uery for Trevor re Compensation Calculations

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kiwigeo
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Re: uery for Trevor re Compensation Calculations

Post by kiwigeo » Wed Jun 22, 2016 11:17 am

Trevor Gore wrote:Martin, you're best off ignoring the tension/frequency data on the string packet. D'Addario, (for example) who are one of the few who publish this information, rarely have test results from the string you're using - they extrapolate them from the few tests they have done.
Trevor, your comments supported by results I'm getting for Daddario EJ17 string set I'm currently testing. For the 0.045" A5th string I've just tested I needed to apply 17.8Kg of mass (174.4N force) to bring the string up to correct pitch (110Hz). Scale length I used was 647.7mm (25.5mm). The required tension quoted from the packet is 14.86Kg. Quite a significant difference.
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Re: uery for Trevor re Compensation Calculations

Post by Trevor Gore » Wed Jun 22, 2016 9:59 pm

I needed ~165N to get that string to pitch.

Another thing that string manufacturers do is change the composition of strings but stick with the same labeling. The main culprits for this particular sin were Cleartone, who changed the core diameters of all their wound strings, which significantly affects the stiffness and hence the required compensation. The sound also went from brilliant to crap. Anyone want any excess Cleartone strings? :lol:

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Re: uery for Trevor re Compensation Calculations

Post by kiwigeo » Wed Jun 22, 2016 10:08 pm

18.2Kg to bring the D 4th up to target frequency versus 16.27Kg on the packet.

I've got a 10 pack of EJ17s and the oil patch isn't exactly busy at present so I might just run 5 sets on the rig and see how results vary.
Martin

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Re: uery for Trevor re Compensation Calculations

Post by kiwigeo » Wed Jun 29, 2016 7:41 pm

Currently 3/4 way through testing two sets of Daddario EJ17 strings.....results to be compiled over the weekend and will be available to those who are interested.
Martin

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Re: uery for Trevor re Compensation Calculations

Post by Trevor Gore » Wed Jun 29, 2016 8:57 pm

"Believe me, my young friend, there is nothing - absolutely nothing - half so challenging as simply messing about with strings".

(With apologies to Kenneth Gahame)

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Re: uery for Trevor re Compensation Calculations

Post by kiwigeo » Thu Jun 30, 2016 10:30 am

“It's not courage so much as stubbornness," Alice said frankly. Her lips curled back from her teeth in a grim smile. "I don't like to lose.”
― Django Wexler, The Mad Apprentice
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Re: uery for Trevor re Compensation Calculations

Post by kiwigeo » Sun Jul 03, 2016 12:31 pm

kiwigeo wrote:Currently 3/4 way through testing two sets of Daddario EJ17 strings.....results to be compiled over the weekend and will be available to those who are interested.
Two sets done....have decided to do a third set.
Martin

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Re: uery for Trevor re Compensation Calculations

Post by kiwigeo » Wed Jul 06, 2016 5:50 pm

Still testing...interrupted today by a job interview. First time Ive had a formal interview for a job in 40 years :shock:
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Re: uery for Trevor re Compensation Calculations

Post by Nick » Thu Jul 07, 2016 6:13 am

kiwigeo wrote:Still testing...interrupted today by a job interview. First time Ive had a formal interview for a job in 40 years :shock:
Ahhh, so you decided to apply for that pole dancing job after all then !
"Jesus Loves You."
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Re: uery for Trevor re Compensation Calculations

Post by kiwigeo » Thu Jul 07, 2016 9:35 am

Nick wrote:
kiwigeo wrote:Still testing...interrupted today by a job interview. First time Ive had a formal interview for a job in 40 years :shock:
Ahhh, so you decided to apply for that pole dancing job after all then !
Some of the questions were alot harder to deal with than a dancing pole. Am used to the traditional oilfield "interview" where you sit with the client and consume endless pints of beer and discuss everything except the job.
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Re: uery for Trevor re Compensation Calculations

Post by kiwigeo » Fri Aug 05, 2016 10:07 am

kiwigeo wrote:Richard I rejigged my spreadsheet to present target and fretted string frequencies and it all seems to work.
I take that back.......saddle compensation values are reasonable but adding nut compensation doesnt result in much of a change in fretted frequencies. I think Ive screwed up adding nut compensation in the right place.

Heading off to the special Gore Army substandard recruit re-training facility :cry:
Martin

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Re: uery for Trevor re Compensation Calculations

Post by kiwigeo » Wed Aug 17, 2016 12:10 pm

The spreadsheet is driving me mad...time for a break and then a re-assessment.

Richard I PM and emailed you re your spreadsheet...did you receive the messages?
Martin

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Re: uery for Trevor re Compensation Calculations

Post by Woodsy23 » Wed Aug 17, 2016 1:22 pm

Martin,

Oops. I didn't see that one. I thought I usually got an email notification of a pm.

Anyway, I'm happy to help if I can. I'll look into it tonight.
Richard

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Re: uery for Trevor re Compensation Calculations

Post by kiwigeo » Wed Aug 17, 2016 3:17 pm

Woodsy23 wrote:Martin,

Oops. I didn't see that one. I thought I usually got an email notification of a pm.

Anyway, I'm happy to help if I can. I'll look into it tonight.
Thanks Richard.....as explained in PM/email the way nut compensation is handled in my spreadsheet seems to be not working properly...
Martin

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Reviving an older post

Post by JurgenV » Sat Dec 15, 2018 2:55 am

Hi,

I´m building guitars as a hobby for some years. Actually these guitars have never been really bad but from 11 builds lets say 3 are really good sounding but I never really knew why. When I read about the "BOOK" I organized a copy in a library (actually I could find just one book in whole Germany) "I saw the LIGHT" :) and ordered it from Trevor. Now I´m in the same number frenzy as a lot of others in this forum.
I started with the nut / saddle compensation trying to do it with an excel spreadsheet. In order to have some reference numbers I used the data from "Woodsy23" for his neck model and the input data he posted in his pdf file. With two variables and some boundary conditions I could even use the "solver" from Excel to optimize the errors and recieved a very similar solution as he did with his manual approach. The differences due to me using the formula for theoretical fret positions instead, so basically just rounding errors. So far so good...
Now my questions:
how do I calculate "f" for the first fret? What ever I tried didn´t give me the value Woodsy23 used. Without any compensation the error on fret 1 with this data is -136 cent which i don´t believe :) (see second file)

Question 2 concerns the neck modelling: Ok, I can model the action at each fret according to equation 4.7-22. But how relieable are these models? Are you modelling the neck curve for every new guitar again? Or do you just change the values for relief, nut height and action at fret 12 (or fret 18) and it matches the action for each different model or even for every guitar you build independent of the model?

Hope you can help me out. Thanks in advance

btw if my english sounds sometimes a bit strange.... sorry

Juergen
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