To lower the nut or file the slots down ...

Choweet

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... THAT is the question. lol

Which do you guys prefer? I have absolutely no idea how much to file each slot down unlike the pro luthiers I see in ukulele setup videos so I usually just bang the whole nut off, file the whole darn thing, and then replace. This method never gets me perfect intonation, but I'm always very close, maybe 1/10th or 1/5th off from the note which I consider good enough since I only do setups on cheap ukes.

... And if any of you guys could point out how to properly file each nut slot down that'd be awesome! Thanks. :D
 
Make another nut to gain the experience. Simple needle files and sandpaper on a hard flat surface. You can put the original back on the uke if necessary.
 
I have a set of automotive "feeler" gages that I use. You can buy a set for under $5 at a local auto parts store. I have found that most all ukulele frets are about .035" inch high above the fingerboard by using these gages. To file the nut slots down, I usually add .005" to the .035" and file the nut slot down so the bottoms of the slots are .040" above the fingerboard. This gives about .005" clearance for the strings over the first fret.

To file the slots, use .040" worth of feeler gage, place the .040" worth right up by the nut, and file the slots down one at a time until you get to the feeler gage. It is not necessary to remove the strings when you do this.

Hope this helps.
 
I have a set of automotive feeler gages I use to check the height of each string. I have a light/magifier on a stand I look through. You just loosen the string file some, replace the string, get tension on the string and measure, and repeat as necessary.

Nothing wrong with sanding the entire nut down, just need to make sure you keep it at 90 degrees from vertical. I'll temp super glue the nut to a block of hard wood that I have cut and verified as 90 Degrees. I leave with the portion I want sand off exposed. I then use the block to ensure I don't tilt the nut base while sanding.

I bought a set of these nut files 4 or 5 years ago for 70 or so bucks and they have paid for them selves many times over.

http://www.warmoth.com/Nut-Files-Set-of-8-P45.aspx

They also have this set http://www.warmoth.com/Nut-Files-Set-of-3-P44C215.aspx

I bought one of these calipers from Harbour Freight on sale for $5 to measure the string width and nut height, it comes in handy,

http://www.harborfreight.com/6-inch-composite-digital-caliper-93293.html


Nut Angle.JPG
 
If you do not have files knock off the nut and sand the bottom on a flat surface with sandpaper on top...with needle files you eliminate have to reglue the nut...much easier to me..
 
I have found that most all ukulele frets are about .035" inch high above the fingerboard by using these gages. To file the nut slots down, I usually add .005" to the .035" and file the nut slot down so the bottoms of the slots are .040" above the fingerboard. This gives about .005" clearance for the strings over the first fret.

Wow, was I under the wrong impression! I thought the bottom of the string should be about 0.8 mm (.032" or about the thickness of a credit card) over the first fret. You're saying .005" over the fret, which is a couple of pieces of paper. Here I, not knowing any better, thought my uke was set up not too badly for an entry level. What clearance do you shoot for over the 12th fret?

Jim B
 
Don't worry about measuring clearances over a fret - let your ears or tuner tell you when nut slots are low enough.

You should be able to fret each string at the first fret without the note pulling measurably sharp. Note that "normally" means just behind the fret (not next to the nut) and just hard enough to get a clear note. With the tall frets they tend to put on ukes these days you will be able to pull even a properly setup uke sharp if you put a death grip on the string.

I.e. if the E string is tuned spot on, then when you fret at the first fret you should get a spot-on F. Typical factory ukes (Kala, Lanikai, etc) often pull anywhere from 5 cents to 20 cents sharp. Work each slot down very slowly (a nut-slotting file is best, but a welding torch cleaner can be used if you're not planning on doing very many ukes over your lifetime). Avoid the small triangular "jewelers" files - the shape of the slot they make is very poor. String height will vary drastically with minor changes in string diameter and when the string is pulled down into the sharp "V" under tension it will tend to make the string want to stick and not tune smoothly.

Ramp the slot down slightly toward the tuners, this ensures that the string will "break" cleanly right at the fretboard-facing edge of the nut. If you file the slot straight or, heaven forbid, sloping down towards the frets, you will probably not get the best sustain and you may even have intonation issues (which is the very thing you're trying to correct). BTW, StewMac.com sells nut files - they're quite expensive but for most uke work you can get away with just one "double" file - the size where one side is .026 and the other is .032 has been all I've ever used on ukes in spite of the fact that I own a full set of the files.

You should work each slot down just far enough that the fretted note is not sharp. When you reach that point stop, and don't worry how high the string is above the first fret. I can honestly say I've never measured the height of the string over the first fret. Ever. If you go too far (the string starts buzzin) you can use a bit of Nailaid Maximum Iron Hardener (nail hardener) to build the slot back up. If you've been working down slowly just one thin coat will probably do. The hardener will feel dry in a few minutes but let it cure for at least several hours (preferably overnight) before putting a string back in the slot. It takes several hours for the hardener to fully cure.

If you have one or more strings that you can't work down far enough to get perfect intonation at the first fret without buzzing then you have other issues. The bridge saddle may be too low, or the frets may not be even. If the action is very low over the 12th fret you can probably replace or shim the bridge saddle. If the action over the 12th fret is not very low then you have a decision to make. You can either level the frets or use the nail hardener mentioned above to raise the slot high enough to make the buzz go away.

Many folks are happy if they get the intonation at the first fret within about five cents without buzzing. I used to be (there was a time when I was happy with 10 cents, actually). However, the more you play, and the better intonated the instruments are that you play, the better your ear will become and the less tolerance you'll have for intonation issues. I can't really deal with five cents any more. There are certain first position chords that will drive me nuts if a string is off by more than a couple of cents.

Since most players spend a lot of time at the first postion I consider intonation at the first couple of frets to be the most critical aspect of a proper setup. Well, second only to the uke should not buzz when played normally, obviously. When you get the action low enough to get perfect intonation at the first fret, you'll coincidentally have a nice low action that will make that Bb, for example, much easier to finger.

My second step in a setup is to lower the bridge saddle until I am comfortable with the action up the neck - or until a string starts buzzing.

So, to summarize in order:

1) Work the nut slots for perfect intonation at fret 1
2) Work the saddle until happy with the action up the neck (12th fret and beyond)

If you encounter buzzing:
3) If the action up the neck is quite low, raise the saddle.
4) If the intonation is perfect at the first fret, see if you can raise the nut slot without introducing an unacceptable amount of intonation problem at the first fret.
5) If 3 and 4 aren't acceptable (i.e. the action is already fairly high or the intonation at first fret is already less than perfect) - you need to level the frets, and that's a whole 'nuther post.

John
 
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Oh, BTW, to actually answer the OP's question :) I don't recommend filing the bottom of the nut for three reasons.

First, you usually won't be able to get perfect intonation on all strings without one or more of them going too low and buzzing. Each slot needs to be worked just low enough to get perfect intonation. So, if you work from the bottom of the saddle you will usually have one or two strings where you haven't achieved perfect intonation or one or two strings that are buzzing.

Second, if you don't file the bottom of the saddle absolutely, perfectly, level you will adversely affect sustain. If you get it really unlevel you may even introduce "rocking" that will adversely affect sustain and make string height not perfectly repeatable because the nut can "roll" side to side when you are changing strings or what have you, raising some strings and lowering others.

Third, working from the top you don't have to unstring the uke, you can simply lift a string out of the slot and pull it to the side while you are working on the slot.

I know some people have successfully set up ukes working from the bottom of the nut. But it takes an extreme amount of care for the second issue and the first issue becomes purely a matter of luck (i.e. you might get lucky and end up with all strings perfectly intonated but it's not assured).

John
 
Holy ba-jeebus thanks for all this advice!!! I thought I had to lower the nut if I was having buzzing/intonation up fret 3! I'll try only going up to fret 1, and fixing the saddle for any fret afterwards on my next setup.

Definitely adding an automotive feeler gauge on my shopping list!

@Olde - What note should I be aiming for on the first frets on the strings? I never tested intonation down the neck, just at the 12th fret I only checked for buzzing down the neck. I know this sounds like I'm promoting shoddy setups, keep in mind I've only done my setups on sub 100 dollar ukes.

@UkuleleBlues - I only use 0.026" for my G and A string and 0.032" for my C and E strings, isn't that good enough? Just curious. Thanks for that diagram, I wasn't aware rounding of the nut was another problem, hasn't happened to me yet, but I'll sure watch out for it!

Seriously guys, thanks for all this advice!
 
John, excellent information, thanks!
 
Be aware that once in a while, depending on the nut material, they will crack/break while filing (personal experience with a Corian nut).
 
There's another way to use the feeler guages that I learned in Dan Erlewine's "Guitar Player Repair Guide". Stack the feelers at the face of the nut until they match the current slot height. When you place your file in the slot and file stop when the file just contacts metal. That's your current height. To lower the slot just remove the appropriate guages and then file and when you hit metal stop! Example: remove a .010 guage and file until you hit metal again. You've lowered the slot .010. This removes the danger of going too deep with the slot and ruining the nut.
 
There's another way to use the feeler guages that I learned in Dan Erlewine's "Guitar Player Repair Guide". Stack the feelers at the face of the nut until they match the current slot height. When you place your file in the slot and file stop when the file just contacts metal. That's your current height. To lower the slot just remove the appropriate guages and then file and when you hit metal stop! Example: remove a .010 guage and file until you hit metal again. You've lowered the slot .010. This removes the danger of going too deep with the slot and ruining the nut.
Nice tip. I've screwed up a lot of Nuts by filing too deep.
 
Wow, was I under the wrong impression! I thought the bottom of the string should be about 0.8 mm (.032" or about the thickness of a credit card) over the first fret. You're saying .005" over the fret, which is a couple of pieces of paper. Here I, not knowing any better, thought my uke was set up not too badly for an entry level. What clearance do you shoot for over the 12th fret?

Jim B

I think that WDS means is that when you press the string down at the third fret you'll then see .005 clearance at the first fret.
 
Is this the feeler gauge I need?

http://www.ebay.com/itm/LISLE-TOOLS..._Automotive_Tools&vxp=mtr&hash=item4843f5784f

If so, I don't quite understand how to use it. Can someone please explain?

A feeler gauge is used to measure the clearance between two objects. Mechanics use it to set the clearance between valves and rocker arms and to set the gap on spark plugs.

Each blade has a specific thickness marked in inches and millimeters. For example (in inches) you might have blades of .002, .005, .020, .034, etc. You can combine (stack) blades to get a thickness you might not have in a single blade. Combine a .003 and a .015 and you get a thickness of .018.

It would be impossible to accurately set thicknesses this small with a ruler. See attached pic on how to use one on your uke. Just make sure when measuring you don't raise the string with the gauge, it should just barely touch it. Also be careful to keep the blade parallel with the string and fret (2 directions) so you get an accurate reading.

Hope this helps

Feeler Gage.JPG
 
My husband is far more handy than I am, but he managed to frak up the nut badly on the Kala uke. Kala has precut replacements, but do they ship outside the US? Why no, of course not, international customers know what they can go do with themselves.

So I guess I have a wall hanger now. Local luthiers cost too much for a uke like this, and obviously we don't know what we're doing well enough to use a blank nut. :(
 
Wow, was I under the wrong impression! I thought the bottom of the string should be about 0.8 mm (.032" or about the thickness of a credit card) over the first fret. You're saying .005" over the fret, which is a couple of pieces of paper. Here I, not knowing any better, thought my uke was set up not too badly for an entry level. What clearance do you shoot for over the 12th fret?

Jim B

I don't have a precise number to give you for the 12th fret. I just take the saddle out and sand the bottom off until the action gets down low without buzzing. I never measure up there like I do at the nut.

Back to the nut and the .040". I gage how well an instrument plays by how easily I can bar the first fret with my index finger. You should be able to easily bar the first fret if the strings are down low enough.
 
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