|
|
Joined:
May 2010
Posts: 95
Location: Vancouver Island, BC | I have to make a custom saddle for my 1973 Artist Balladeer (the old 1/8" thick type).
Near as I can tell from old brochures etc Ovation always used a 10" fretboard radius.
Should this be matched by a 10" radius at the saddle? |
|
| |
|
Joined:
May 2010
Posts: 95
Location: Vancouver Island, BC | The answer is YES (from a local luthier). So I made a radius gauge and shaped the saddle accordingly. Great improvement in playability, and proper string height across the fingerboard (the old saddle was slightly "flat", from a guitar with a larger radius).
In the end probably a stupid question, but with a good end result. |
|
| |
|
Joined:
September 2006
Posts: 10777
Location: Keepin' It Weird in Portland, OR | I didn't answer cuz I didn't want to give you bad advice...
But I have had steel string Ovations with flat saddles.
I have always replaced them with arched saddles.
But I did not know if the radii matched exactly, or if the radius of the saddle was different for the fingerboard.
I just went by eyeball...
Glad that you got it to work correctly.
|
|
| |
|
Joined:
April 2003
Posts: 608
Location: Caribou, ME | I've heard it argued that if a fingerboard had a 10" radius, the radius of the strings would have to change by virtue of the fact they are raised off the fingerboard. Assuming the goal is to have all six strings equally "off" the fingerboard by let's say 6/64" at the 12th fret, then the radius of the strings would be about 10-6/64". In order to achieve that, the saddle would have to have an even greater radius.
I don't know how much of that is true, I'm not an engineer. I know I just sat here with an old elementary school grade compass and experimented. I made an arc using a 2" radius, then another with a 2-1/2" radius. As one might predict, the distance between the two arcs was 1/2". However, if I shifted the pivot point 1/2" and made another arc (thus modeling a situation where your strings at the 12th fret matched the fingerboard radius), the distance was greater in the center of the arc and less at the edges. So I guess the radius should be flatter than the board.
Now the example I used was extreme as it compares to a 10" fingerboard radius and that little bit of difference probably wouldn't amount to a hill of beans but it's just a caveat to not strictly adhere to the fingerboard radius.
To complicate matters, the goal isn't typically to have an equal height on the strings anyway! I try to have E1 a couple 64ths lower than E6.
Not an engineer. OMA has the right idea. My experience is that most saddles are flatter than they should be. If I were in that situation I would guesstimate how much I needed (or dared) take off the saddle at each end to achieve the desired height by measuring at the 12th fret, figuring how much change I had to make there, and then doubling it for the amount needed to come off the saddle. Then I'd shape the rest of the saddle until it "looked right". How's that for anti-engineer talk?
I've had way too much coffee. |
|
| |
|
Joined:
May 2010
Posts: 95
Location: Vancouver Island, BC | This is good!!
My thinking was along those lines, but not as scientific. A slightly larger radius at the saddle, as the strings are slightly farther away from the center of the radius. Say 10-6/64" at the 12th fret, and 10-12/64 (10-3/16" at the saddle.
Also, like you say, the E-1 should be slightly closer to the finger board than E-6, so the center of the radius should be slightly off-set toward the E-6 side. Probably too scientific, but if you were designing guitars, this would be important.
I think this is where "it looks about right" comes into play, and hacking out a radius gauge from Arborite wasn't too scientific, but it sure improved the guitar.
Problem is: all my guitars (9 to be exact) are Os, so if I bought the set of 9 radius gauges from Stewmac, 8 of them would be useless.
Necessity is the mother of invention.
Thank you both for great input |
|
| |
|
Joined:
April 2003
Posts: 608
Location: Caribou, ME | Geometry about drove me nuts a few years back when I was handed a mid 50s Gibson LG-1 that had largely fallen apart in the attic of someone's house and to make matters worse, had been moved several times. The back had popped off and some of the ladder bracing had come unglued and fell out of the body entirely... and lost.
I made new top braces but in order to get the radius right (Gibson flat tops are NOT flat) I had to enlist our engineer at work. I learned all about sagitta and promptly forgot it. Long story short, a Gibson with a 21 or 22 foot top radius (whichever it was) and a top brace of about 14", needs to be 1/8" taller in the middle than on the ends. I drove 3 push pins into the wall and used that as a template when shaping the brace on the belt sander.
Science is great but I bet I could have eyeballed it and called it "good enough".
Edited by ksdaddy 2013-05-16 7:36 AM
|
|
| |
|
Joined:
October 2005
Posts: 4025
Location: Utah | I installed a Tusq 12" radius saddle which seems perfect in my Patriot (1976 round hole deep bowl). It is the fully compensated 1/8" thin one. StewMac lists it as model 3558 (may be their own internal number not a Tusq model number).
If the radius is too large the strings will not be at similar heights above the frets. The middle strings will be close to the frets, the top and bottom strings will be far from the frets. If the saddle radius exactly matches the fretboard the middle strings will be too far from the frets. Note that the strings are closer together at the nut than at the saddle, so the strings are "flatter" at the nut than they would be at the saddle given the same radius. The nut may be a much flatter curve (larger radius) than the fretboard depending on how it is cut, too.
According to the internet, the saddle radius should be slightly bigger than the fretboard radius. This can be seen when setting up an electric guitar with individually adjustable saddles for each string. The Tusq 12" radius works fine on my old Ovation, whether or not it matches the theoretical calculations to the 3rd decimal place. |
|
| |
Fingerboard radius vs saddle
