, through the bridge, or knotted on a tie bridge. It will be a straight line with a contact point on each end. One the saddle and the other it's anchor.

Hope that helps.
 
BTW, to the OP, are you sure the buzz is from the saddle? Of course, I've heard of some instruments with a flat saddle intentional to buzzing. BUT, that may be only an internet myth. Outside of being absolutely sure that the buzz is not elsewhere - maybe try a string change. If you really think about it, it takes a lot to move the string between the saddle and the tie block.

Not sure what the break angle is exactly, but here's a shot:
IMG_0341.jpg
 
This whole string break angle thing has always stumped me because everyone seems to explain it differently. I just drew it out a bunch of times and sorted it out.

I can't help but think of it in terms of geometry. An angle must have two rays, I guess we are talking about the string behind the saddle as one ray (the bit between the saddle and attachment point).
1. If we take the string between the saddle and nut as the other ray we get an angle of ~160ish degrees.
2. If we take the saddle itself as the other ray we get ~70ish degrees.
3. If we take the string between the saddle and nut and do an imaginary projection back over the saddle and then take it as the other ray, then we get ~20ish degrees. Seems like the most difficult way to think about the system........................

I suppose I'm thinking too much again................
 
Kekani said:
BTW, to the OP, are you sure the buzz is from the saddle? Of course, I've heard of some instruments with a flat saddle intentional to buzzing. BUT, that may be only an internet myth. Outside of being absolutely sure that the buzz is not elsewhere - maybe try a string change. If you really think about it, it takes a lot to move the string between the saddle and the tie block.

Not sure what the break angle is exactly, but here's a shot:
View attachment 32316
Click to expand...

Forget about geometry and math for a second. I agree with Aaron in that I'm doubtful the buzz is from the saddle. I know that it sounds like it's coming from the bridge but it's more likely vibrating against one of the frets due to uneven frets, insufficient relief, improper tension of the string, etc. The C strings is always the most problematic due to it's thicker diameter and wider vibrating arc.
 
From the photo it looks like you might have a flat spot on the saddle. That can give you a buzz or sitar like sound
Make sure the saddle is peaked with only one point of contact with the string. (not so sharp that it cuts the string, of course)
 
I have a uke where part of the bridge in between the string hole and the saddle barely touches the string. Is that a mistake?
 
ksquine said:
From the photo it looks like you might have a flat spot on the saddle. That can give you a buzz or sitar like sound
Make sure the saddle is peaked with only one point of contact with the string. (not so sharp that it cuts the string, of course)
Click to expand...

That would be one of mine, not the OP's. And the flat spot you're referring to is the back angle on the saddle, which is actually less than a "normal" saddle because there's 7.5 degrees of back angle in the saddle slot, but that's another thread.

Sitar- that's the myth I heard about.

- Aaron
 
Moore Bettah Ukuleles said:
Forget about geometry and math for a second. I agree with Aaron in that I'm doubtful the buzz is from the saddle. I know that it sounds like it's coming from the bridge but it's more likely vibrating against one of the frets due to uneven frets, insufficient relief, improper tension of the string, etc. The C strings is always the most problematic due to it's thicker diameter and wider vibrating arc.
Click to expand...

Since most ukes do not have a truss rod, do you build some relief into the neck?
 
luvzmocha said:
Since most ukes do not have a truss rod, do you build some relief into the neck?
Click to expand...

Always. My necks (all sizes) are all reinforced with carbon fiber so I include a bit of relief. Ukes with necks that aren't as stiff will likely develop some relief on their own in time. Sometimes too much. sometimes not enough. Some may think that CF reinforcement is overkill on an uke but for six bucks it's cheap insurance.
 
Relief in neck, you bet. I use CF in the neck as well. Pretty easy to do as well. Put a shim under the area you are wanting the relief while you are shaping the playing surface of the board. For me it's between the 5 and 8th fret. It raises that area up just that little bit so more material is removed, thus giving more relief when glued down onto your neck.
 
Moore Bettah Ukuleles said:
Forget about geometry and math for a second. I agree with Aaron in that I'm doubtful the buzz is from the saddle. I know that it sounds like it's coming from the bridge but it's more likely vibrating against one of the frets due to uneven frets, insufficient relief, improper tension of the string, etc. The C strings is always the most problematic due to it's thicker diameter and wider vibrating arc.
Click to expand...

As the owner of one of the ukes the OP is referring to, I'll throw in my 2 cents. BTW, it's a beautiful uke, especially for a pretty new builder. Here are the facts as I know them, feel free to reach your own conclusions:

1. When plucked over where the soundhole would be if it were a standard uke (it has an upper bout soundhole, but I'm talking about where the location of the soundhole is on most ukes), it buzzes, whether played open or fretted on any fret. The buzz is not profound, but can be heard.
2. When plucked over the 12th fret, it does not buzz at all, again, whether played open or fretted at any fret (well, any fret, below 12).
3. The C string has play at the saddle, by which I mean I can I move it back and forth a bit in either direction with light finger pressure. I can't move any of the other strings at the saddle.

Thoughts?
 
Don't forget to check for sympathetic buzzing from hardware, making sure everything is tight on your tuners and pickup (if applicable). Also try flipping your saddle around and see if it still buzzes. From your description it could even be a loose brace, as unlikely as that may be.
 
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