Does fret radius have to match fretboard radius?

[eddie_bowers]

I'm finally getting around to leveling the frets on my kit guitar.
12 inch has always felt a bit flat for me. could I use a 10 inch block to fudge it a bit and get a more comfortable radius?

 

[Mistrals60]

All of the radii should be identical; fretboard, frets, bridge. You would have one messed up guitar if you tried that.

Of course, this is just my opinion.

 

[eddie_bowers]

Why?
The inner strings might be more sensitive to string/finger pressure, but I don't press hard enough to bottom them out anyway.
I need a real reason why this would be a problem (messed up doesn't help me).

 

[jcsk8]

I think you could have problems to crown the frets properly after the job. As the frets would be flater on the fretboard edges than the center, you may run out of enough fret height to round them nice as they should be. But it will depends on the type of frets involved.
A corret job would be round the fretboard and then a refret.

 

[pshupe]

If you need an answer, do it and let us know if you have to start over! ;-)
Then we'll all know at your expense. Works for me!

Cheers Peter

 

[bruce bennett]

whoops I just re-read your question.. your title is misleading..

if you want a 10" radius then sand your board to a 10" radius.. dont' try to sand a 12" radius fret to a 10. you'll have a very uneven fret profile that will be difficult to crown properly...

now that said...will it work? can it be done?..

yes it can.. but that is an advanced technique and if you've never done it. you be in for some surprises that may not be so fun.

 

[fatdaddypreacher]

i may be wrong, bruce, but i don't think he was talking about what radius they should be prebent to before installing. I'm taking it that he has them installed and wants to file them to a 10" radius on a 12" radius fretboard.

i'm with jcsk8. , and will add that the problem jc is talking about when it comes to crowning will only get worse the closer you get to the bridge end.

as far as bruces's answer, that's good info. I never would have considered a difference in stainless and nickle fretwire. apparently ss is rather stiff.

 

[bruce bennett]

i may be wrong, bruce, but i don't think he was talking about what radius they should be prebent to before installing. I'm taking it that he has them installed and wants to file them to a 10" radius on a 12" radius fretboard.

i'm with jcsk8. , and will add that the problem jc is talking about when it comes to crowning will only get worse the closer you get to the bridge end.

as far as bruces's answer, that's good info. I never would have considered a difference in stainless and nickle fretwire. apparently ss is rather stiff.

yeah I figured that out after I posted.. but I went back and fixed it.. Thanks!

 

[Roman]

I'm taking it that he has them installed and wants to file them to a 10" radius on a 12" radius fretboard.

Recipe for disaster.

 

[fatdaddypreacher]

i know i don't want to tackle that. i feel like i've accomplished something when i just get one to play halfway decent without trying something like that.

 

[Tenafly Vipers]

I have seen some guys who build necks with the opposite treatment. The frets are at a 12 and the board is a 9.5 or something. I wouldn't do it. I had one but ended up having to even everything up.

 

[eddie_bowers]

ahh, so crowning is going to be the problem.
That makes sense.
I think I'm adequately scared to try it now
Oh well it was with asking.

Thanks guys!

 

[fatdaddypreacher]

whew! I was afraid for you for a minute there.

 

[Roman]

If you know how to do fretwork, pull 'em, re-radius the board and refret. No problem.

 

[Jim_E]

I could be wrong, but…

I just “did the math” and the difference in height between the two radii (12 inch and 10 inch) measured at the crown of the widest fret, is .0104 inches or .264mm – and the difference decreases as you move towards the first fret, so that’s worst case scenario.

I think based on the numbers you could change a 12 inch to 10 inch radius within the fret thickness with little effort.

Talking in generalities, .0104 is about 20% of the “average” fret height.

It shouldn’t be an issue to crown an “average” fret, taller ones would be pretty much no issue and you may have an issue crowning a low fret, say one that measures .03 inches.

 

[Roman]

Doing the math and the real world are two different things entirely. Sure, someone with skill could pull it off, but then again they'd have the common sense to plane the board to the proper radius and refret it.

What the hell do I know, I've only been doing this stuff day in and day out for 30 some years.

 

[Jim_E]

Doing the math and the real world are two different things entirely. Sure, someone with skill could pull it off, but then again they'd have the common sense to plane the board to the proper radius and refret it.

What the hell do I know, I've only been doing this stuff day in and day out for 30 some years.

Pretty much what I expected to hear... sorry I'll just leave out the math and deal with another reality, the real one...

 

[Freddy G]

And don't use a radius block to level frets! The radius block is to radius the fretboard....get that perfect, then seat the frets perfectly and you'll have very little "fix it in the mix" work...leveling the frets (sorry I couldn't resist the audio analogy )

And to address the comment about all radii should be identical or you'll have a messed up guitar. Not so! I always make the radii of both the nut and the bridge slightly flatter than the fret radius.
Think about why....
OK...at the bridge, the height or action of the high E gets set right? Then every other string gets set slightly progressively higher so that the low E ends up maybe 2/64" (yeah, yeah I know....1/32" ) higher than the high E. Same thing at the nut, although to a lesser degree. This results in a flatter radius than the frets. If you were to maintain the exact same radius at the bridge as the frets while giving the low E more height, then the middle strings (D & G) would be needlessly high.

 

[Pickup]

And don't use a radius block to level frets! The radius block is to radius the fretboard....get that perfect, then seat the frets perfectly and you'll have very little "fix it in the mix" work...leveling the frets (sorry I couldn't resist the audio analogy )

And to address the comment about all radii should be identical or you'll have a messed up guitar. Not so! I always make the radii of both the nut and the bridge slightly flatter than the fret radius.
Think about why....
OK...at the bridge, the height or action of the high E gets set right? Then every other string gets set slightly progressively higher so that the low E ends up maybe 2/64" (yeah, yeah I know....1/32" ) higher than the high E. Same thing at the nut, although to a lesser degree. This results in a flatter radius than the frets. If you were to maintain the exact same radius at the bridge as the frets while giving the low E more height, then the middle strings (D & G) would be needlessly high.

Thank you so much Freddy G! Always straight, plain, and practical sense without any snake oil.
Your view on this is exactly what I have always suspected to be the truth of the matter.

Despite the most exacting attention and adjustment to match the bridge/saddles/slots radius precisely to the fretboard radii, I have never been happy with the results. I always felt the centre strings to be too high - especially of course, high up the fretboard. e.g. I have never been comfortable with the height of the centre strings on my SG (with a maestro.... so note the low string angle over the bridge). However, my LP is not so bad since with a very low tailpiece, the bridge has flattened just a little, and consequently has a flatter radius.

Now I am happier because I don't feel alone in my concerns about the plethora of advice commonly available, which goes no further than stating that we all setup our bridges perfectly according to a radius guage alone.
I am at a loss to understand how certain well-known luthiers who demonstrate and recommend these items can actually have happy customers using this method.

Well, my question here only deserves an answer of "Well ... it all depends, and will vary according to other factors". But I'll try anyway .....
What is a good starting point radius at the bridge, for a 12 inch radius fretboard? (If it's relevant, say with 10 gauge strings and an average 3/64 1st and 5/64 6th action) Would you say 14 inch... and then see how it goes from there?
Thank you so much once again!

 

[Roman]

I don't know if there is much intentional "snake oil" being disseminated. Seems more like a dumbed down approach based on easily digested standards, and the desire to sell tools.

I have some of the stainless radius gauges, but the only practical use for me is to check the radius of the fingerbaord...........that's it.

Most boards I do are a compound radius.

Now onto setups......... I like freddy's approach, and follow that logic to some degree, but have my own twists based on player input.

My nut height and radius pretty much follows the neck radius but with the bass side being higher than the treble.

Yet on the bridge, it is the opposite. Yup, the treble side is higher than the bass side when a player wants overall low action.

Why? The treble strings are the ones where the majority of the string bending occurs.

I'll set it up so the action is pretty low to where there is no buzz when fretting without the bends. Seeing how many players do very little bending of the wound strings, you can get away with a lower action.

On the high E and B, the more you bend the string, the closer it gets to the top of the hill of the radius. It will crap out because the string takes a diagonal angle the more you bend it. You have lost the right angle to the fret relationship as soon as you bend. The closer you get to the top of the hill the more the vibrating portion of the string comes into contact with the higher frets, causing it to crap out.

The more the player bends a note, the higher you have to bring the string to get the clearance.

The B string needs a bit less clearance, and the G needs even less, because the G is already at the top of the hill,and the more you bend it you are going down hill.

So in short, adjusting the strings to the radius is useless....unless you have a really flat radius.

I hope some of this made sense.