Can you modify a 12” radius bridge to 16” radius

Chef T

Electromatic
Dec 12, 2020
91
New York
Hi, I have a graphtech resomax bridge on my gretsch electromatic 5222 and love it. I want to put the same bridge on my Dangelico excel mini DC but the fretboard radius is 16” and graphtech only makes the resomax bridge with 12” radius. I am thinking I can use a 16” radius block and just sand the saddles, but am not sure if that will work and don’t want to waste $100. If anyone knows if this is possible please let me know.
Happy Thanksgiving
Todd
 

Ricochet

Senior Gretsch-Talker
Gold Supporting Member
Nov 13, 2009
22,731
Monkey Island
I’d say so. From the FAQ:

What if the strings start to dig into the saddle?

If you’re experiencing any kind of binding, you can easily fold a piece of 200 Grit sand paper and sand the notch off. Again, being a consistent material you can file/sand the saddle and you will still be working with the same quality material.



Can I modify String Saver Originals for my guitar?


Due to the consistency of our String Saver Originals, it is extremely easy to work with. You can easily modify it with fine grit sandpaper or other commonly used shaping tools. If we make a saddle that is close to what you need and you want to make the saddles slightly smaller, just sand each side slightly with some fine grit sandpaper.
 

Chef T

Electromatic
Dec 12, 2020
91
New York
Thanks, I guess I’m over thinking it. I taught myself how to level/crown frets,replace a nut and file nut slots to adjust string height on cheap guitars. And I know if I mess up It’s just a bridge and doesn’t permanently damage the guitar, but I am hoping someone on the forum has some experience with this and can tell me the best way to go about it. I have radius gauges and fret files and various grit micro mesh sandpaper. I know most of the filling will be the D and G string, I just don’t feel like wasting money right now by learning the hard way.
If nobody chimes in, I guess I will take one for the team and go for it!!
 

Chef T

Electromatic
Dec 12, 2020
91
New York
I like that idea! The more I think about it, just filing the tops of the saddles wouldn’t change the string radius at the bridge. I would still have to file the slots no matter what.
Thanks!!
 
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swivel

Country Gent
Silver Member
May 13, 2018
2,302
PNW
... and another thought: Compound radius necks cant be matched to a given bridge radius.......... and they work fine...
 

Chef T

Electromatic
Dec 12, 2020
91
New York
I don’t know how that works with a compound radius neck, but I believe the radius of the bridge should be very close to the fretboard radius in order to be able to have the string action even for all strings
 

Randy99CL

Country Gent
Gold Supporting Member
Feb 17, 2020
2,269
Albuquerque

Ricochet

Senior Gretsch-Talker
Gold Supporting Member
Nov 13, 2009
22,731
Monkey Island
A compound radius is a section of a cone, rather than a section of a cylinder like a fixed radius fretboard. There’s a formula on the Stew Mac site for working out bridge radius to match a compound fingerboard, it works out at about 3 inches more than the end of the fingerboard radius.

…depending on compound.
 

Chef T

Electromatic
Dec 12, 2020
91
New York
Thanks, I do have a set of radius gauges and I have done the string spacing and notched the bridge saddles once (Well twice, the first time the spacing didn’t come out perfect). It was on a wraparound bridge I bought from Stew Mac. They actually sent me the second bridge for free when I told them I messed up the first one! Then when I decided to buy the resomax bridge I spoke with Stew Mac and asked if I could file the saddles on a 12” radius bridge for a 16” diameter fretboard. They told me they don’t recommend using a bridge with more than 2” radius difference. That’s why I am hesitant with filing the saddles
 

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Ricochet

Senior Gretsch-Talker
Gold Supporting Member
Nov 13, 2009
22,731
Monkey Island
They told me they don’t recommend using a bridge with more than 2” radius difference. That’s why I am hesitant with filing the saddles

Of course, but in the context of filing the saddles down what 1.5mm that doesn’t make any sense.
 

swivel

Country Gent
Silver Member
May 13, 2018
2,302
PNW
Hi, I have a graphtech resomax bridge on my gretsch electromatic 5222 and love it. I want to put the same bridge on my Dangelico excel mini DC but the fretboard radius is 16” and graphtech only makes the resomax bridge with 12” radius. I am thinking I can use a 16” radius block and just sand the saddles, but am not sure if that will work and don’t want to waste $100. If anyone knows if this is possible please let me know.
Happy Thanksgiving
Todd
Sorry for the thread drift from my "compound radius" comment!

You mean the ones that look like a wood bridge? Or the ones with individual segments? I would think you could radius it from the look of it. Sanding with a radius block across the thin section bothers me a bit though. But I suppose doable with fine paper. It appears the difference in height between 12" and 16" radius, at the highest, is about .008-.009". (just measuring the two metal radius gauges laid on top of each other with digital calipers.) Not even 2 printing paper thicknesses....
I suppose I could calculate it... So let's see.... I guess that means your D and G string are maybe .008 higher off the frets than your high E and low E with the 12" radius bridge.

BridgeRad.jpg
 
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Chef T

Electromatic
Dec 12, 2020
91
New York
Seems to me that with a compound radius the nut has to match that end and the bridge the other, no problem.
You mean the ones that look like a wood bridge? Or the ones with individual segments? I would think you could radius it from the look of it. Sanding with a radius block across the thin section bothers me a bit though. But I suppose doable with fine paper. It appears the difference in height between 12" and 16" radius, at the highest, is about .008-.009". (just measuring the two radius gauges laid on top of each other with digital calipers.) Not even 2 printing paper thicknesses....
This is the bridge that I have/and want to put on my D’angelico. Thanks for the info!
 

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Chef T

Electromatic
Dec 12, 2020
91
New York
Sorry for the thread drift from my "compound radius" comment!

You mean the ones that look like a wood bridge? Or the ones with individual segments? I would think you could radius it from the look of it. Sanding with a radius block across the thin section bothers me a bit though. But I suppose doable with fine paper. It appears the difference in height between 12" and 16" radius, at the highest, is about .008-.009". (just measuring the two metal radius gauges laid on top of each other with digital calipers.) Not even 2 printing paper thicknesses....
I suppose I could calculate it... So let's see.... I guess that means your D and G string are maybe .008 higher off the frets than your high E and low E with the 12" radius bridge.

View attachment 195498
Thanks, that’s a great visual. I am guessing I will probably have to file down the tops of the saddles for the A,D,G & B strings after filing the saddle string slots.
 


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