fret leveling on a compound radius neck...

Discussion in 'Luthier's Guitar & Bass Technical Discussion' started by RockStarNick, Feb 17, 2008.


  1. RockStarNick

    RockStarNick Supporting Member

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    ... anyone ever do it themselves?

    Since it's conical shaped, a straightedge from the first to last fret still should lay flat on all frets, right?

    My Q is: how the heck do you level the frets, if you can't use a a radius block?
     
  2. David Collins

    David Collins Member

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    I never use a radius block for leveling frets anyway.

    In theory a true and even compound radius would have a tidge of relief on the edges if it were straight in the center. The geometry can be a bit odd to picture in your mind, but even a standard radius would suffer from the opposite in reference to what the strings see. It's very slight, but something to consider. To get a true flat plane for every string, in theory a slight compound radius of perhaps a 12 to around a 14 at the end would be ideal, though at this point we're really just talking numbers and theory. In practice, most skilled luthiers will dress something similar to this end goal whether they fully realize the geometry of what they're doing or not.

    There are enough tricks to fill a book to increasing your accuracy and dialing in relief in specific areas, but that's getting in to advanced fret work that can take years to learn. In short though, the key is to level with a flat plane, whether it be a file, plane sole, level bar, or similar tool. As moving lengthwise and across the radius with your leveling tools, each plane has to be leveled straight under the line of each string, with of course a smooth transition from one to the other.

    I've not bothered to figure the actual geometry and name of the end shape, but by the time the average compound radius board is trued up for practical use it would represent a section of a more flared rather than perfectly straight cone.
     
  3. RockStarNick

    RockStarNick Supporting Member

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    wow thanks david!

    OK so let me get this right:

    When I'm doing the actual leveling, when I have my flat sanding block (or whatever leveling device)

    am I moving it back and forth from the e string to E string, or from the low frets to the high frets?

    Id' assume the latter, since you have to get it flat in line with each string.
     
  4. David Collins

    David Collins Member

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    The latter is the most significant, as your main priority should be to level the surface under each string. At the same time, moving across the radius (from e to E) is important in insuring that the radius is smooth. It is somewhat common practice to move the leveling file in an arch or S-curve of sorts, keeping it in line with the strings as you file in the direction along their length while changing the the position across the radius throughout your stroke. This helps you keep from creating facets under each string, while maintaining a steady level along the string's length, if that makes sense.
     
  5. RockStarNick

    RockStarNick Supporting Member

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    That does make total sense.

    I'm going to give it a try. I did my first "fret level" on a throwaway BC rich neck, and got that thing suprisingly playable! My 2nd was on my friends Les Paul custom that was just pretty bad shape, and I just worked very slowly and carefully, and got the action really nice and low, with no buzz.

    I think If I take it really slow, I can manage to get the action really nice on my compound radius neck.

    thanks SO much for the info David.
     
  6. fullerplast

    fullerplast Senior Member

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    Also, keep the cone concept in mind and follow the imaginary string path as you level. Like David, I don't use a radius block, but I use a long steel block about an inch in width. Compound is not really much different than fixed when done that way.

    What I find helps greatly is to mark all the frets ahead of time with a blue or black marker. That way, you can see exactly what you are taking off across all the frets. When you are done, you should see that your file has at least touched all surfaces, the higher frets more than others, and you can see that you have leveled evenly across the width as well.
     
  7. GuitslingerTim

    GuitslingerTim Member

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    No need to imagine the string path. Take a long ruler and mark a line down the taped off neck between each corresponding nut and saddle slot with a Sharpie or a Magic Marker.
     
  8. Soapbarstrat

    Soapbarstrat Senior Member

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    Even less need to mark out the string path.
     
  9. RockStarNick

    RockStarNick Supporting Member

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    I ALWAYS use the sharpie trick when crowning and leveling. You just gotta!

    Besides a stew mac fret leveling bar, any other good ideas on things to use to get the job done?

    Anything I can get from home depot that would make a good leveling block?
     
  10. fullerplast

    fullerplast Senior Member

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    You can really use anything similar, so long as it's level. ;)

    A block of freshly planed hardwood would do the trick, but possibly not remain stable enough for your next fret level. The StewMac leveling bars are nice not only because of the flatness and width, but because the weight makes it easier to exert uniform force between strokes. You don't really need to push down as much as just move it along the neck.
     
  11. Bob V

    Bob V Member

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    I use the bottom of a Stanley #4 plane (without the blade), spray adhesive, and 320 or 400 grit silicon carbide paper. The sole of the cast iron plane body is perfectly flat and rather hefty.
     
  12. fullerplast

    fullerplast Senior Member

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    I like that double duty tool approach Bob!:AOK Bet it works real well. (Good tip on the blade too.....;))
     
  13. Bob V

    Bob V Member

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    Glad you like the idea, but I didn't come up with it. Shorter plane bodies actually work better. I had a problem with a long jointer plane because it was more than half the fingerboard length. As I hit the nut it extended past the middle frets, then as you go down to the other end you're still hanging over the middle frets and since they spend more time under the abrasive you wind up sanding some relief in. The shorter #4 seemed to be a good compromise between getting even attention to all the frets yet still getting the precision from a flat tool laying across several frets.

    Best bet is you get yourself a bargain on a plane at a garage sale by complaining that it has a chipped/rusted blade or is missing the lever or the cap iron. Right after you tell the guy with the '59 Les Paul from under the bed that the strings are rusty and ask him why he doesn't have the amp that comes with it.
     
  14. fullerplast

    fullerplast Senior Member

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    Yeah, I prefer a longer block but always take the nut off.

    Maybe I can get a package deal on the LP and the plane if I buy them both.....?:rotflmao
     
  15. Pannoowau

    Pannoowau Member

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  16. Keyser Soze

    Keyser Soze Member

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    A decent carpenter's level. I like the plastic ones with a metal edge.

    But check it with something that you know has a true straightedge. If it is not good then use sandpaper on a plane of glass to put a flat on it or take it to a machine shop and have them mill a proper flat into it.
     
  17. Soapbarstrat

    Soapbarstrat Senior Member

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    Leave Home Depot out of it. If you're going to take the time to go to a machine shop, just have them machine a piece of metal they already have in stock.

    If you've got a proper straight edge and find a nice flat piece of glass, make a fret leveler out of the glass.

    Like on this frets.com/charles fox guitars photo :

    http://www.frets.com/fretspages/features/cfox/CFoxViews/cfox127.jpg
     
  18. walterw

    walterw Gold Supporting Member

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    man, that looks like it would be a PITA to hold while leveling.

    i like the big straight bar from stewmac, because one, you can grip it easily, and two, being 2 feet long, you don't get the problem of sanding the middle down too much, since it's resting on the entire fretboard. (just make sure it's really flat like it's supposed to be.)
     
  19. Rob Sharer

    Rob Sharer Muso-Luthier

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    You definitely don't "gotta"; I've only done it once or twice, and I can't even remember why I did it then. Great if it works for you, but it's not necessary. You ought to be able to see what the stone/file is doing without the sharpie.

    Meanwhile, I've never understood the monster leveling block thing. I use a long straightedge to check, but a shorter level for maximum control during leveling. Cheers,

    Rob
     
  20. Dana Olsen

    Dana Olsen Gold Supporting Member

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    A sharpie gives you a way to see what's you've taken off the top of the frets, but it's not the only way to see that.

    Another way to see what you've taken off the top of the frets is to look at the pile of filings between each fret - a critical 'clue' that you just gotta keep your eyes on too (GRIN) as you're milling/ leveling the frets.

    I'm teasing, but only partly. The frets have to be seated into the fretboard - THAT job, when done well/ correctly, SHOULD leave those new frets pretty close to level in the first place. Some frets need to have more milled off the top, like 6105's which can feel "speed-bumpy' if left too tall, due to how narrow they are. 6100's though, ought to be pretty close when all the frets are seated in the fret board, before you ever start leveling them.

    Then, you need to check them with a level, and start milling. Keeping your eye on the material that comes off the tops of the frets, the dust that lays between the frets, is a critical clue to check yourself against "human errors' when filing, so you don't take more off one side than the other, etc.

    A sharpie line on the top of each fret will give you a clue as to 'where you're at' with the leveling, but there are other clues that a guy ignores at his own peril. I think it's safe to say that once the frets have been driven in, you need to check the level of the frets all over the fretboard, using your eyes and tools, before you start milling them.

    I'm really trying to say here that we all agree on the result - truly level frets - it's just how best to achieve that using repeatable methods. Fret leveling and shaping is truly one of the 'art' parts of of the refret process. My experience is the more refrets a person does in their daily repair lives, the better they are at it. I always take my guitars to someone who does it a lot, even though I know how to myself - 'cuz they're in better practice at it than I am.

    Thanks, Dana O.
     

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