# Instruments and Equipment > Builders and Repair >  Best DIY tools for nut slot adjustments?

## Tobin

I've received and read Rob Meldrum's e-book on mandolin setups, and it's a great resource.  But here's my dilemma:  I intend to do some adjustments not only to the nut on my mandolin, but also on a tenor guitar which will be tuned to octave mandolin tuning (and thus requiring larger strings than it originally was setup for).  Both have bone nuts.

My mandolin probably doesn't need much deepening at all, but the tenor guitar will likely need to come down quite a bit, and then I'll have to dress the top.  Those slots are already pretty deep.

So I'm not just going to be making nut slots deeper, but wider as well.  The trick of using feeler gauges with notches seems like it would work for deepening a nut slot of that width, but might involve some butchery if used to widen a deep existing nut slot.  I suspect the result would be a sloppy mess, with the improvised saw trying to walk back and forth on either side of the slot.  Unless I widen the slot first with sandpaper (?), and then deepen it.

Also, I'd really like to get a proper half-round profile on the bottom of the nut slot, rather than a square profile.  Doing this with a notched feeler gauge doesn't seem like the best option (unless I maybe round the corners of the feeler gauges with a Dremel tool or whetstone).  But considering the number of string gauges I'll be working with, I can't justify buying professional nut slot files.

So does anyone have other suggestions on how to make a handy DIY nut slotting tool to widen/deepen the slot _and_ give it a radiused bottom?  I'm wondering if just using a short clipping of the actual string would work, maybe with some jeweler's rouge (or other suitably light abrasive).  Perhaps remove the blade from a small hacksaw and find a way to mount the string in its place?  I could see it maybe working on the wound strings, at least, although it might be really slow going.  Not sure I have any ideas on the smaller plain string slots, though.

Any ideas would be welcome.

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## Soundfarmer Pete

A cheap source for finishing nut slots is a set of welding nozzle files. For plain strings, an Xacto razor saw (typical model making stuff) is handy - cheap and available in various thicknesses...but take care with these as they`re pretty aggressive!
Check ebay  :Mandosmiley:

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## Timbofood

Jewelers rouge is used for polishing and is not that aggressive, the torch files are a better shot, I think.  But, work carefully.

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## Dr H

> Also, I'd really like to get a proper half-round profile on the bottom of the nut slot, rather than a square profile.  Doing this with a notched feeler gauge doesn't seem like the best option (unless I maybe round the corners of the feeler gauges with a Dremel tool or whetstone).  But considering the number of string gauges I'll be working with, I can't justify buying professional nut slot files.
> 
> So does anyone have other suggestions on how to make a handy DIY nut slotting tool to widen/deepen the slot _and_ give it a radiused bottom?  I'm wondering if just using a short clipping of the actual string would work, maybe with some jeweler's rouge (or other suitably light abrasive).  Perhaps remove the blade from a small hacksaw and find a way to mount the string in its place?  I could see it maybe working on the wound strings, at least, although it might be really slow going.  Not sure I have any ideas on the smaller plain string slots, though.
> 
> Any ideas would be welcome.


If you really want to do it right you need some gauged nut-slotting files in the size of the string-gauges you're going to use.  These are not cheap, but they are the right tool for the job, will give you a properly-shaped slot of proper size, and the hassle they save you -- especially if they save you from trashing a nut and having to make a new one -- may be well worth the price.

StewMac has these at about $13/per gauge, but if you decide to get these try shopping around eBay.  Something like these:

http://www.ebay.com/itm/Guitar-Nut-F...6#ht_534wt_701

...but shop around and you can probably find a better price.

I got a set of 10 from Japarts (through eBay) for about $80 (plus shipping), and they were the same files StewMac would have soaked me $130 for.

Or you could just buy the 4 (or whatever) files you know you need, but you're going to spend $40-50 for that, so buying a set is really a better deal if you think you might ever want to do another nut later on.

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Jim Garber

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## Soundfarmer Pete

Another DIY hint........If you know how much clearance you want above the first fret, simply select the appropriate blades on a set of feeler gauges and strap the gauges tightly on the neck next to the nut with rubber bands.....then file away until you hit the gauge.....

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## Jim Garber

> I got a set of 10 from Japarts (through eBay) for about $80 (plus shipping), and they were the same files StewMac would have soaked me $130 for.


I assume that *this set* is for guitar?  Or what about *these*?

Did you get yours as 10 for mandolin from that seller?

..................................................  ..................................................  .........................................

Never mind... I see:




> Not Finding What You Want?
> Uo-Chikyu Standard Series nut files are available in the thirty-four (34) gauges, from 0.009" to 0.135". If our pre-assembled sets aren't what you're looking for, let us know what is! For any number of files we would be happy to make a custom listing for you. NOTE: Do not buy one item and expect to get another. If we already list what you want, buy that item. If we don't have the item already listed, wait for us to make a custom listing for you.


What would be the rule of thumb for the right gauge of file per slot?

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## jim simpson

link for stewmac's nut files:

http://www.stewmac.com/shop/Nuts,_sa...ing_Files.html

I have lost my file that was gauged for A string. I use J74's (D'Addario) so I think I would order the #0827 for the A. 
I really need to add a couple more files to cover my guitar nut needs.
Here's the J74 info:

http://www.daddario.com/DADProductDe...e-d9e1c9521e61

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## bratsche

Well, I've got a similar project underway, only I have to cut the entire bone nut and saddle from scratch from blanks (for an OM conversion).  But since I only plan to do this once (and am dirt poor), there's no way I'm investing in a new set of files.  I've got the nut done, except for on-the-instrument fitting adjustments (which are a way off yet as I must finish the headstock conversion first!), and all I used so far was a sharp, narrow-pointed Xacto knife to slowly whittle the bone away.  I'll either use a rounded feeler gauge or old strings mounted in a jewelers saw to get the bottoms of the holes properly rounded, when the time comes.   Might as well use things that are already here...   I've made entire bridges and nuts before using only the Xacto knife, hobby sized files, and sandpaper.  Bone is a bit harder than ebony or maple, but the concepts are the same, so it'll just take a while longer.

bratsche

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Tobin

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## Rob Grant

I invested in a half dozen of those expensive nut files when I first became interested in this game. For some reason none of them are exactly the guage I currently use on my mandolins and mandolas. In general I "undercut" the slot with the closest file or saw blade I have to the guage and then chuck the string of the exact guage into a small jeweler's saw frame to make the final adjustments. Works a treat for me. This works particularly well with ebony and bone. Pearl can be a problem, but a tad of light cutting compound on the wire in the saw will assist the procedure immensely.

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Mandocarver

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## Fretbear

There is a type of file called a "pippin" which is teardrop shaped. I use it for all my nut and saddle work, it will serve you just as well along with a decent set of needle files. Save your money and increase your skill set.

http://www.lmii.com/products/tools-s...es/pippin-file

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## Shelagh Moore

I use a razor saw followed by a fine round needle fine to get the right slot profile.

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## Tobin

> But since I only plan to do this once (and am dirt poor), there's no way I'm investing in a new set of files.


That's pretty much where I'm at with it too.  I'm not looking to invest hundreds of dollars in tools.  I just need to do this once, but I need to accommodate 8 different string gauges.  Buying individual files for each of those would be absurdly expensive for my purposes.  I'm usually the kind of guy who would rather buy the right tool for the right job and then have it for future needs, but I just don't see myself doing a lot of setup work in the future.  This should hopefully be a one-time deal.




> all I used so far was a sharp, narrow-pointed Xacto knife to slowly whittle the bone away. I'll either use a rounded feeler gauge or old strings mounted in a jewelers saw to get the bottoms of the holes properly rounded, when the time comes. Might as well use things that are already here...


This sounds perfect, and is the same approach I think I'm going to use.  As long as I go slow, take careful measurements and lots of test-fits, it should fit the bill.  Thanks!

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## multidon

For wound strings you can use short pieces of the old strings as nut files. Round wound of course not flat! They aren't sharp enough to start from scratch but if you start the slot another way they will do a good job of the proper shape and profile. This trick will not work on the solid string slots unfortunately.

I also was reluctant to invest in real nut files because I too was only going to use them "just once" but I took the jump and I am glad I did with now over 30 string instruments in the house. It is rare that I have bought an instrument without having to tweak the nut. Many manufacturers (Fender being notorious for this) cut the slots so the nut action is high. This insures they won't buzz when being played in the store. But they are often too high at the nut for me at least to play comfortably. I have payed for the nut files many times over by avoiding trips to the repairman to do this. If you are inexperienced I recommend slow and careful a little at a time. It is easy to cut away but difficult to put material back after its gone! Feelers gauges are useful here. They are much cheaper at an auto parts store than at a place like Stew Mac. Stew Mac however does sell a handy little tool for not much money that will lift the string out if the slot so you can file the put the string back into the slot. The procedure would be lift out the string file only one or two strokes put the string back then measure with the feelers gauges. Keep doing this until you have the action you want. It is more time consuming this way but it makes it much less likely you will go too far. You can even stop and play test along the way.

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## Jim Garber

> In general I "undercut" the slot with the closest file or saw blade I have to the guage and then chuck the string of the exact guage into a small jeweler's saw frame to make the final adjustments.


 I can see how using the string in a jeweler's saw works nicely for the wound strings but not how it would work for the unwound ones.




> This trick will not work on the solid string slots unfortunately.


Whoops! missed this one. What do you use for those?

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## multidon

Jim I use either a .010 gauged Stew Mac saw or an x-acto saw which is ungauged but a little wider than the Stew Mac then just a small piece of 400 grit sandpaper folded in half. The fold is actually rounded enough to make the right profile and the sandpaper will also widen the sides slightly. I would say I did this before investing in files but I have used this method and it worked for me. Of course still the rule is work slowly and measure often.

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Jim Garber

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## thistle3585

Having a set of nut files also means that you buy less "beverages" because you loan them to all the other guys in the jam that don't want to buy them.  :Smile:   The other option is to buy a set and split them with someone else.  Literally split them.  Break them in half.  You don't need a full stroke to use them.

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## Jim Garber

Do you experienced folks build an angle into the slots on nuts and bridges? In other words, does the string need to angle back sort of parallel to the headstock angle and angled back toward the tailpiece? Is that too obvious?

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## Shelagh Moore

> Do you experienced folks build an angle into the slots on nuts and bridges? In other words, does the string need to angle back sort of parallel to the headstock angle and angled back toward the tailpiece? Is that too obvious?


I, at least, do angle my slots to get the proper bearing points for the strings and to aid correct intonation.

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## Fretbear

It's very important that you do for getting the proper contact point for intonation from the leading edge of the nut, and to prevent any sitar like buzzing. Sometimes you will start to get a buzz and think you have gone too deep, but it is just buzzing from not being properly ramped. That's when you develop courage (and experience), filing further even after you think you have already gone too far.

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bratsche

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## Tobin

> Do you experienced folks build an angle into the slots on nuts and bridges? In other words, does the string need to angle back sort of parallel to the headstock angle and angled back toward the tailpiece? Is that too obvious?


I'm quite obviously not experienced at this, but Rob Meldrum's instructions do say to file the slots parallel to the peghead, not the fretboard.  And it has a decent photo showing why.  From what I've read on frets.com, it suggests the same thing.

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## Dr H

> I assume that *this set* is for guitar?  Or what about *these*?
> 
> Did you get yours as 10 for mandolin from that seller?
> 
> ..................................................  ..................................................  .........................................
> 
> Never mind... I see:
> 
> 
> ...


My set has 10-files from 0.010 - 0.056.  I actually got them when I was working on a cuatro, but I didn't think of them as being specific to any particular instrument.  From what I've seen, once you get up into the wound strings -- from about 0.022 and up -- a thousandth of an inch one way or another doesn't make all that much difference.  When filing by hand you probably get off that much just from wobble, and you're still going to have a closer fit that if you use a generic, ungauged needle file.  Let's see... my set is:

0.010 / 0.012 / 0.016 / 0.022 / 0.026 / 0.032 / 0.035 / 0.042 / 0.048 / 0.056

Which meets most of my needs, since it's pretty rare I work on anything as large as a bass.  I might add a 0.009, and a 0.014 to that, eventually.

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## Dr H

> I invested in a half dozen of those expensive nut files when I first became interested in this game. For some reason none of them are exactly the guage I currently use on my mandolins and mandolas. In general I "undercut" the slot with the closest file or saw blade I have to the guage and then chuck the string of the exact guage into a small jeweler's saw frame to make the final adjustments. Works a treat for me. This works particularly well with ebony and bone. Pearl can be a problem, but a tad of light cutting compound on the wire in the saw will assist the procedure immensely.


I have some gauged razor saws, too.  I'd just warn anybody who's new to this task to be *really* careful if you're going to slot the nut with one of these saws.  It doesn't take more than a couple of pulls to cut the slot _too_ deep, and then you're in trouble.

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## Dr H

> I also was reluctant to invest in real nut files because I too was only going to use them "just once" but I took the jump and I am glad I did with now over 30 string instruments in the house. It is rare that I have bought an instrument without having to tweak the nut. Many manufacturers (Fender being notorious for this) cut the slots so the nut action is high. This insures they won't buzz when being played in the store. But they are often too high at the nut for me at least to play comfortably. I have payed for the nut files many times over by avoiding trips to the repairman to do this.


Multidon, that's exactly how I started out, and exactly why I finally went out and bought the right tools.  When I had a couple of guitars and a bass, I used to do DIY setups with whatever tools I could find in the toolbox in the trunk of my car.  Now I've gout a houseful of guitars, banjos, mandolins, charangos, tiples, cuatros, dulcimers, etc., etc., and I've worked on every one of them myself.  

Given that my local luthiers charge about $75-$100 for a basic 6-string set-up, my set of files had pretty much paid for itself by the time I set up my second guitar.

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## mandomedic

I've been using a set of Ibanez nut files http://www.ibanez.co.jp/eu/products/.../nut_fret.html for years. On mandolins and guitars they work very well. The fret files of the same set are worthless, but if you look around you can find these Ibanez sets..

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## kkmm

> simply select the appropriate blades on a set of feeler gauges and strap the gauges tightly on the neck next to the nut with rubber bands.....then file away until you hit the gauge.....


This is exactly how I filed the nut slot using the feeler gauges as nut files (thanks to Rob for his idea).
After using feeler gauges as nut files, I had the need to buy a rotary tool set (80 pieces total from Harbor Freight, for 30$). In this set there are a few pieces with the round tip (various diameter) that can be used as nut (SLOT) files. I used them on ukuleles, mandolins and guitars.
If I have to do this very frequently, buying the nut file set from eBay makes a lot of sense and makes the job a lot easier.
The method (in the quote) is still valuable to ensure the slots are filed down to the right spot.

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## Tobin

Well, I suppose I should update this thread.

Over the weekend, I adjusted the nut slots on the tenor guitar that I spoke of.  The plain (unwound) strings fit easily in the existing slots and I was happy with the height already, so no adjustment was needed there.  But on the wound strings, I was stepping up the gauge significantly for the lower (octave mandolin) tuning. 

So I just clipped off a couple of inches from the string, placed it onto the existing nut slot, pressed my fingertip over it, and gently rubbed it back and forth over the slot, holding it parallel to the peghead.  With medium pressure and easy short strokes, I started to see dust coming off the nut as the winding wore its way down into the slot.  I just kept doing it and checking it regularly.  It worked great.  The string now sits nicely in the slot, at the proper height, and with the perfect rounded-bottom profile to the slot itself.

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## Dr H

> Well, I suppose I should update this thread.
> 
> Over the weekend, I adjusted the nut slots on the tenor guitar that I spoke of.  The plain (unwound) strings fit easily in the existing slots and I was happy with the height already, so no adjustment was needed there.  But on the wound strings, I was stepping up the gauge significantly for the lower (octave mandolin) tuning. 
> 
> So I just clipped off a couple of inches from the string, placed it onto the existing nut slot, pressed my fingertip over it, and gently rubbed it back and forth over the slot, holding it parallel to the peghead.  With medium pressure and easy short strokes, I started to see dust coming off the nut as the winding wore its way down into the slot.  I just kept doing it and checking it regularly.  It worked great.  The string now sits nicely in the slot, at the proper height, and with the perfect rounded-bottom profile to the slot itself.


Nice to hear that some stories have happy endings.  :Smile:

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