Hi, thanks everyone for your help and advice in the past. I searched for discussions on this topic and still thought I might get some new insights if I created my own post.
I've done a few refrets and have been trying to understand how to get my guitars set up better in general. Much of my information has come from Dan Erlewine's videos and his book Guitar Player Repair Guide.
I heard Dan say repeatedly that he prefers a "straight neck" and that he's not a big fan of relief, so I simply aimed for dead-flat necks on my guitars. I ignored the idea of any relief, however slight.
Now I'm thinking that a little relief may be an important missing element in my set ups. I found a discussion of acoustic guitar set up which got me thinking. It is from someone who appears to be a hobbyist, however it seems well-thought-out to me---http://thbecker.net/guitar_playing/guitars_and_setup/setup_page_01..... I want you guys' opinions, though because I'm still trying to wrap my mind around how all the factors contribute to the overall set up and visualize what's going on.
Becker's method is basically setting in the desired amount of neck relief first (he recommends .010"), then setting the saddle height with a capo on the first fret, and then filing the nut slots down.
Erlewine recommends cutting nut slots with the neck adjusted dead-flat, so that relief can be added if desired, as opposed to cutting them with relief, and running the risk of someone coming along later and straightening the neck and finding lots of buzzing. So, a dead-flat neck requires the nut slots to be slightly higher to achieve the same action at the first fret, right? This seems logical. And a relieved neck with "X" clearance at the first fret will have slightly higher action at the 2nd, 3rd, 4th frets, etc. than a straight neck with the same action at the first fret. Is this correct?
As I imagine the path of a vibrating string plucked open or at the 1st or 2nd fret, the idea of relief makes perfect sense to me, as the fretboard could theoretically be made to follow as closely as possible just outside the "cigar-shaped" area (term I read on the forum somewhere---this would be a long, thin, pointy-tipped cigar) through which the string vibrates. The frets would follow the underside of the "cigar" beginning at the tip near the nut, and when reaching the midpoint of the cigar, would no longer follow back up, but remain level to the end of the fingerboard (or fall slightly away at the tongue).
I still am not sure how to visualize how a relieved neck relates to the path of a vibrating string as you move up to the 4th, 5th frets, etc. I do see that on most guitars, the action is lowest at the nut, with the strings rising away from the frets slightly as they move toward the bridge. It makes sense to me that relief mainly serves the purpose of reducing buzzing in the lower frets, as the higher frets are less susceptible since they must be pressed further when fretting, with the vibrating portion at a safe distance from the higher frets. So, in the "flatten-out area" as Dan calls it (frets 9 or so and up), I understand that buzzing would be less likely, but what about the area between the low frets and the beginning of the flatten-out area?
Is there a general consensus about relief vs flat necks? Are certain tradeoffs inevitably involved, etc.? If I imagine the "cigar" shape in relation to a flat neck, it seems that a higher saddle would be required than when the neck has relief, as a cigar whose tip is at the nut would have to be upturned away from the fingerboard (like if you had a pointy-tipped cigar, or a toothpick, etc. resting on a surface and you press one end down toward the surface, the other end is lifted up). Is this correct? Can I assume that Dan plays with a very light touch? Otherwise I'm not sure exactly why he prefers no relief. I also play pretty lightly in general (kind of James Taylor-style fingerpicking and light strumming, no single-note solos up the neck on acoustic--I'd also like to leave some room for strumming with a pick, though I'm never too aggressive), so I figured I'd go for a very small amount of relief to get my ideal playability.
I would love to hear anyone's thoughts on all this! Sorry it was so long---hopefully someone reads it.
Sorry, misread concerning adding .001" string to string.
Still, when you fret at the first there is a specific gap at the second. If you duplicate that gap open string to first fret, instrument will play the same open or fretted at the first, regardless of relief or saddle height. Any additional height makes it stiffer at one with no advantage I can see. Why do you need more clearance at low E when any advantage disappears when you fret that string?
Fretting at the first fret and measuring at the second gives you a dimension that is variable, depending on where relief and saddle height is. That can change with humidity swings, doesn't make sense to me but if that is working for you, great.
Consider the low E string scenario that is .005" higher than the high E. Which will wear the slot faster? Obviously, wound strings will abrade quicker. If everything else is ideal down stream, frets, relief ect. and say I do get the wound strings to behave and not buzz when set the same as the treble E, how long will it stay that way? If it was for me and I wanted to split hairs unnecessarily, that would be my choice. When I do a set up for someone that is paying me to do so, then they should get a set up that has some wiggle room for wear.
I would be curious to have you measure one of your guitars, fretting between the 3rd and 4th frets, holding that and then measure with a feeler gauge from the top of the first fret to the bottom of each string and tell me what values you measure with this method.
Thanks, Paul. Can you explain why you fret between the 3rd and 4th frets? This is the point in a setup when most others fret between the 2nd and 3rd frets, aiming for a minimal clearance between string and first fret, isn't it? Is this a unique way of taking this measurement?
Russell, I adopted and adapted this method years ago from one of Don Teeters books. All that really matters is a repeatable way to the same end. I arrived at my values from repetition and documenting results from each project. The same could be done fretting 2 - 3 I suppose but the spaces that way are tiny to almost not there and would be more difficult to measure accurately with feeler gauges.
I should have also mentioned that these days not only is player style important to understand for set-up purposes but alternate tunings too.... We have clients who like low C.... and we need to know this to set up their ax properly.
For cutting nut slots we seem to be doing it a bit differently than some of the things that I have read here. By no means am I suggesting that what we do is better, just different.
1) Set relief for now, this is not necessarily the final relief but in the ball park to prevent cutting the slots too low if the relief is excessive.
2) Tune to pitch before step one above and after too.
3) We start with the high e because that's the toughest one to do for us or for me in terms of being able to see what I am doing. They don't call me blind mellon Luthier for nothing ya know...:)
4) While fretting and holding between the 2nd and 3rd fret we tap the string on top of the first fret crown. We are examining the clearance (if any.... the slot can be too low). For us it's not a measurement but going for the smallest clearance that we can achieve with still no contact when holding the string fretting between the 2nd and 3rd. The distance is so very small and we have measured it in the past because we wanted to know that it's often around a thou or less of gap for the high e.
Of course one swipe of the file too far and you are getting to practice your dentistry skills with our UV cured composite dental filling that we use to build up low slots....
The b string is similar and with each string the space when fretting and holding slightly increases. The low e will have the greatest clearance.
There are other considerations such as how a string will ark over the break point of the nut. What this means is that it's possible to cut a nut slot lower than the first fret and still not have any buzzing or contract when it's played open. Slot heads and designs with more break angle also can create more string ark over the first fret.
Back to alternate tunings. Alternate tunings can greatly impact how a string arks over the nut slot and that's why it's also important when tuning to pitch to tune to the alternate tuning that the player uses the most or has the least.... ark out of the nut slot.
The goal with cutting nut slots of us is player comfort AND eliminating any need for any of this snake oil such as nut compensation. It's our experience that if nut slots are cut very well nut compensation does nothing of value that cannot be achieved simply by setting up the nut slots properly in the first place. I know this will miff some but that's our experience.
The most common thing that we see with set-ups done elsewhere is the nut slots are never cut as low as they can and should go... The down side is more effort required to play AND the tendency to pull notes sharp as well.
Also for us and something that helped me personally tremendously to learn how to do this stuff is that the nut slots can be done early on after setting relief and then what remains is saddle height and the proper radius for the saddle(s) simplifying the process and eliminating the variable of the nut slots early on.
On another forum I had a Luthier who has done this for three decades tell us that he uses the nut slots to set the action... I argued that nut slots should be independent of action adjustments because as above the slots should be cut for optimal comfort and minimal pulling of notes sharp. Sure nut slot depth is a function of existing action but for setting up a guitar, etc. we believe that the slots can be addressed first and independently of saddle height. Go figure...
Hey Andrew - For us cutting the nut slots is not a hard measurement but a visual thing. What we are looking for is the very small space and even a sliver of light for the high e and b strings. It's so very fine that I have trouble seeing and am grateful when I hear the "tink" when I fret and hold between the 2nd and 3rd and tap the string over the first fret crown.
Dave has measured it though before and it can be around half a thou for the high e string. The thicker the string the more clearance with the high e being the least clearance and the low e being the most.
I'm the sort who is driven by methodology and wanted a system if you will for set-ups. Learning to set relief and do the nut slots first was much easier for me and the results are excellent too because the nut slots are an important variable to set-ups and eliminating this variable up front does indeed simplify things as you rightly mentioned.
Yep the arc is also a function of tunings, string diameter, string brand (some strings are stiffer). We can and do work in the strings to minimize the arc as Richard mentioned but tuning will and does pull the string through the nut slot exposing string at the nut face that has not been worked in until it is played and worked in.
This arc that I speak of can be witnessed when we back file a low nut slot. By increasing break angle we also increase the arc of the string.
It's been our experience that many Luthiers don't cut the slots as low as then can go. In fact one of the ways that we determine if we did the work on an instrument is the nut slots. In our area no one else is cutting them as low as we are making it a signature of sorts.
Dave has been studying and doing experiments with intonation and as mentioned we are not fans of nut compensation and instead believe that the root cause why many rely on nut compensation is that their nut slots are too high and fretting pulls things sharper than it would with a properly cut nut slot.
I also wanted to relate some personal experiences times several thousand clients. Call us gluttons for pain but we guarantee our work 100% and as such it's super important to us to 1) do it right, 2) provide real, measurable value to our clients and 3) ensure that our clients are actually happy as a clam with our work.
As such when they pick-up their instrument we ask them to play it and be sure that they are happy. We tell folks every day if you are not happy you don't pay.... So far no one has ever taken us up on the guarantee but we have proactively sent a check to one client along with a letter detailing why they are no longer permitted to come to our business.... One out of thousands is not that bad...:)
Anyway the very first thing that our clients notice is the nut slots but not the slots themselves but how the instrument plays super easy in the cowboy chord region. Then, when they have the ability, they may check out the rest of the neck as well.
What we hear comments on the very most is the ease of playing after one of our set-ups and that my friends is largely due to very low cut nut slots.
Nut slots are one of the simplest things that we can do for our clients that they will notice and appreciate. There is some risk of cutting too low and I do it likely once a week and then have to do a quick UV cured dental fill. If we did not have a very good solution for a low nut slots it's likely that I would not be going for that last couple of thou when cutting the slots. Safety nets are nice to have...:)
You can minimize that "arc" by pressing the string down on the playing side of the nut - called setting the witness point. But on heavier strings, especially on a bass, you can't flatten it out totally. Regardless, setting the witness points at the bridge and nut will have a significant impact on intonation. Helps to stabilize tuning as well.
Yeah, that seems simple enough. It makes more sense to me to "set the witness point" as you called it than to factor the "arc" into the cutting of the nut slots (on a guitar).
Ok, that's good to know. Fortunately I'm only setting up for myself at this point.