The Acoustic Guitar Forum

Go Back   The Acoustic Guitar Forum > General Acoustic Guitar and Amplification Discussion > Build and Repair

Reply
 
Thread Tools
  #1  
Old 04-16-2016, 02:54 PM
Tico Tico is offline
Registered User
 
Join Date: Feb 2016
Posts: 4,571
Default Selecting nut-slotting files

Stewmac sells 12 widths.
http://www.stewmac.com/Luthier_Tools...ing_Files.html

Here are the widths of the files in thousandths of an inch:
10 13 16 20 24 28 32 35 42 46 50 56

I don't wanna spend $165 for all 12.
This is a hobby not my profession.
I want to work on my own guitars which have lights or extra lights with the following gauges:
12-16-25-33-43-53
11-15-24-32-42-52

Even if I bought all 12 files they still don't all match the strings I use.

Whadyado?
Do you use, for instance, a 0.010 file for a 0.012 string but wrap the file in, say, 800 grit sandpaper?
Should the string fit tightly in the groove, or is it best to have, say, 0.001 of space on each side of the string?

IOW which files would you buy for ONLY the above string gauges?

Next, since the cutting surface is curved not flat I assume you could not save money by not buying a few sizes and instead clamping two smaller files side by side.
For instance ...

56 = 32 + 24
50 = 24 +16 + 10
46 = 20 + 16 + 10
42 = 32 + 10

Am I correct in assuming it's important the bottom of the groove is curved with a radius that matches the string for better contact and longer wear?

Last edited by Tico; 04-16-2016 at 03:08 PM.
Reply With Quote
  #2  
Old 04-16-2016, 03:12 PM
charles Tauber charles Tauber is offline
Registered User
 
Join Date: Feb 2011
Posts: 8,376
Default

This question comes up semi-regularly.

If you want to save money, buy a set of $10 needle files and a $10 X-Acto saw. You will then be able to accommodate all string gauges. I used those tools for more than 25 years quite successfully. Luthier's have used similar tools for generations.

Gauged nut files are a relatively modern invention. They are convenient and nice to have but not essential. They save time if you do a lot of this kind of work.

If you start trying to double up files to create wider slots you will negate the ease and speed that comes with using gauged nut files.

A narrow nut file can be angled side to side as you file in order to create a wider slot. However, if the file is significantly under size, that too negates the effectiveness of having a gauged nut file. It is then just as easy if not easier to use a needle file. Getting a gauged nut file to cut .005" larger than its size is pretty easy.

Opinions very on how important the shape of the bottom of the slot is. I have found no difference between a round slot bottom and a flat slot bottom.

For speed and ease of use, these days I prefer gauged saws, which leave a flat bottomed slot. Unlike files, saws cannot very effectively be made to cut a wider slot that it's blade.

From Stewmac's selection, for your string gauges, on a budget, I'd buy .020" and .025" saws and .035" , .046" and .056" files.

You might want to consider these: http://www.japarts.ca/Uo-Chikyu/Uo-C...s-Featured.asp

Last edited by charles Tauber; 04-16-2016 at 03:24 PM.
Reply With Quote
  #3  
Old 04-16-2016, 04:28 PM
Rudy4 Rudy4 is offline
Registered User
 
Join Date: Oct 2012
Posts: 5,172
Default

I've done hundreds of nut slots using only a German-made Blintz back saw that I purchased 30 years ago; it's somewhat comparable to the small X-acto hobby back saw.

I use only the fine blade that came with the interchangable blade set (somewhere around .015") and rock the blade to the side for wider cuts. All my slots are finished off by wrapping a sheet of 220 around the bottom of the correct sized strip of metal that works with the slot size I'm working with. The strips are available in finer hobby shops, and come in precise thicknesses. I keep a bunch of these handy, and even round the edges and mount them in handles to create "Special nut slotting tools".

The smallest slots are simply smoothed and rounded with a folded piece of 220 directly in the slot created by the back saw.

It might seem that a thinner saw is needed, but I've never experianced any difficulty with slot width, as the rounded bottom of the slot prevents the string from buzzing if there is sufficient back angle, which should be the case in a properly formed slot.

There are a lot of "specialty tools" being marketed to those who didn't cut their teeth on older methods. No problem with purchasing specialty products, but I feel it's far better to learn to use tools and techniques that are adaptable to many situations.

Many of the "specialty tools" elict amusement to me, as I see tools that were created for other purposes, re-branded as 'guitar tools" and sold at a substantial markup.

A luthier supply shop owner has to put food on the table somehow...

A final tip... Pay particular attention to ANYTHING Charles Tauber posts!
Reply With Quote
  #4  
Old 04-16-2016, 06:00 PM
Howard Klepper Howard Klepper is offline
Registered User
 
Join Date: May 2008
Location: Earthly Paradise of Northern California
Posts: 6,515
Default

The bottom of the nut slot should not be a semicircle the exact same diameter as the string. That will cause unnecessary friction when tuning. You really only need contact at the bottom of the string, and a slot that isn't flat on bottom so the string won't slop from side to side. The bottom of the slot can be a semicircle (or some other concave curve) quite a bit wider than the string and do that.

A knife edge needle file can do the plain strings from .010" to .017". As others have said, it's easy to add a few thousandths by tilting the file a bit from side to side as you cut.
__________________
"Still a man hears what he wants to hear, and disregards the rest."
--Paul Simon
Reply With Quote
  #5  
Old 04-16-2016, 07:22 PM
bnjp's Avatar
bnjp bnjp is offline
Registered User
 
Join Date: Nov 2001
Location: Knoxville, TN
Posts: 2,374
Default

I have the whole set, but the ones I use most are: 13 16 20 28 35 46 56
__________________
Bryan
Reply With Quote
  #6  
Old 04-16-2016, 09:26 PM
Nash Rambler Nash Rambler is offline
Registered User
 
Join Date: Oct 2015
Location: Los Angeles
Posts: 106
Default

I would go with - 20 28 35 46 56. Ideally you want the files to be at least .003" larger than the string.
__________________
______________________
Breedlove American Revival D/SS - Breedlove Oregon Revival D/SMY - Martin D12-28
Reply With Quote
  #7  
Old 04-16-2016, 09:57 PM
dhalbert dhalbert is offline
Dan - Charter Member
 
Join Date: Sep 2012
Location: Eastern MA
Posts: 1,643
Default

I bought these, which are cheaper ($54 for 6 sizes - 2 per file). They were fine for my amateur work. I could have used needle files too, and I respect Charles' comments. I do like having the calibration.

http://www.philadelphialuthiertools....e-set-3-files/
Reply With Quote
  #8  
Old 04-16-2016, 10:28 PM
Frank Ford's Avatar
Frank Ford Frank Ford is offline
AGF Sponsor
 
Join Date: Jul 2001
Location: Palo Alto, CA
Posts: 638
Default

As always, not the tool, but the technique. Whatever works for you to make the appropriate rounded slot is what you use. Me, I use five files plus the skinny saw blade for the smallest unwound steel strings.

Here's my current setup, five files joined at the hip:



Makes a nice one-handed tool, quick and efficient for me to get the job done:



The exact gauges aren't all that critical for me, as I use a "rolling" motion to widen the slot a bit as I cut it lower. With those blades, I manage to fit most any strings, up to mandocello. I rarely work on basses, so I'd probably reach for something bigger more often if I did.

Too often we believe the advertising that suggests you must have a specific tool to get a job done. . .
__________________
Cheers,

Frank Ford
Reply With Quote
  #9  
Old 04-16-2016, 11:31 PM
charles Tauber charles Tauber is offline
Registered User
 
Join Date: Feb 2011
Posts: 8,376
Default

Quote:
Originally Posted by Rudy4 View Post

A final tip... Pay particular attention to ANYTHING Charles Tauber posts!
That's very kind, but that's how I feel about Howard and Frank.
Reply With Quote
  #10  
Old 04-17-2016, 07:52 AM
LouieAtienza LouieAtienza is offline
Registered User
 
Join Date: Feb 2013
Posts: 4,617
Default

I also have a couple sets of the hardware store needle files. Between the 6 I've been able to do slots on electric and acoustic. I start the wound strings with a razor saw, and that saves my files and hand a bit of work.

I suppose if I did enough of these a gaged set would be nice, and Frank's idea is nice. Just wondering if you were able to use a regular HSS drill bit or had to use an endmill?
Reply With Quote
  #11  
Old 04-17-2016, 09:54 AM
redir redir is offline
Registered User
 
Join Date: Aug 2011
Location: Mountains of Virginia
Posts: 6,702
Default

After 20 years of using regular needle files I finally upgraded to diamond grit needle files. I still just use needle files.

I once read a very convincing article on the shape of the nut slot that suggested a square would be best especially considering someone who may use a Bigsbey or some sort of vibrato with a standard nut. A circle shape, the string, in a square slot will have only 3 points of contact (maybe even just two) and have less friction then a circular shaped slot that hugs the string all round.

Just thought I'd bring that up as a point of interest and discussion.
Reply With Quote
  #12  
Old 04-17-2016, 10:14 AM
rick-slo's Avatar
rick-slo rick-slo is offline
Charter Member
 
Join Date: Nov 2004
Location: San Luis Obispo, CA
Posts: 15,175
Default

Quote:
Originally Posted by redir View Post
After 20 years of using regular needle files I finally upgraded to diamond grit needle files. I still just use needle files.

I once read a very convincing article on the shape of the nut slot that suggested a square would be best especially considering someone who may use a Bigsbey or some sort of vibrato with a standard nut. A circle shape, the string, in a square slot will have only 3 points of contact (maybe even just two) and have less friction then a circular shaped slot that hugs the string all round.

Just thought I'd bring that up as a point of interest and discussion.
It's easier to sit on a mountain top than on a tack. The less the contact area the more pressure on those areas. Probably not the greatest idea. It will quickly wear the slot shape to a more rounded contour in any case.
__________________
Derek Coombs
Youtube -> Website -> Music -> Tabs
Guitars by Mark Blanchard, Albert&Mueller, Paul Woolson, Collings, Composite Acoustics, and Derek Coombs

"Reality is that which when you stop believing in it, doesn't go away."

Woods hands pick by eye and ear
Made to one with pride and love
To be that we hold so dear
A voice from heavens above
Reply With Quote
  #13  
Old 04-17-2016, 11:20 AM
LouieAtienza LouieAtienza is offline
Registered User
 
Join Date: Feb 2013
Posts: 4,617
Default

Quote:
Originally Posted by rick-slo View Post
It's easier to sit on a mountain top than on a tack. The less the contact area the more pressure on those areas. Probably not the greatest idea. It will quickly wear the slot shape to a more rounded contour in any case.
I would tend to agree with this. I aim to make the slots "round" them lube the slot with pencil graphite.

I don't know who may also do this, but I don't follow the headstock angle when slotting. I start off with a shallower angle at the break point and "round" the slot into the angle.

I believe I read Eddie Van Halen used squarish slots when he first started out, which helped him because he did a lot of dive-bombing with the trem bar, and it was a vintage trem at that. Floyd Rose didn't come around with his locking bridge until later, and even the Rockinger needed a good nut, because it was a behind the nut clamp.
Reply With Quote
  #14  
Old 04-18-2016, 08:56 PM
hello people hello people is offline
Guest
 
Join Date: Dec 2005
Posts: 809
Default

I just did some work on a friend's guitar which had really high action. High at the 12th...like a trapeze...and high at the nut too. So I lowered the saddle no problem. I lowered the nut by carefully sanding the bottom of the nut. No problem.

Then I thought, geez, those slots could come down a hair more each...so I got the 52 nut file and carefully filed a tiny bit...put the string back in place and now there's buzzing on the low E.

Talk about a fine line...I barely removed/ filed anything and it went from being clean to buzzing.

Have I widened the slot? What is likely here? It's definitely not touching any frets...it's a slot issue. Fretted at the fist there's no buzz. So it's in whatever I did with my minuscule filing.

Any tips on how to right the ship?

cheers
Reply With Quote
  #15  
Old 04-18-2016, 10:04 PM
LouieAtienza LouieAtienza is offline
Registered User
 
Join Date: Feb 2013
Posts: 4,617
Default

Quote:
Originally Posted by hello people View Post
I just did some work on a friend's guitar which had really high action. High at the 12th...like a trapeze...and high at the nut too. So I lowered the saddle no problem. I lowered the nut by carefully sanding the bottom of the nut. No problem.

Then I thought, geez, those slots could come down a hair more each...so I got the 52 nut file and carefully filed a tiny bit...put the string back in place and now there's buzzing on the low E.

Talk about a fine line...I barely removed/ filed anything and it went from being clean to buzzing.

Have I widened the slot? What is likely here? It's definitely not touching any frets...it's a slot issue. Fretted at the fist there's no buzz. So it's in whatever I did with my minuscule filing.

Any tips on how to right the ship?

cheers
Did you disturb the angle of the slot, or maybe reversed it slightly? Fret the 3rd fret. If there's still a gap between the string and first fret then you're probably OK and just have to adjust the slot .
Reply With Quote
Reply

  The Acoustic Guitar Forum > General Acoustic Guitar and Amplification Discussion > Build and Repair

Thread Tools





All times are GMT -6. The time now is 10:54 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2022, vBulletin Solutions Inc.
Copyright ©2000 - 2021, The Acoustic Guitar Forum
vB Ad Management by =RedTyger=