compensation

[DarwinStrings]

G'day Trevor, I was wondering, to save me a bit of work if I could use your nut/saddle compensation figures from Table 21-2 if I have a scale length that is slightly longer than the 645.16 you used. The scale I am using is 647.7 and will use the same strings you have quoted.

Jim

[DarwinStrings]

What I am really asking here is if I use your figures for the longer scale will I still get the tuning a little better than the Quick and dirty method as that is what I had planned to use.

Jim

[charangohabsburg]

Hi Jim, not Trevor here (obviously ) but, 1) how much compensation-difference would you expect by just roughly estimating it without the use of any mathematical formula, 2) how would you measure that, 3) how would you make the nut and saddle to the precision these differences would require, 4) are your frets normally placed with a comparable precision to that one and finally, 5) are there some variable factors in the finished instrument (type of string, finger pressure, just to mention two) that are much greater than such a compensation difference for a scale length difference of 2.5 millimetres? Well, again, this is just my take on it.

Cheers,

[jeffhigh]

Since Trevor appears to be MIA, the answer is yes, Jim
I have done exactly that.

[DarwinStrings]

Hi not Trevor.

1) how much compensation-difference would you expect by just roughly estimating it without the use of any mathematical formula,

I don't know but would expect a improvement.

2) how would you measure that,

AP Tuner 3.07

3) how would you make the nut and saddle to the precision these differences would require,

Laser eyes.

4) are your frets normally placed with a comparable precision to that one and finally,

My frets are as good as Stewy Macs templates and the set up I use.

5) are there some variable factors in the finished instrument (type of string, finger pressure, just to mention two) that are much greater than such a compensation difference for a scale length difference of 2.5 millimetres?

So you are saying "Go for it Jim, she'll be right mate"? Which is probably what I would do if there was nobody to ask first, then check it with a tuner and if it looks bad then go for the quick and dirty method with a new nut and saddle which suits me.

Jim

[DarwinStrings]

Thanks Jeff, Cool, as I made a template for a pin rout yesterday to suit. I say Trevor first cause this is his coffee shop.

Jim

[kiwigeo]

Trevor has been consumed by a giant rogue mathematic equation

[charangohabsburg]

[...]

1) how much compensation-difference would you expect by just roughly estimating it without the use of any mathematical formula,

[...]

2) how would you measure that,

AP Tuner 3.07

Well, I meant to say how do you measure the dimensional difference.

4) are your frets normally placed with a comparable precision to that one and finally,

My frets are as good as Stewy Macs templates and the set up I use.

In this case, my guess is that the difference in compensation of a 645.16 mm scale compared to the one of a 647.7mm scale is smaller than the play in the fret slotting jig in order the saw would not bind.

So you are saying "Go for it Jim, she'll be right mate"? Which is probably what I would do if there was nobody to ask first, then check it with a tuner and if it looks bad then go for the quick and dirty method with a new nut and saddle which suits me.

Yes, that's what I am saying more or less. I think recalculating compensation would me of a merely academic interest.

As you know I have only built very few instruments so far, but I also have a few dozens of repairs under my belt, and many of them had to do in one or the other way with intonation (bridge issues, fretboard issues, string action issues...), and these instruments had scale lengths of between 250mm to 670mm. I have made all of them intonate decently, and the interesting part is that the short scaled dwarfs needed about the same amount of compensation as the largest guitar, and always had to do more with the string type and action than with the scale. These were all nylon strung instruments though, and steel strings certainly are more critical, but still... I just would go for it with the same compensation. Going again through the maths maybe would give you more confidence though (never believe your ears! ...just kidding).

Cheers,

[DarwinStrings]

You did not address number 3 Markus so I am assuming you don't believe I have laser eyes

I am now a little confused as table 4.7-3 in the black book gives different values to table 21-2 in the white book, both for steel with 645.16 scale and the same string. I must be missing something but not sure which one I should use now.

Jim

[Trevor Gore]

Trevor has been consumed by a giant rogue mathematic equation

Well, the guys at the Modal Tuning Course at Gerard's country mansion were probably hoping...

Since Trevor appears to be MIA, the answer is yes, Jim
I have done exactly that.

What Jeff said. You could scale the off-sets by the ratio of the scale lengths, but seeing as the ratio of the scale lengths is generally less than ~2%, it's not worth bothering with.

I am now a little confused as table 4.7-3 in the black book gives different values to table 21-2 in the white book, both for steel with 645.16 scale and the same string. I must be missing something but not sure which one I should use now.

Use the figures in the white book. Both are right, because both are for a set-up in the "typical" range. I think the difference was the amount of neck relief I allowed and as you can see, the optimised answer is quite dependant on the amount of neck relief you have. The white book has the full set-up specified, whereas the black book hasn't. Of course, if I'd been a bit sharper at the time, I'd have used the same numbers!

[DarwinStrings]

Oh Good and thanks again for your time Trevor. I used the figures in the white book for my template and was thinking the black book was maybe a different relief or action as it did not mention those things in the table.

Jim

[charangohabsburg]

You did not address number 3 Markus so I am assuming you don't believe I have laser eyes

Oh no, I don't not believe. But as it doesn't matter I just didn't care.
I really do not see a reason why I should not believe that when you obviously have a bolt on neck you could not have laser eyes.

[jeffhigh]

Here/s a commercially available compensated nut
Unfortunately it does not move the contact points towards the first fret but away on the e, b and g
Must make it worse, but none of the buyers seem to complain.
http://www.ebay.com.au/itm/AxeMasters-C ... 51a2fa7327

[Trevor Gore]

HELP!!!! I'm drowning in snake oil!

17 sold and twelve positive comments as feedback: 2 Awesomes, 2 5 stars and 5 A++++ etc.. It's not even original snake oil.

There's this mob of course, who have now upped their BS so that strings on their modified guitars operate in compression.

But there's only the one real thing. It comes not for $40, not for $22 but for FREE on all Gore guitars.

Unfortunately (for the opposition), it works.

[Nick]

HELP!!!! I'm drowning in snake oil!

17 sold and twelve positive comments as feedback: 2 Awesomes, 2 5 stars and 5 A++++ etc.. It's not even original snake oil.

There's this mob of course, who have now upped their BS so that strings on their modified guitars operate in compression.

But there's only the one real thing. It comes not for $40, not for $22 but for FREE on all Gore guitars.

Unfortunately (for the opposition), it works.

Obviously got to up the BS factor Trevor
Joe public obviously takes more notice of pseudo science than cold hard facts.

[jeffhigh]

Apparently Ernie Ball have it patented

http://www.google.com/patents/about?id= ... string+nut

and won a court case against earvana

Seems ludicrous when luthiers have been doing this sort of thing to fix tuning problems for years

[Trevor Gore]

There are literally dozens of patents relating to nut intonation, very few grounded in any sort of science. Like Jeff, it beats me how ANY of these patents got granted. I suppose that's what lawyers get paid for.

Tommy Thompson wrote a piece on the "Enharmonic Guitar" in 1829. Both Louis Panormo and Fanc Lacote "borrowed" the ideas and built guitars with adjustable fret positions for each string, and included adjustability at the nut, too, for good measure. Louis was quickest off the mark, building his first prototype in 1829, whilst Franc followed ~1850. Both were searching for a just intonation solution in multiple keys on the one guitar.

I'm not as ambitious. I'm just trying to get a guitar to play equal temperament properly, which is a pretty rare thing, anyway.

[DarwinStrings]

Thanks for the tip Jeff, might have to get a few. Do they come in hollow plastic?

Jim

[jeffhigh]

I can do that for you Jim
Exclusive compensated polymer nuts with resonance chambers (PAF)

[DarwinStrings]

I had a bit of a look at those patents Jeff and it got me thinking. If I spend my life savings on a Lawyer (instead of helping out that Nigerian Prince I have been chatting to online) I reckon I will be able to patent guitars. Don't any of you blokes worry though cause I will send you all my bank details so it will be easy for you to pay royalties every time you sell one, Martin and Gibson etc, I will just bill monthly. Once I get back my savings with a reasonable amount of interest on top I will buy you all a box of Earvana's ones so you don't have to bother shaping your own.

Jim