Official Luthiers Forum!

Total noob question, but better to ask and learn than botch something up.

I'm working on understanding nut spacing better and determining the proper widths for the strings I have access to a good digital caliper and other measuring tools I just don't know how to determine accurate string spacing (formula wise).

My method till now was to measure 3mm (1/8") from the outside of the fretboard on both sides of my blank, notch the blank, then measure with the little string spacing rule that SM sells to find the measurements that allow the strings to fit properly on the blank. However the ruler is kind of a pain to use (for me anyway, YMMV) and I'm working on making and acquiring some better tools to accomplish the task more accurately and with fewer mistakes.

So what are some of your measurement formulas to determine spacing? Just looking for advice as I really want to improve my skills in this area.

Hi Dan, Not sure if you've seen this:


It's one way of doing this without measuring. See what you think.

cheers

There are no hard rules for string spacing and there really can't be either for a number of reasons.

First string spacing must take into account any radical fret end bevels that cheap arse f*ctories favor doing instead of using semi-skilled labor to preserve fret top surface and individually round off fret ends. If the bevel is inset too much, and they usually are, our outer E's and their spacing is dictated by the bevels. This, by the way dictates all other string spacing and again all because a radical bevel is less costly to produce at the f*ctory....

Next is consideration for the player. I made a nut last Friday for a guy who is 7' 4" tall and had hands like hams... He had purchased a Seagull with a pretty wide neck and now wanted us to make a nut that was even wider on the string spacing. This guitar had radical bevels but I was still able to give him nearly .080" of more outer E spacing. Players have preferences and when considering nut string spacing they are a consideration, always.

Although rare these days.... two schools of thought from the past with either equal spacing from string centers or string outer edges some still have a preference here. I made a nut for a Luthier some time back who was retired or would have done it himself but he liked what ever string spacing the SM rule does not do, I am forgetting at the moment, so that's what I made him.

I know that you included an accurate "YMMV" but I have to ask, what's a pain about the SM string spacing rule? If anything I use mine too much and it's become a crutch that lately I am trying to wean off of and only use it initially to mark spacing. What I've been doing is picking it up 25 times or so..... to check my spacing as I cut the slots.

Slots can be moved as we cut one way or the other and my goal is to do most of this by eye in the future after an initial marking with the rule.

Anyway no hard rules. Do what you want with consideration for the limitations of the instrument, desires of the player, and a shout out to convention too although convention is by no means containing any hard and fast rules.

Accuracy can be improved with the rule by checking often..... (and using it as a crutch...) and also sharpening your pencil prior to marking. Is the rule required? Nope, lots of nut slots were cut before the rule ever was available. Do I like it? Yep, maybe too much...

Perhaps a discussion with Mr. Breakstone and the others here as to how best to use the proportional layout rule from Stewart MacDonald or other tools for layout would be of benefit. I would enjoy reading more on proportional versus fixed layout and the tools used for each - we have a few customers that prefer fixed distance layout and that task of getting exactly the same center-to-center distance between strings is more difficult for me than proportional layout.

As to my experience with the Stewart MacDonald rule, I struggled with it for a few months, but less so now that I stopped doing any pre-shaping of the ends of the blank before marking the slot locations. It is also helpful to follow the advice in the usage directions to use a fine tip (0.5mm) mechanical pencil or scriber for marking. The scriber helps score the nut material, which makes starting the saw cut easier, but is, at least for me, more difficult to see on light-colored bone than pencil..

The other piece of advice I got about making nuts after ruining a half dozen blanks during my first few attempts was that the best shortcut to doing the job quickly and with good results is to do a few hundred first to warm up. I am still working on that!

_________________
A constellation only takes shape when one maps the whole.
- Beth Brower

Hesh, thanks for the advice, it is much appreciated.

My issue is that in using the rule I have a tendency to have the rule slip a little bit causing me to mis-mark a line or mark it crooked. Perhaps I should rephrase my question to be along the lines of "Are there better ways than the way I have been doing it?". And I do realize it might just be a user error thing. Never hurts to ask though.

What is frustrating to me is getting every line perfectly spaced, lined up, and then measuring again only to see that I screwed one up and thus have to redo the one line. Does that make sense? Perhaps I'm being too much of a perfectionist about it but I am trying to avoid becoming one of "those repair guys" who simply don't do a good job.

I love the SM nut measuring tool. It's one of my favorite and most use SM tools probably. I used to just do fixed widths until I got that tool and for me there is no going back, not so much because of the fixed width but just because of the ease of use of the tool.

You might try putting some double stick tape on the back of the ruler so it won't slip as much.

Hesh is on the money - the client's desires rule in most cases.
As for spacing tools, I used to measure with calipers and pencil marks, but after 35 years and zillions of nuts I can do it by eye.
One new SM tool I purchased for starting nut slots is their feather edge file. That thing is sweet! A few strokes is all it takes to place the strings properly before completing the job in a normal fashion.

_________________
"Act your age, not your shoe size" - Prince

Chris, what is the feather edge file? I did a search on their website and can't seem to find something called that. Are you referring to the needle files they sell in sets?

Hey Dan my friend you are not being too much of a perfectionist you are being a Luthier and I suspect a dang good one too!

I do exactly the same thing as you, measure, mark, cut, measure again and find that I wandered off my mark, etc....

It's easy to do since our nut files are wider at times than our marks and our marks get nixed by the file (unless you mark on the nut face and I believe this tip came from David Farmer some months back).

Sounds to me like you are doing fine just a bit frustrated that things can wander and this causes us to want to use the rule many times in the course of making a nut.

What I have been doing lately to reduce my dependency on the thing for other than the initial marking is using my eyes more to differentiate errors in spacing and I am having some luck with it too. I'm pushing 60... and things are starting to fall apart.... but I can still see irregular string spacing so maybe it's not too late.

JF makes a good point with the double stick. I use self stick 120 on my 6" engineer's scale for the same, non-slip reason.

PS: Lots of us struggle with our nuts.... (seriously speaking.... ) and it's been said that it might take 100 nuts before we can get good at it. I've got my time down to an hour.... but Dave C. can make a perfect nut in 20 minutes..... dang show off... Anyway it is something that take time to get comfortable with or at least it has for me....

Dan, I always mark the forward face of the nut w/ the Stu-Mac ruler. It's a small finicky layout for sure but once done, the marks are there to reference as the slots are lowered. when you lift a string out of a slot, it's easy to see any drift in your filing.

Holding the nut face up in a vice helps a lot.

I believe Kevin Ryan is the inventor of the proportional string spacing ruler -- very clever and works great. I have one, but I think my fingers would not notice any difference from conventional equal on center spacing. To get that fraction of an inch additional "between space" I locate my edge spacing .10" on both "E"'s To establish a guide track for the nut files I make the first cut with a fine razor saw. Folks seem to like the results from this strategy.

_________________
Ken Cierp

http://www.kennethmichaelguitars.com/

Frank Ford has a bit about Ryan's proportional ruler on frets.com.
Pat

_________________
formerly known around here as burbank
_________________

http://www.patfosterguitars.com

I also start the cuts with a razor saw - makes the files track much better.

_________________
Steve Smith
"Music is what feelings sound like"

Dan:
No rule here. Stole my method from Don Teeter. Set the 2 e strings to what ever inset you want. Shallow groves to just hold the strings in place. Measure the distance between the 2 e strings. Add up the diameters of the a to b strings and subtract the result from the first measurement. Divide that measurement by 5 and the result will be the distance between strings. Mark and set the a and b strings,shallow groves. Then the same with the d and g strings. Once all 6 strings are set,check each measurement and alter for any minor errors. Then set the strings for height. I must say that I can't detect any difference in spacing while playing(I'm not what is known as a player) but any visual difference looks horrible and to me is a sign of poor work.
Tom

_________________
A person who has never made a mistake has never made anything!!!

My bad. Bought it on eBay from Philadelphia Luthier Tools.
http://www.philadelphialuthiertools.com ... mm-length/

_________________
"Act your age, not your shoe size" - Prince

Ooo that looks like a nice file, and a new website to peruse through that I never found before!

Hesh, thanks for the encouragement, it is appreciated. You give good advice you know that?

Chris, thank you for the tip on the feather edge file, I can definitely make use that in my shop.

Thanks for the tips David on the double sided tape, next job I'm going to give that a shot, I'm sure it'll help quite a bit.

Feather edge files are commonly used to sharpen Japanese-style rip and crosscut pull saws, and are available in a couple different sizes from Woodcraft, Lee Valley, and Highland hardware. We use a #3 file in the shop, which makes a very narrow cut.

http://www.highlandwoodworking.com/japanese3featherfile.aspx

_________________
A constellation only takes shape when one maps the whole.
- Beth Brower

I've used the calculation method described by Tom and the SM string spacing ruler, but what I've used on last several guitars is this template sheet which I like a lot. No calculations needed as long as you like the equal spacing between strings approach, no slipping ruler, and it's infinitely adjustable unlike the string spacing ruler which is incremental (small increments but still incremental).

The back side of the sheet has the layout for a twelve string guitar and a nylon string guitar (with equal distance between string centers)

I'm another of those who starts the slots with a razor saw.

_________________
Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

I use a pointy scribe to mark the lines on the nut when using the SM ruler. Then the razor saw has a groove to start the cut. Never had a problem with slipping.

I usually get the nut perfectly sized to the slot and mark the high and low E so they sit 1/16" inside the bevel of the first fret. Light notch and position the strings.

Then lay the SM ruler over the nut and center it on the strings and mark the rest of the strings and I use a .016 Grobet file to make a notch over the marks. Re-check with the ruler after each notch. You can move the notches a little with the file if needed.

It has worked pretty well. I love the SM ruler.

_________________
It's not what you don't know that hurts you, it's what you do know that's wrong.

I just come in 3mm mark the 1st and 6th, then using the SM ruler, mark spacing with pencil, notch with feather file.
Then start the string slots with the nut files, check with the SM rule.
But I find it can look a little "odd", not sure why, so adjust slightly as I go to make it "look right"
Anyone else find this?

_________________
The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Colin: I may be wrong but it seems to me that the rule could only be right on for a certain set of string sizes. That being said no matter how one gets the strings layed out most likely a bit of tweeking will be needed.
Tom

_________________
A person who has never made a mistake has never made anything!!!

There are 2 schools on thought on string spacing at the nut:

(A) - Every string is centered equidistant from each other.
This will make the wound strings look closer together... and they are because of their diameter.

(B) Equal spacing between the strings.
The wound strings are slightly farther apart from each other compared to the plain strings.

Neither is wrong in my opinion, and I don't believe that many players could tell the diff blindfolded.
Either way - I make nut spacing per client request.
On my own stuff - I go with B.

_________________
"Act your age, not your shoe size" - Prince

At the nut I use equal distance on centers and at the saddle I use equal distance between strings. My reasoning is that your left hand is being placed on the center of the string but your pick is finding the side of the string. In practice, however, I don't think it makes a whole lot of difference.