Cutting Multiscale Fretslots through a radius

Discussion in 'Luthiery, Modifications & Customizations' started by Grand Rabbit, May 31, 2017.

  1. Grand Rabbit

    Grand Rabbit SS.org Regular

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    It's a mystery to me how one would cut diagonal fret slots through a fretboard with a radius.

    since the perpendicular axis of the fret slot would be twisting slightly over the radius of the fretboard, would one be limited to a cnc machine to get the right slot cuts, or could you just go straight through with a standard cut at an angle?

    I know, at the very least, the fret will have a slight twist to it as it bends over the radius at a diagonal, but does the slot itself have to be cut with this twist in it for the frets to sit properly?
     
  2. MikeNeal

    MikeNeal SS.org Regular

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    Best to slot the board before putting the radius on it
     
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  3. KR250

    KR250 Build addict

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    What I've done is to cut shallow slots before radiusing, then once that is done I go back over with a fret saw using a depth stop to deepen the cut to the same depth all the way through. Didn't have any issues as a result of the radius and the angled cuts.
     
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  4. Grand Rabbit

    Grand Rabbit SS.org Regular

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    No issues at all with diagonal slots? I've been debating that with a friend of mine as to whether or not the cuts would need to twist slightly along with the frets... but hey if your builds have been successful with straight cuts then I suppose it isn't such a big deal!

    Exciting news, I was not looking forward to relying on outsourcing a cnc service for multiscale fretboards
     
  5. KR250

    KR250 Build addict

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    Check out "build 2" in my signature, it's a 27" - 25.5" multi scale. Didn't have any issues cutting slots or pressing in frets. The radius is 16" so it's fairly flat. I'm actually about to re-do it with stainless frets so I'll try and take some close up pictures of the process.
     
  6. ElysianGuitars

    ElysianGuitars SS.org Regular

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    Most fretwire is pliable enough to conform to the fretboard surface, as the amount of twist isn't that severe. Just need to slot your fret so there's enough depth at the extreme ends of the slot after radiusing. Stainless has the hardest time twisting, but proper clamping and gluing of the fret alleviates this, as well as not over-radiusing the wire before you hammer it in.
     
  7. Lemonbaby

    Lemonbaby SS.org Regular

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    You seem to over-think something. The fret slots are still straight in a multiscale fretboard. The radius of all frets won't be the same but that doesn't create any problems.
     
  8. Winspear

    Winspear Tom Winspear

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    Yeah, I mean, I don't have experience with this but I don't understand the difference. You're cutting a straight line just at an angle. What does it matter if the surface you are cutting into is flat or not? Get your slotting jig lined up either side of the board and cut away until the desired depth is met :) There will be some twist to the fret like Elysian says, but it would be no different if the board were cut on CNC with frets slotted and then radius. The slots are always just a simple straight cut.
     
  9. LiveOVErdrive

    LiveOVErdrive CNC hack

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    It isn't exactly the same. If you think about the flat bottom of the main fret mass, it will twist in an angled slot slightly to conform to the radius. Think about wrapping a ribbon around a pole or whatever.

    But yeah I'd go with what other people are saying and assume that the amount of twisting will be fine with straight slots and the medal will bend into shape just fine.
     
  10. Grand Rabbit

    Grand Rabbit SS.org Regular

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    I think, ideally, the fret slot actually would twist ever so slightly underneath the fret. That would help with twisting the harder fret materials like stainless, and ensure an absolutely perfect fit. However, I don't think it's necessary. I'm gonna go ahead and jump into a multi scale build soon, and I'll cut the fret slots at diagonals just as i would have cut horizontal slots. I'll post some updates once I get there
     
  11. laxu

    laxu SS.org Regular

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    The only difference that would make is that there would be less empty space under the fret. Most multiscale guitars have pretty large radius anyway so in reality it would not make any noticeable difference. The fret is bent and hammered or pressed in so it conforms to the contours of the fretboard surface.
     
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  12. IGC

    IGC SS.org Regular

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    -It is not quite clear to me if your questioning weather the fret wire / slot will need to twist, from low to high string for a multiscale?

    -are you talking compound radii fretboard?

    -it sounds like your mixing up the fretboard bow or neck relief as the fretboard radius?

    -Anyhew, I just fretted and strung up my first 9 string 28 x 30 Multi-scale 9 string build, the intonation is surprisingly excellent.
    I used the Rick Tune fret spacing calculator.
    And sawed the fret slots before sanding the 19.25 fretboard radius.

    It being my first build, I'm stoked!
     
  13. dpm

    dpm Oni Guitars Contributor

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    Like Adam said, fretwire is pliable so it can conform to the tiny twist necessary.
     
  14. IGC

    IGC SS.org Regular

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    Ooooh, I think i see what your getting at! Sorry for any misinterpretation, or condescension ism (none intended :D)

    In theory,
    -IF your fretboard was perfectly FlaT..., and you chose a Multi-scale fret wire layout. The zero fret wire (or bridge line), IF, you NeveR clipped that wire flush with the edge of your fretboard, would extend at the chosen "multiscale" angle, to a common "apex point" meeting with the highest fret wire of the multiscale (24 th fret or what ever) If not clipped flush with the edge of your fretboard and extending to infinity. No curling of the fret wire because the fretboard is perfectly flat! Haha!

    - However, if you choose to cap your fretboard with a typical fretboard radius. After installation, the fret wire must seat itself flat onto (parallel with) the chosen fretboard radius. You don't want to feeler gauge a .005 in. gap under the installed fret wire! Can I get a wut wut :D

    - IF we don't clip the zero fret and 24th fret wire flush to the edge of the fretboard. Allowing them to extend to the chosen multi scale fret layout "apex". Considering we now have the chosen fretboard radius and the fret wire MusT lay flush/parallel/ curl with the fretboard radius. WILL the fret wire actually generate a geometrical twist along its journey to the theoretical multiscale "apex" ???

    -It is hard to say exactly, I think so... But, the actual fretboard section of the multiscale layout and any respective fretwire "twisting" generated within ITS realm of the TOTAL multiscale layout, apex to lowest string. Surely must be such a minute amount that it is completely insignificant!
     
  15. Grand Rabbit

    Grand Rabbit SS.org Regular

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    :yesway: indeed, I had forgotten to factor in the malleability of fretwire

    Thanks for the replies everyone, this has clarified my minor vexation.
     
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  16. LiveOVErdrive

    LiveOVErdrive CNC hack

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    Also this has been an incredibly difficult topic to discuss on a forum.

    3d geometry, discussed only in text.
     
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  17. IGC

    IGC SS.org Regular

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    Oh yeah, just gotta say, I used jumbo stainless steel fret wire and have no problems with it seating properly on my multi scale neck. :D
     
  18. Grand Rabbit

    Grand Rabbit SS.org Regular

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    What techniques did you use to seat the frets into the slots? Stainless Steel's pretty damn tough so I'm wondering if simply hammering them would be enough
     
  19. IGC

    IGC SS.org Regular

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    Not hammering... I used an aluminum fret caul with the precise fretboard radius. and a "C" clamp. I will post a picture later- kind of hard to explain. But the caul was on one side of the C clamp and a block of wood (to protect the neck wood) on the screw side of the C clamp. :D
    This distinguished papyrus guy on here that builds uses a hard wood caul with the fretboard radius filed in.
    Glad you posted back because i'v been OCDing this and have further clarified the twisting fret wire concept...contrary to what i stated earlier, actually it does not twist... it gets a little technical but I'm pretty sure I have it...
     
  20. dpm

    dpm Oni Guitars Contributor

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    The tang bends slightly relative to the crown.

    In some ways stainless is better to work with than nickel silver. NS is softer but it has a little more spring to it. Stainless is harder but when forced into shape it tends to stay put rather than spring back. One of the reasons I don't bother with EVO wire now is it's the worst of both worlds in that regard. It's hard and springy.
     

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