Top Plate Thicknessing
Top Plate Thicknessing
Hi Guys-I recently purchased the Gore & Gillet 2 volume book set and am very pleased with the content. I am however struggling to understand the equations used to establish the top plate thickness (4.5.2-3 Vol 1). Can you please give me an example of actual measurements used and the steps to take?. I understand that I need the frequencies for long, cross, and twist which I can do no problem, but beyond that I don't understand what else I need or how to use the equations. Can you help please? Paul from Auckland New Zealand
Re: Top Plate Thicknessing
Inputs are the three frequencies, dimensions and weight of the plate. You can work the formulas manually or code them into a spreadsheet. problems can be encountered with units and some of the spreadsheet coding. There are a few threads that cover these issues.Dolds wrote:Hi Guys-I recently purchased the Gore & Gillet 2 volume book set and am very pleased with the content. I am however struggling to understand the equations used to establish the top plate thickness (4.5.2-3 Vol 1). Can you please give me an example of actual measurements used and the steps to take?. I understand that I need the frequencies for long, cross, and twist which I can do no problem, but beyond that I don't understand what else I need or how to use the equations. Can you help please? Paul from Auckland New Zealand
Martin
- Trevor Gore
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Re: Top Plate Thicknessing
I'm not sure I can explain it any differently to what's in the books. All the nomenclature is explained on Design p. 4-58 and the equations are on page 4-59 et.seq.. Basically, just fill in the numbers and evaluate the equations.
There's some discussion about Equ. 4.5-5 here, but if you have the second edition those things are fixed and you should ultimately end up with the numbers in Table 4.5-3.
Excel can give some spurious answers even when there are no coding errors, so if your numbers don't match, check for errors and if there are none, try coding it differently and see if that fixes things.
There's some discussion about Equ. 4.5-5 here, but if you have the second edition those things are fixed and you should ultimately end up with the numbers in Table 4.5-3.
Excel can give some spurious answers even when there are no coding errors, so if your numbers don't match, check for errors and if there are none, try coding it differently and see if that fixes things.
Fine classical and steel string guitars
Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.
Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.
Re: Top Plate Thicknessing
Thanks Trevor, the thread has helped. Does anyone have a spreadsheet they could share that I could use? Cheers
Re: Top Plate Thicknessing
I could flick you a spreadsheet but I wouldn't be comfortable doing so without a nod of approval from Trevor. Trevor's books were written as a guide rather than a step by step build by numbers affair...ie the primary intention is to get you to understand the theory and then incorporate same in your own calculations/spreadsheets etc. Coding up a spreadsheet is actually the best way to really understand the theory as well as getting you familiar with spreadsheet skills that you'll find useful if you decide to get into the modeling or working out nut and saddle compensation.Dolds wrote:Thanks Trevor, the thread has helped. Does anyone have a spreadsheet they could share that I could use? Cheers
Have a go at doing up a spreadsheet and if you hit a dead end we can re-visit your request

Martin
- Trevor Gore
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Re: Top Plate Thicknessing
Exactly.kiwigeo wrote:Coding up a spreadsheet is actually the best way to really understand the theory as well as getting you familiar with spreadsheet skills that you'll find useful if you decide to get into the modeling or working out nut and saddle compensation.
I'm happy to help people out with their spreadsheets, but you need to have a good go at it before you send it to me.
Fine classical and steel string guitars
Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.
Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.
Re: Top Plate Thicknessing
Thanks Guys-I will give it a go, and take up your offer if need be. Cheers
Re: Top Plate Thicknessing
Hi Trevor-I have now made a spreadsheet and used some of the suggestions in this forum, and the calculations come out, but I have a few Questions about my spreadsheet-can I send the spreadsheet via pm to you please? cheers Paul
- Trevor Gore
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Re: Top Plate Thicknessing
Well done in getting it all to work out.
Happy to answer questions on the forum, if its OK by you (then everyone learns). If I really need to see your sheet, best to contact me via my direct email.
Happy to answer questions on the forum, if its OK by you (then everyone learns). If I really need to see your sheet, best to contact me via my direct email.
Fine classical and steel string guitars
Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.
Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.
Re: Top Plate Thicknessing
Hi Guys-I have now completed a spreadsheet as per Trevor's book which works, (I think), but I have a few questions:
1)How do we calculate the average body size?. I used 1.256410256, as I saw this entered into a formula posted by Oliver @ jaggitone
2) Do we need to use the E long/E Cross calculation in anyway as I saw this in the table at 4.5-3
3) I used 0.94146 to start the formula off to get the top plate thickness (once again because Oliver @ jaggitone posted this), but referring to Equ. 4.5-7 the number used is 0.95977. Which one is correct and why?
4) In respect to the panel mass reference at Table 4.5-3 (last column on the right), is this the panel mass of the final thicknessed top?
Thanks again for any help.Cheers Paul
1)How do we calculate the average body size?. I used 1.256410256, as I saw this entered into a formula posted by Oliver @ jaggitone
2) Do we need to use the E long/E Cross calculation in anyway as I saw this in the table at 4.5-3
3) I used 0.94146 to start the formula off to get the top plate thickness (once again because Oliver @ jaggitone posted this), but referring to Equ. 4.5-7 the number used is 0.95977. Which one is correct and why?
4) In respect to the panel mass reference at Table 4.5-3 (last column on the right), is this the panel mass of the final thicknessed top?
Thanks again for any help.Cheers Paul
- Trevor Gore
- Blackwood
- Posts: 1638
- Joined: Mon Jun 20, 2011 8:11 pm
Re: Top Plate Thicknessing
A few answers:Dolds wrote:Hi Guys-I have now completed a spreadsheet as per Trevor's book which works, (I think), but I have a few questions:...
1) I don't use a term "average body size"
2) No
3) See this
4) Yes (but you need to use the area of the top for the guitar you're building, typically around 0.14m^2)
Fine classical and steel string guitars
Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.
Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.
Re: Top Plate Thicknessing
Thanks Trevor-so what is the calculation for the 'average body size' better termed as and how do I calculate it?. The spreadsheet I sent you references this as cell D9? cheers
- Trevor Gore
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- Posts: 1638
- Joined: Mon Jun 20, 2011 8:11 pm
Re: Top Plate Thicknessing
I've no idea.Dolds wrote:Thanks Trevor-so what is the calculation for the 'average body size' better termed as and how do I calculate it?.
So I take it you didn't write the spreadsheet?Dolds wrote:The spreadsheet I sent you references this as cell D9?
Fine classical and steel string guitars
Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.
Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.
Re: Top Plate Thicknessing
yes I wrote the spreadsheet
Re: Top Plate Thicknessing
I have sorted it now, so all good.Thanks for your help guys
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