Curved frets

[simso]

So, a while back(2-3yrs ago) I was asked whether I could do a curved fret installation, I turned the job down because it was beyond my grasp of knowledge, unknown quantity and tooling. However recently a good friend has made me revisit the topic.

Now with cnc I can do a compound radius and curved fret slots with a sealed solid edge. So my interest is peaked again, and Im possibly going to do one as a trial run.

Has anyone here done this. If so what are the pitfalls.

[Nick Payne]

What's the advantage? I can only see disadvantages. You'll have to curve the saddle also. And I can't see a repair shop wanting to handle a refret or recrown when one is needed. In fact, how would you crown the frets after levelling them?

[simso]

The theory is, that every fret is 90 degrees to the string and all string lengths are the same for each fret position, therefore you dont get unequal scale lengths.

On a conventional setup, strings one and six are the same scale length, 2 and 5 are different and same for 3 and 4, so basically your running three different scale lengths.

The theory is good, but as I said when I was approached to do this years ago, it was the umm yeh, umm wtf, umm mmmm.

Now that Im tempted through modern technology to revisit this idea, Im curious.......

[kiwigeo]

I cant see any practical reason to curve frets either...except for visual effect. Fan frets make more sense but curved frets just dont. Or am I missing something?

[simso]

I like fanned frets, perry does them as part of his guitar range.

Im not for or against, just like tru temperament frets, people want them and as a repairer my job is usually to do the job, not to question the thoughts of the customer. But sometimes requests even surprise me. Im revisiting this one, becuase it was one that I originally turned away

[kiwigeo]

The theory is, that every fret is 90 degrees to the string and all string lengths are the same for each fret position, therefore you dont get unequal scale lengths.
.

Maybe if the saddle was a metre wide the strings might significantly deviate from 90deg but on a guitar with normal dimensioned nut and saddle exactly how far off 90deg are the strings to the frets and exactly how much does it affect intonation? Sounds like someone has invented a solution for a problem that isnt there. Would be interested to hear from anyone with a differing view on the subject.

[Trevor Gore]

The difference between long and short strings on a conventional guitar with straight frets is a maximum of ~0.15mm with an associated interval error of ~0.4 cents. You may just be able to see the curve in the frets (provided you don't have any spherical aberrations in your vision), but I doubt you'll hear it! Equal temperament has thirds which are ~14 cents sharp of Just.

Now I'm going to do something more exciting....

Happy New Year everyone.

[jeffhigh]

And with the conventional fret layout everything is in equal proportion along the length of the string anyhow so it does not matter. the curved frets will not give any better tuning.

[simso]

As I said, Im not for or against, but challenges to ones current style of doing things are always good.

TT's who has done them, I know I havent, but am definetly keen.

[Allen]

No disrespect to you Steve, or wanting to get on top of a challenge....but that just seems to be someone who has bought into the notion that if the ultimate instrument has been built and set up to be so perfect that the most precise and scientific tests and observations can't find fault, then obviously it will make them the ultimate of muso's. Money will start falling from the sky....oh brother.

What do all those poor sods do on fretless instruments? How could they possibly manage to put that finger down in the precise spot? Let alone make beautiful music:roll:

[Ormsby Guitars]

challenges to ones current style of doing things are always good.

YES YES YES. Just because something was done before, doesnt mean it was correct. Challenge everything! Prove everything yourself. You have the perfect attitude. Too many people blindly do something for no other reason than someone else had done it before. Case in point, standard nut positions.

I have considered the curved fret idea, but more with respect to having a considerably longer scale length on the bass side. Eg: curved fanned frets, or rather, exponential multiple scale lengths? I then looked at this method you posted up, but with the centre of the radius being the imaginary intersection of the strings (obviously past the headstock). Once you start getting into curves that are only measurable in the low single digit thousands of an inch, you have to wonder how accurate your crowning methods are!

I then calculated how much time Id spent working that out, and realised I could have built a whole guitar

[Ormsby Guitars]

Also, I tried three TT retrofits (two on Flaxwood guitars) and didnt like them. Action was good, intonation was good for the most part, but it was out in a bunch of spots. I honestly felt (and so did one of the owners of the TT guitar) that a well compensated longer scale (25.5 rather than 24.618) instrument just sounded nicer. We went as far as eqing the guitars to sound ultra similar in tone, and then blind tested the recordings with a few people... rather than be biased with having an instrument in front of us.

You cant level and crown them, you must send them back to the factory. Being cast frets, they needed a bit of maintenance to keep them nice, and they did seem to wear faster. $1000 for a retrofit if I recall... plus 2 x postage.

[kiwigeo]

Maybe its just me but 90% of the guitarists I see with TT fretted guitars are shredders.........call me biased and old fashioned but who the hells going to notice intonation is slightly out halfway through a no holds barred Defcon 1 melt your balls off shredding session??

Anyway its New Years Eve and there are other matters to attend to that are far more important than any shaped fret.

Have a great New Year everybody!!

[simso]

Who saids were not doing both, Im thinking - typing, cad drawing and drinking, and the wife saids I cant multi task, what does she know.

[kiwigeo]

Who saids were not doing both, Im thinking - typing, cad drawing and drinking, and the wife saids I cant multi task, what does she know.

No...men dont multi-task. Our brains are like an 86 series computer chip....what we call multi tasking is actually time slicing ie multiple tasks are going on but a small part of only one task is going on at any one time.

This is why I left my glue bath on all last night.

[simso]

Been playing with new cnc programs, just finished drawing this one up. This one here has a compund radius with fret depths cut in relation to the top surface profile

Change that to a curved shaped fret slot on a bound board, some inlaying etc, could be quite spectacular the end results.

Shame I dont actually make guitars.

Program estimates machining time on cnc as 6 minutes 14 seconds

[Ormsby Guitars]

Shame I dont actually make guitars.

Sounds like a good enough time to make a new years resolution

What software do you prefer? Im yet to purchase anything after getting a CNC back in September.

[simso]

Martin, it now takes 7 minutes and 40 seconds.

Profiled with the compund radius exactly readu to be inlayed

[simso]

Nah perry, leave that to you mate.

Not enough hours in the day as it is. Repairs repairs repairs, thats enough for us..

[kiwigeo]

Martin, it now takes 7 minutes and 40 seconds.

Profiled with the compund radius exactly readu to be inlayed

Looks dandy. Unfortunately my guitars have yet to reach a quality of build where Id be comfortable putting my name on the instrument.

[simso]

I was bored, too many stubbies accumulating next to computer