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Hi folks - to measure the scale length on a traditional guitar, I go from the nut to the saddle. In the case of a guitar with a zero fret, how would one measure the scale length? From the zero fret to the saddle? Or still from the nut to the saddle still? Thanks!
RE: Scale length with zero fret (in reply to rombsix)
quote:
ORIGINAL: rombsix
Thanks Rob - wow, this guitar is ULTRA short. It's a 637 mm scale length!
After you measure the distance from zero fret to 12th fret, measure from zero fret to saddle and see is the actual string length is longer that twice times the distance from zero to 12. Make sure you measure to the exact center of the frets.
RE: Scale length with zero fret (in reply to rombsix)
quote:
ORIGINAL: rombsix
Thanks Rob - wow, this guitar is ULTRA short. It's a 637 mm scale length!
Just to clarify...if the measurement from zero to twelfth fret was 637/2 = 318.5mm, then 637mm is the true scale length. The difference between the zero to twelfth and the measure from the twelfth to the saddle (as suggested by estebanana) will show the compensation due to saddle placement. Another method is to just measure the zero fret (from the middle) to where the string leaves the saddle but that's the scale length plus compensation. The use of a zero fret implies there's no compensation at the nut, as one of the reasons for a zero fret is to eliminate the need.
I suspect the 630mm mentioned by Firefrets is a typo? Otherwise, I don't know how that was arrived at based on the information presented.
I would think any increase in compensation due to a reduction in scale length would be inversely proportional to the percentage of the reduction, assuming no reduction in string height above the twelfth is done. There could be a slight increase in compensation at the saddle but nothing dramatic. Maybe I'm missing something here?
RE: Scale length with zero fret (in reply to RobF)
From the middle of the zero fret to the middle of the twelfth fret was indeed 318.5 mm so I multiplied that number by two and got 637 mm. When I measured from the middle of the zero fret to the edge of the saddle (where the string leaves the saddle) closer to the "sound hole" (you'll see why I put that in quotation marks by looking at the video below), I got 637 mm.
RE: Scale length with zero fret (in reply to estebanana)
So just to make sure, based on what I discussed of the measurements I obtained, is this guitar considered a 637 mm scale length instrument? Most guitars I play are 650 mm scale length, but they don't have zero frets, and for those, I measure from the nut to the saddle and I get 650 mm as the value. So for this guitar with the zero fret, is 637 mm (from the zero fret to the saddle) not the scale length? If not, what is it then?
RE: Scale length with zero fret (in reply to rombsix)
It would be a 637mm scale length without compensation. Compensation would make the string length longer by the amount of compensation. The zero fret to twelfth fret is an accurate measure of scale length as it is, by definition, half of the scale length. Scale length is used to determine the placement of the frets. Compensation sits outside of that and that's why the string length doesn't always match the scale length.
So, if anyone asks, tell them it is a 637mm scale length. That the string length and scale length are the same just means this particular instrument is not compensated.
RE: Scale length with zero fret (in reply to rombsix)
quote:
ORIGINAL: rombsix
So just to make sure, based on what I discussed of the measurements I obtained, is this guitar considered a 637 mm scale length instrument? Most guitars I play are 650 mm scale length, but they don't have zero frets, and for those, I measure from the nut to the saddle and I get 650 mm as the value. So for this guitar with the zero fret, is 637 mm (from the zero fret to the saddle) not the scale length? If not, what is it then?
Sorry - I'm just worried I got confused.
650 mm is probably the most commonly found scale over all, it was Torres’ final design version that sort of standardized it, although it’s really a measurement based on inches used in Spain at the time. The metric system did arrive to be standardized in the mad making trades until a bit later.
So that’s why there’s a standard mean of 650mm scale. 650 millimeters is 25.5906 inches. Due to the fast that the metric system is held to a specific length of what a meter is and the old system of what an inch length is, there is a minute amount of ‘historical mensurative slop’ in the conversion between the modern metric system and the old Iberian inch. Which means Torres’ personal ruler was used to create a 25.5 inch scale length, that we now refer to ( in historical error) as ‘the 650’.
Ok so there’s that-
Now any guitar you measure to get a scale length, you’ll want to measure from the stopping point of the string whether that’s a nut front edge or a zero fret center line to the center of the 12th fret and multiply by 2. We’ve established this is ‘Scale’ length. Those stopping points from the guitar headstock side to the center of the 12th fret are universal on any Western fretted instruments, mandolin, guitar, or ukulele etc.
What you also need to consider to get a highly accurate measurement is a meter long steel ruler with Millimeter tick marks. A cloth tape ruler, or a carpenters roller tape could be fallible because it’s hard to hold and the cloth ruler can stretch. You may find if you use a metal meter rule that you get a more accurate measurement that will register a difference between the scale length and the ‘string length’ because it’s difficult to see the 2 mm of compensation added unless you actually lightly clamp the metal ruler to the neck with the Zero end of the ruler butted against the front face of the nut. Then with a magnifying glass or a magnifying visor and a light, check the position of the 12th fret on the ruler.
Then with the ruler still clamped to the neck, check the place on the saddle where the string of making contact with the saddle. Accuracy counts here because it’s easy to miss the 2mm of compensation unless your metal ruler is dead still fixed during both measurements being taken.
Also that guitar is muy chingona, you might get a venereal disease from it. Maybe you should start a course of penicillin just in case.
RE: Scale length with zero fret (in reply to estebanana)
quote:
Also that guitar is muy chingona, you might get a venereal disease from it. Maybe you should start a course of penicillin just in case.
I used the tape measure that my wife employs in her sewing projects, which is my go-to instrument for obtaining accurate dimensions, whatever they may be.
I'll just go with 637 mm scale length and if anyone complains, I'll say that a week's worth of penicillin will resolve any issues they may have.
RE: Scale length with zero fret (in reply to rombsix)
quote:
ORIGINAL: rombsix
quote:
Also that guitar is muy chingona, you might get a venereal disease from it. Maybe you should start a course of penicillin just in case.
I used the tape measure that my wife employs in her sewing projects, which is my go-to instrument for obtaining accurate dimensions, whatever they may be.
I'll just go with 637 mm scale length and if anyone complains, I'll say that a week's worth of penicillin will resolve any issues they may have.
Over the years I’ve noticed you have a recurring ‘cutaway’ habit. I’m no doctor, but I can say there are treatment centers you can go to get help with that situation. Just nod if you need an intervention. We’re all here for you.
RE: Scale length with zero fret (in reply to estebanana)
quote:
ORIGINAL: estebanana
quote:
ORIGINAL: rombsix
quote:
Also that guitar is muy chingona, you might get a venereal disease from it. Maybe you should start a course of penicillin just in case.
I used the tape measure that my wife employs in her sewing projects, which is my go-to instrument for obtaining accurate dimensions, whatever they may be.
I'll just go with 637 mm scale length and if anyone complains, I'll say that a week's worth of penicillin will resolve any issues they may have.
Over the years I’ve noticed you have a recurring ‘cutaway’ habit. I’m no doctor, but I can say there are treatment centers you can go to get help with that situation. Just nod if you need an intervention. We’re all here for you.
And if you are being held hostage by those cutaways, gulpe twice out of compas and we’ll send an away team right away!
_____________________________
I prefer my flamenco guitar spicy, doesn't have to be fast, should have some meat on the bones, can be raw or well done, as long as it doesn't sound like it's turning green on an elevator floor.
RE: Scale length with zero fret (in reply to Firefrets)
quote:
ORIGINAL: Firefrets
quote:
I suspect the 630mm mentioned by Firefrets is a typo? Otherwise, I don't know how that was arrived at based on the information presented.
No, not a typo. It's how I look at scale lengths.
The total distance between nut and saddle is a distance that must include compensation, otherwise the guitar will not intonate well.
So for me, a measurement of 652mm isn't a 652mm scale length. It is a 650mm scale length (plus) 2mm compensation.
A measurement of 637mm is not a 637mm scale length, but a 630mm scale plus 7mm compensation.
If I have a guitar with a 643mm measurement, it is a 640mm scale length, plus 3mm compensation etc.
Obviously the distance from the nut to the middle of the 12th fret can measure what ever it measures, so I'm simplifying things slightly.
Hope that explains my logic.
Are you sure you're not confusing mm with fractions of thousands of an inch or something? 7mm is over a quarter of an inch of compensation, for goodness' sake.
As scale length determines fret placement and the twelfth fret (the octave) is literally half of that then that's the accurate way to measure scale length.* The difference of added compensation at the saddle between a 650 and 637mm scale length would be an increase of a fraction of a mm, almost negligible. Not over three times the average compensation normally found on a 650mm scale instrument. I mean, if we put a capo on the first fret of a 650mm guitar we'll now have an effective scale length that is substantially less than 637mm and the compensation will be unchanged, although it will signify a higher percentage of the new scale length. The guitar will still intonate just fine at the thirteenth and will still play in tune. This is basic Pythagorean stuff.
As an aside, are you pulling my leg or something? I guess in the UK they call it taking the piss? I honestly don't know how you're arriving at those numbers, unless you mean something like 0.07" instead of 7mm, which makes sense, as a mm is about 0.039". Could that be it?
*well, at least when a zero fret is used or as long as there's been no compensation done at the nut. We could also get deep in the weeds and start discussing what rule was used to determine fret placement and if the old "rule of 18" is self-compensating, and on and on, but in no circumstance will we see a 7mm compensation at the saddle. It's just not happening...
RE: Scale length with zero fret (in reply to RobF)
quote:
quote:
ORIGINAL: Firefrets
quote:
I suspect the 630mm mentioned by Firefrets is a typo? Otherwise, I don't know how that was arrived at based on the information presented.
No, not a typo. It's how I look at scale lengths.
The total distance between nut and saddle is a distance that must include compensation, otherwise the guitar will not intonate well.
So for me, a measurement of 652mm isn't a 652mm scale length. It is a 650mm scale length (plus) 2mm compensation.
A measurement of 637mm is not a 637mm scale length, but a 630mm scale plus 7mm compensation.
If I have a guitar with a 643mm measurement, it is a 640mm scale length, plus 3mm compensation etc.
Obviously the distance from the nut to the middle of the 12th fret can measure what ever it measures, so I'm simplifying things slightly.
Hope that explains my logic.
Are you sure you're not confusing mm with fractions of thousands of an inch or something? 7mm is over a quarter of an inch of compensation, for goodness' sake.
As scale length determines fret placement and the twelfth fret (the octave) is literally half of that then that's the accurate way to measure scale length.* The difference of added compensation at the saddle between a 650 and 637mm scale length would be an increase of a fraction of a mm, almost negligible. Not over three times the average compensation normally found on a 650mm scale instrument. I mean, if we put a capo on the first fret of a 650mm guitar we'll now have an effective scale length that is substantially less than 637mm and the compensation will be unchanged, although it will signify a higher percentage of the new scale length. The guitar will still intonate just fine at the thirteenth and will still play in tune. This is basic Pythagorean stuff.
As an aside, are you pulling my leg or something? I guess in the UK they call it taking the piss? I honestly don't know how you're arriving at those numbers, unless you mean something like 0.07" instead of 7mm, which makes sense, as a mm is about 0.039". Could that be it?
*well, at least when a zero fret is used or as long as there's been no compensation done at the nut. We could also get deep in the weeds and start discussing what rule was used to determine fret placement and if the old "rule of 18" is self-compensating, and on and on, but in no circumstance will we see a 7mm compensation at the saddle. It's just not happening...
Sorry, I generalise sometimes, and was on auto pilot with the numbers, hence why I said the following:
quote:
"Obviously the distance from the nut to the middle of the 12th fret can measure what ever it measures, so I'm simplifying things slightly."
I also wrote 'It's how I look at scale lengths'. I didn't realise you guys wanted to talk about real numbers. I've got 637mm on the brain at the moment, as it's the number I've been using when moving a bridge as I write as I'll elaborate on later.
I'll try again....
If somebody tells me they have a 652.5mm scale, in my head I think of that as a 650mm scale, because anything above is added compensation to allow the guitar to intonate.
A 630mm scale is a name we give to guitars that are '630 something' millimetres for easy reference. I don't want to remember their individual lengths exactly, as I'm dealing with lots of guitars.
I can see how you think I'm suggesting 7mm of compensation. In reality many guitars don't measure 615mm at the 12th fret, so the compensation wouldn't be 7mm.
Let me offer some real life examples.
One guitar measures 315mm from the nut to the middle of the 12th fret. This is an 'exact' 630mm scale. However, the distance from the nut to the middle of the saddle on the treble side (not necessarily the intonation point) is 634mm. This is a bit more compensation than you'd expect to find on a 650mm scale as stated earlier.
Another guitar measures around 318mm from the middle of the zero fret, to the middle of the 12th fret. In actual terms you might call this a 636mm scale if being pedantic. I'd still call it a 630mm in terms of simple reference. So if the saddle is set at 637mm it's not 7mm of compensation.
I've just got 637mm on the brain at the moment, as had to move a bridge on an old guitar that had been set too far back, and 637mm is my target intonation point. It's a fret saddle, so I have to get it absolutely bang on, as can't adjust a bone saddle.
I'd still refer to this guitar as a 630mm. It's just habit. You can understand why the number 637 didn't flag in my brain as excessive when simplifying.
RE: Scale length with zero fret (in reply to silddx)
It's actually correct. 315mm is half a 630mm scale. It was that I'd written 330 not 630 after it. You then did the same as me and halved it again ha ha.
RE: Scale length with zero fret (in reply to rombsix)
This is an odd one really, as you can clearly see that somebody has sanded around the bridge at some point, (what a pain) and there's an imprint of the bridge having been moved, but it's a pin bridge.
When I removed the bridge, no holes had been filled, so maybe it started out life with a different type of bridge? Maybe a tie block bridge, or maybe somebody messed up trying to refinish her, but a lot of colour has been lost and I'm not sure I can replace that.
It measured around 20 cents flat, so if you figure that's 20% of 35mm (the size of the first fret box is a semi tone) it was actually out by 7mm.
643mm less 7mm is 637mm .... what a coincidence!
You guys picked the wrong day to be talking to me about 637 scales and 7mm compensations ha ha. No wonder I found it hard to write stuff down lol. My head was already wrecked with this one.
I've had to remove the bridge and fill all the holes since taking this photo. I'm currently deciding if I can get away with gluing a 0.5mm veneer to the underside of the bridge, to give me just a tiny bit more height.
Images are resized automatically to a maximum width of 800px
RE: Scale length with zero fret (in reply to Firefrets)
I don't want to get into any pissing matches but I have to say a couple of things here.
First off, a cent is a unit based on a logarithmic scale. You can't just say 20 cents off in tuning translates to 20% of a 35mm fret interval and then somehow pull 7mm out of your hat. Or I suppose you can. In this day and age people seem to think it's OK to say anything they want. I have no idea because I'm not going down this rabbit hole save to say 7mm compensation is idiotic. So is 4mm. Gimme a break.
I've enjoyed your restoration threads but it's pretty clear to me you aren't a guitar maker and, based on what I've been reading here, I wouldn't trust you with any serious project. Sorry, but you come across way too arrogant for your own good. Seems to be a disease that inflicts people in this business, so indulge me if I'm coming across the same way.
But, enough is enough. I'm pretty near done with this. I don't want to talk anymore. If people can't accept the words of an experienced, trained and qualified luthier without demanding some kind of confirmation bias by vetting their words against the rantings of charlatans then I don't know what to do. I give up.
Ramzi, everything I've told you, not just on this thread but everywhere else, if it's related to guitar making you can take it to the bank. If you don't want to believe me, that's fine too. It's not my problem.
Damn, I'm really pissed off now. I have to be careful with what I say, I just deleted the worst of it. I think I better take a break.
RE: Scale length with zero fret (in reply to RobF)
quote:
I don't want to get into any pissing matches but I have to say a couple of things here.
First off, a cent is a unit based on a logarithmic scale. You can't just say 20 cents off in tuning translates to 20% of a 35mm fret interval and then somehow pull 7mm out of your hat. Or I suppose you can. In this day and age people seem to think it's OK to say anything they want. I have no idea because I'm not going down this rabbit hole save to say 7mm compensation is idiotic. So is 4mm. Gimme a break.
I've enjoyed your restoration threads but it's pretty clear to me you aren't a guitar maker and, based on what I've been reading here, I wouldn't trust you with any serious project. Sorry, but you come across way too arrogant for your own good. Seems to be a disease that inflicts people in this business, so indulge me if I'm coming across the same way.
But, enough is enough. I'm pretty near done with this. I don't want to talk anymore. If people can't accept the words of an experienced, trained and qualified luthier without demanding some kind of confirmation bias by vetting their words against the rantings of charlatans then I don't know what to do. I give up.
Ramzi, everything I've told you, not just on this thread but everywhere else, if it's related to guitar making you can take it to the bank. If you don't want to believe me, that's fine too. It's not my problem.
Damn, I'm really pissed off now. I have to be careful with what I say, I just deleted the worst of it. I think I better take a break.
Why are you being nasty mate? I'm not a guitar maker. I'm a repairer. I've been tinkering with guitars for well over 20 years. I've put the same effort in to learning repair and restoration as you have put in to building.
I'm not arrogant, I'm Autistic, and have trouble expressing myself in written format.
As for the rest, I learnt that from Frank Ford. You're out or order Rob, and unsure where the outburst came from, but hey ho.
Fairly often, I'm asked to correct intonation on an acoustic guitar. I believe this is rightly done at the bridge in the form of a compensated saddle, where each string’s vibrating length can be set to achieve reasonable intonation. There are much more sophisticated methods of achieving intonation correction; there is more than one system of tempering the fretted scale. My interest is in simply achieving the reasonable intonation that's found on a well-made conventional guitar, without undue modification.
At this time, we generally accept modifications at the bridge because bridges are relatively easy to replace. Some systems for correcting intonation require shortening the fingerboard at the nut. This is not currently a generally accepted modification, although it has merit from an engineering standpoint.
I check for intonation by the usual method of playing the string fretted at the 12th fret and comparing to the note produced by playing the harmonic at that same position. Most often, I'm reconfiguring a saddle or bridge to correct for a guitar that plays sharp up the neck. Here's a formula I use to save the effort of trial-and-error.
Let's assume I'm working on a guitar that plays SHARP when fretted, and that all other aspects of set up are satisfactory, e.g. string gauge and action. I’ll start with the Low E, and repeat the procedure for all the strings
Compare intonation at 12th fret using an electronic tuner. Observe the NUMBER OF CENTS sharp the fretted note is compared to the open string harmonic. IT PLAYS 8 CENTS SHARP (that's a lot, but I often see worse.)
ONE CENT IS ONE HUNDREDTH OF A SEMITONE. I think of one cent as ONE PERCENT. And, I think of the number of cents error in intonation as the PERCENT ERROR. So my E strings plays 8 PERCENT SHARP.
Therefore, If I know the LENGTH of a semitone, I can calculate the distance I must move the pivot point of the string to correct for intonation.
My guitar has a scale length of 25-1/4” and I can look up the distance from the nut to the center of the first fret on a fret scale chart, or I can simply measure it. A SIMPLE MEASUREMENT IS ALL I NEED, because I’ll round off the decimal places, so I measure 1.43 inches. (For my purposes, a measurement of 1-1/2 inches is probably accurate enough to get reasonable results, but with my dial caliper I don’t have any trouble getting 2 decimal places.)
Here we go then: FIRST FRET DISTANCE times PERCENT ERROR For my E string, it’s 1.43” x 8% = 0.114” or a little more than 7/64” (a fair distance when you think about it.)
I can now plot my ideal saddle positions for all the strings by starting with the points where the strings cross the saddle. I can choose whether to compensate the existing saddle by carving the top of it fore and aft, or by routing for a wider saddle, or by inlaying the saddle slot and routing to relocate the saddle in the bridge.
The advantage of this method is that it works easily for even the most bizarre instrument, stringing, tuning, and setup combinations.
My biggest source of error in measuring is the intonation measurement with my electronic tuner - you know how the meter wants to move around a bit. . .
Here's a simple explanation of the reasoning, submitted by Greg Neaga of Stuttgart, Germany:
It is easy to think this through if you use a very extreme intonation flaw as an example. Let's assume the pitch at the 12th fret is one complete semitone too flat.
In this case, you would have to move the saddle towards the nut by distance equal to the 1st fret distance.
Assuming the string tension stays the same, this would have the following effects:
1) The open string is raised by one semitone 2) The 12th fret harmonic is raised by one semitone 3) The fretted note at the 12th fret is raised by 2 semitones
Which is exactly what we need in our (admittedly extreme) example.
RE: Scale length with zero fret (in reply to Firefrets)
I don't have to study. I know my sh*t. But I'm always open to learning. I don't consider myself to be anything but what I am. I don't know why people in this business think they're so special, there's thousands of us and most do really good work. I'm just asking for clarity.
Thanks for explaining your communication difficulties. It makes a difference and I apologize if I was harsh. But I don't apologize for demanding clarity in the Lutherie section. It's up to you to learn from guys like me, to be honest, at least when it comes to that. As far as restoration work goes, I've already told you I've enjoyed your posts. I see restoration, guitar making, and repair as three distinct disciplines and I don't claim to have expertise in restoration. But I'm going to suggest you consider your words because some of the stuff you're posting is simply incorrect.
Any rate, I don't hold grudges. I'm upset with myself more than anything for the way I spoke but I'm not yet ready to take back my words.
*edit* OK, I see you've modified your reply to remove the 'go study' remark. I appreciate that.
Look, there's room here for everyone and I'm not in the business of making enemies. I'm Canadian and I think we're all walking around with an undercurrent of low level rage these days due to the unrelenting existential threats we've been facing from south of our border. I'll try to do better. Just show a bit of respect. I really do know my stuff, and I don't really like tooting my own horn. I'd rather just excuse myself from the proceedings before it comes to that. It's not how I want to live my life.
RE: Scale length with zero fret (in reply to Firefrets)
If that's a true 630mm scale length and the action isn't through the roof then it's highly unlikely that that guitar is playing in tune. But, if it is, I'd have to examine it myself to fully explain why. There may be more going on here than what meets the eye at first glance. For instance, the fret crowning itself can have an impact. So can the fret placement and how the slots were cut. I have an old Contreras flamenco guitar here that by all accounts shouldn't play in tune but it does, kinda, after a fashion, solely because someone put ultra jumbo frets on it and filed them so they'd contact the string at the front. A mess and an affront to any serious luthier. I need to replace the fingerboard on that one. Eventually, if I ever get around to it...
I can trot out many examples. For instance, some Russian guy sent me a "vintage Telecaster" to restore. Well, the body might have been a vintage short scale fender of some variety and it was a tele's neck of indeterminate age. The neck was filed to fit the pocket and the pocket was also adjusted. Probably with a broken beer bottle. The neck pointed south. Neck didn't match the body's scale length so they pulled the bridge and arbitrarily put it down somewhere. About 2.5 inches off, to be exact, and pointing north. To make the bridge fit they had hacked away at the body with a Forstner bit. They had intonated it to the 11th fret and complained it had tuning issues. They asked me to debug the pickups. I plugged it in and it almost blew my amp across the room. Needless to say, I didn't take the job.
At any rate, I don't want to discourage you from posting or from feeling proud of your work. I'd rather leave the Foro than do that to somebody, so if it's an issue with you please stay. If I've made you feel uncomfortable or unwelcome then that tells me maybe it's time for me to withdraw from the place. I'm OK with that. It's been a good run.
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