What's the learning curve on fret leveling?

Thebluesman

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with practice...after initial neck preparation completed.. one can level [all] the frets within 10 mins.
crowning [removing the 'flats'] will take time
no room for errors.
 

Ronkirn

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Few really understand what Fret leveling does.. The one thing it does NOT do is result in level frets… Allow me to share…

When a fret is pressed into the wood.. it’s the wood and it’s density that stops it, Since the fingerboard is wood and presents varying densities to the respective fret being inserted, AND since there is no way to regulate the pressure to varying degrees to accommodate the wood’s inconsistent density.. each fret will assume a position slightly different than the others with precise uniformity being more a matter of blind luck than anything else.

While in the real world the differences are so subtle that most would never notice them, and the higher you like your action, the less noticeable any irregularities become.. your aware that it’s not level gets in your head and you begin to notice anomalies with more acuity… but…

The fingers are actually far more sensitive to such inconsistencies than many would believe.. therefore at an almost subconscious level.. you “feel” the inconsistencies in heights even though you don’t realize it.. This is why some guitars “feel“ so much better, even though they have precisely the same specs..

Now, why does a fret leveling not result in level frets… because of Science… the area that deals with thermodynamics.

As the frets are either initially inserted, or later, leveled, the process generates heat.. it may be subtle, bit it’s there non the less… what that does is cause the wood to expand and contract… and it has a cumulative effect, meaning whatever heat is generated is “multiplied” by the number of frets… Heat causes things to expand… and when they cool off rarely do the ever return to the exact null point where they started…

( note to Physicists, Mathematicians and those experts in other disciplines, I understand it’s far more complicated, but this isn’t a class at Cal Tech, it’s an open forum and some are still trying to find the definition for thermodynamics.. I’m trying to keep this at the Leveling 101 level.)

Thus you create heat by dragging a leveling tool over all the frets.. once you’re done.. the neck cools off, it cannot return to the exact point ya started. Thus it is no longer level.. but. . It’s not a problem… because of your subtle sensibilities…

Think of driving down a road full of pot holes, washouts, and other irregularities.. it gets old really fast…

Now think of driving down another road with a constant series of rolling hills…. Not so annoying..

That’s how your fingers navigate the fingerboard.. a unleveled fingerboard is like that road full of potholes.. ya never know how deep the next one will be… the neck just feels like it doesn’t cut it..

On a “leveled” fingerboard.. while it may acclimate after the process to a “rolling” up and downs… your fingers “see” it as far more pleasurable to play…

And that’s why .. you can never achieve ultimate performance, and playability from a fingerboard that has not been leveled..

Fret leveling is the single most notable "mod" one can have done to their guitar....


R
 

Boreas

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Few really understand what Fret leveling does.. The one thing it does NOT do is result in level frets… Allow me to share…

When a fret is pressed into the wood.. it’s the wood and it’s density that stops it, Since the fingerboard is wood and presents varying densities to the respective fret being inserted, AND since there is no way to regulate the pressure to varying degrees to accommodate the wood’s inconsistent density.. each fret will assume a position slightly different than the others with precise uniformity being more a matter of blind luck than anything else.

While in the real world the differences are so subtle that most would never notice them, and the higher you like your action, the less noticeable any irregularities become.. your aware that it’s not level gets in your head and you begin to notice anomalies with more acuity… but…

The fingers are actually far more sensitive to such inconsistencies than many would believe.. therefore at an almost subconscious level.. you “feel” the inconsistencies in heights even though you don’t realize it.. This is why some guitars “feel“ so much better, even though they have precisely the same specs..

Now, why does a fret leveling not result in level frets… because of Science… the area that deals with thermodynamics.

As the frets are either initially inserted, or later, leveled, the process generates heat.. it may be subtle, bit it’s there non the less… what that does is cause the wood to expand and contract… and it has a cumulative effect, meaning whatever heat is generated is “multiplied” by the number of frets… Heat causes things to expand… and when they cool off rarely do the ever return to the exact null point where they started…

( note to Physicists, Mathematicians and those experts in other disciplines, I understand it’s far more complicated, but this isn’t a class at Cal Tech, it’s an open forum and some are still trying to find the definition for thermodynamics.. I’m trying to keep this at the Leveling 101 level.)

Thus you create heat by dragging a leveling tool over all the frets.. once you’re done.. the neck cools off, it cannot return to the exact point ya started. Thus it is no longer level.. but. . It’s not a problem… because of your subtle sensibilities…

Think of driving down a road full of pot holes, washouts, and other irregularities.. it gets old really fast…

Now think of driving down another road with a constant series of rolling hills…. Not so annoying..

That’s how your fingers navigate the fingerboard.. a unleveled fingerboard is like that road full of potholes.. ya never know how deep the next one will be… the neck just feels like it doesn’t cut it..

On a “leveled” fingerboard.. while it may acclimate after the process to a “rolling” up and downs… your fingers “see” it as far more pleasurable to play…

And that’s why .. you can never achieve ultimate performance, and playability from a fingerboard that has not been leveled..

Fret leveling is the single most notable "mod" one can have done to their guitar....


R

I agree. A well-leveled fingerboard/fretboard/fret system plays and feels great, giving one the feeling of confidence and joy when playing.

But let's keep in mind, a very important reason to level frets is to minimize string buzz and choking. Frets are only "level" until relief is introduced to the neck - which throws much of the leveling process out the window, BUT it helps with minimizing buzzing/choking. Because of this change in neck geometry when relief is introduced, I feel proper shaping and crowning of the frets is imperative. If your frets are crowned too flat (shallow?), they may be perfect with a level neck, but start to be problematic if you use much relief, or if your neck tends to wander a lot. I think the crowning process is at least as important as the leveling - and more difficult to master.
 

Thebluesman

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I agree. A well-leveled fingerboard/fretboard/fret system plays and feels great, giving one the feeling of confidence and joy when playing.

But let's keep in mind, a very important reason to level frets is to minimize string buzz and choking. Frets are only "level" until relief is introduced to the neck - which throws much of the leveling process out the window, BUT it helps with minimizing buzzing/choking. Because of this change in neck geometry when relief is introduced, I feel proper shaping and crowning of the frets is imperative. If your frets are crowned too flat (shallow?), they may be perfect with a level neck, but start to be problematic if you use much relief, or if your neck tends to wander a lot. I think the crowning process is at least as important as the leveling - and more difficult to master.


leveling the frets ..+maintaining a radius is 1st hurdle
Crowning..without losing initial fret height [the level itself]..is the 2 nd hurdle.

one only knows if all l and c steps have been completed without error etc..when the guitar is now played etc=no buzz.
 

Boreas

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leveling the frets ..+maintaining a radius is 1st hurdle
Crowning..without losing initial fret height [the level itself]..is the 2 nd hurdle.

one only knows if all l and c steps have been completed without error etc..when the guitar is now played etc=no buzz.

Agree. This is where a good set of eyes and experience improves the outcome! But most people can perform an "acceptable" l/c/p on their first attempt if they do their research and work slowly and carefully. Many players won't notice the difference between and "acceptable and "premium" job. Even a simple polish alone can improve most fretboards!
 

Thebluesman

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a few extra strokes with the the beam or stone for a subtle slope/angle /fall away.. at the heel.[last few frets etc],,gives extra 'clearance' for the underside of the [vibrating] string to fret top
more commonly seen/done on acoustic gtrs.-less common on solid body guitars.
 

Freeman Keller

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Why would an acoustic/set have a hump by design? Doesn't seem like a feature for a good action. Tell me more.

Several people, including thebluesman have commented on this but here is one way to look at it.

Lets start out with a perfectly flat neck. On most acoustics the neck is about the same thickness from nut to the heel, then suddenly it gets very thick. They truss rod also typically stops somewhere in the neck heel. The body joint is typically at the 12th or 14th fret and there is a bit of fretboard that extends above the joint to the soundhole.

Let string tension pull some bow into the neck, it will look sort of like this

Neckprofile.JPG


When we measure relief on an acoustic guitar we hold the string down at the first and 14th fret, we forget about the section above 14 because its not part of the bowing.

If you "fret" the string in the picture above you will see that as you approach the body/neck joint the string is getting awfully close to the little bump - that is why too much relief will give you a guitar that buzzes at that transition. You need some relief for the area towards the nut, too much makes it buzz at the joint.

There are some things you can try to do with this. The first is to try to gain a little more of a gap at the 14th fret - that is the common place to use a fret rocker and you will often see the 13th and 14ths and 15th frets pretty heavily filed. The builder can do some things with the fretboard extension. Ideally you sand it flat as a continuation of the rest of the neck. Here is an acoustic guitar with the neck in place but no fretboard - I am sanding the top to be at the same angle as the neck is set (there is some sandpaper stuck to the underside of the level)

IMG_5017.JPG


It is acceptable for the fretboard extension to "fall off" slightly from the 14th fret to the soundhole. That will create increasing high action in that region of the neck, but it won't buzz (and lets face it, very few acoustic players ever go above the 12th fret). The worst situation is if the extension has a little "ski jump" towards the sound hole, that can create buzzes when you play in the upper neck.

The last two things that help are to start with the fret plane as perfect as you can get it and to run the minimum amount of relief that gives good clean playable action in the lower part of the neck.
 
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Freeman Keller

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A screw on neck should never have body hump/fall away issues but the OP's Gretsch clone is probably a set neck and could very well have them. The only way to tell is to take some careful measurements before starting any work. Don't do anything until you have measured everything.
 
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ghostchord

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Random musings and maybe some food for thought re: the fingerboard, vs. frets, notched or un-notched straightedge etc.

  • Surely everyone here has seen scalloped fretboards... How would you use your notched straightedge on those?
  • That said, the notched straightedge is the "standard" for whatever historic reason. People like following standard stuff that works. Hopefully the purpose of getting the neck flat is clear to everyone, imagine "levelling" frets on a bowed neck.
  • It seems like getting the top of the frets as straight/level as possible is a better recipe for removing less material during the leveling process. It might be hard to judge if the frets are all over the place but if your starting point is a flat fretboard and you insert the frets consistently I believe some builders find they don't even need to level at all and the difference between those different methods of getting the neck approximately flat are probably smaller than the error of either methods.
  • If I had an accurate enough 3d measurement system I would optimize for minimizing the amount of material that needs to be removed from the frets. Not for a the straight fretboard as the starting position. So I think fundamentally the less traditional method here is an improvement (assuming you are able to measure accurately enough to minimize that error). Since it's also cheaper it's a win-win ;) What you want is as perfect of a surface on the top of the frets with the minimal amount of material removed. The more material removed, the sooner the guitar will need re-fretting.
  • It's very unlikely the top of the frets remain parallel to the fretboard after the levelling process because your beam is riding on the top of the frets and has no reference to the fretboard surface itself. We're generally talking minuscule errors but for what that's worth.
  • When I play guitar generally my fingers don't touch the fretboard. When I fret a string generally the string does not touch the fretboard either. When I move my hand up and down the neck it also has no interaction with the surface of the fretboard. You might occasionally make contact with the fretboard while bending. However, a nice flat, shiny fretboard looks great. A flat fretboard yields flat frets (assuming consistent insertion) so by all means make the fretboard nice and flat (well, radiused ;) ). Unless you like it scalloped that is...
  • After we level the frets we intentionally introduce a relief (usually) and also since we level the frets when not under string tension they're certainly not going to be level (in one plane all the way down the neck) under tension.
  • What matters the most is fret to fret, if you're checking all the way up and down the neck with a fret rocker then your frets are level (to within the error detectable by this method which is "I donno" microns) and then as you keep walking away from your point of origin you accumulate some more.
  • I don't think temperature is a significant factor in the physics of leveling. Things like your technique, how flat/uniform your sandpaper is, how flat your beam is, how parallel you are to the strings, different "give" in the wood under the weight/pressure of levelling, are almost certainly larger contributors to error.
  • I definitely feel the profile of the frets when sliding over them when playing a guitar. I doubt my hand is capable of feeling minute fret height variations. As you slide your finger is bending the string towards the fretboard under pressure so you're always going to be going up and down, you don't slide at a level.
  • I also feel the smoothness of the top of the fret or lack of when bending.
  • Another thing I'm sure all of us feel is the ends of the frets as we move a chord grip up and down the neck.
I never bothered to look into the details of what PLEK do exactly... getting more curious, maybe I'll go check out some videos...

EDIT:





So IMO the coolest is that you can measure the profile under string tension. By the way, their claim that it's 1um accurate is total BS in my opinion. No way that sliding probe is actually accurate to 1um. Maybe it's the readout resolution or something. Not that 1um accuracy is needed for this process. The videos show some readouts from real world guitars which is cool.
 
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Thebluesman

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to be aware of;-temperature affects.temp fluctuating does/will affect...the lower the action the more obvious temp fluctuation will be.especially on acoustic gtrs etc.=use of summer/winter saddles used etc...
 

goodguy

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Tools for Neck Leveling/crowning:
Note: * if you only need a spot level

1) Straightedge (Taytools 108505 18”)
2) Notched Straightedge & Fret Rocker (Neck Check Guitar) *
3) Z-File Original (Stewmac) *
5) FretGuru 2 *
6) 16x2x1 Quartz Sanding Beam (free piece from local granite supplier)
7) Blue Painters tape *
8) Roll 3M 220grit rubber-back sandpaper (for beam - superglue this to painters tape stuck to beam edge = removable)
9) 10pc Diamond Needle File Set (harbor freight) *
10) Sharpie Marker *
11) Napatha *
12) Cotton Balls *
13) 800, 1500 wet dry sandpaper *
14) Flitz Metal Polish *
15) Superglue
16) Truss rod tool *
17) Neck support *
18) Desk mat/towel *
19) Worklight *
 
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