Search found 731 matches

by seeaxe
Thu Aug 19, 2021 5:19 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Collecting 4DOF models
Replies: 26
Views: 42318

Re: Collecting 4DOF models

So if I mold the cylinder shape with axis parallel to the grain (i.e. sides of the top fall away from the center under the strings), then that increases cross-grain stiffness, I think. So when I apply the downward-only force of the strings as in an archtop, it acts like a compression arch bridge. A...
by seeaxe
Wed Aug 18, 2021 7:50 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Collecting 4DOF models
Replies: 26
Views: 42318

Re: Collecting 4DOF models

Hi Greg How have you incorporated the curve in the top into your calculation of I? I cant see it in the spreadsheet. Apparently the formula for the I of a curved shell is in the later editions of Roark and Young. I gave mine away when I retired a few years ago. A 10mm rise will make a big difference...
by seeaxe
Wed Aug 18, 2021 7:10 pm
Forum: The Gallery
Topic: 16" Archtop
Replies: 11
Views: 9603

Re: 16" Archtop

Lovely. Love the wood combinations and the binding looks great. Does the soundport make much difference with an archtop??
by seeaxe
Sun Aug 15, 2021 12:43 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Collecting 4DOF models
Replies: 26
Views: 42318

Re: Collecting 4DOF models

Will be interesting. How are you going to calculate your I value for a curve/recurve archtop with the normal two strut braces?? Does the fact that the "soundhole" is two F holes make a difference? Given that the top is significantly arched, its going to act more as a shell than a beam. Beams can be ...
by seeaxe
Sat Aug 14, 2021 12:31 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Calculating soundboard rigidity and brace stress
Replies: 6
Views: 13506

Re: Calculating soundboard rigidity and brace stress

Watch out for shear stresses as well as bending stress. I recall something in the books about balsa failing in shear well before the flexural limit was reached.
by seeaxe
Sat Aug 14, 2021 12:28 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Soundport and Weight Effects on Frequencies
Replies: 6
Views: 12881

Re: Soundport and Weight Effects on Frequencies

Thanks Dave, not good to hear but at least some common ground. Have you checked its monopole mobility? Might pay to do that before you pull it apart. For my one, Ive since blocked off the old sound port, routed new almost elliptical (dont ask, i dont want to talk about it :| )sound port on the other...
by seeaxe
Sun Aug 08, 2021 9:42 am
Forum: Instrument Builders Forum
Topic: Torrefied Tonewood
Replies: 24
Views: 27226

Re: Torrefied Tonewood

I don't really think it is going to make a guitar sound more like a Torres! D I dunno mate. I think Ive discovered the secret to making an instrument that sounds like a Torres. Presenting my new Antonio de Torres moustache kit. Wear this moustache while youre building and I guarantee your instrumen...
by seeaxe
Sat Aug 07, 2021 9:16 am
Forum: Instrument Builders Forum
Topic: Falcate - without CF or epoxy
Replies: 2
Views: 3427

Re: Falcate - without CF or epoxy

The reasons it is there are all in the book.
by seeaxe
Wed Aug 04, 2021 8:50 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Calculating soundboard rigidity and brace stress
Replies: 6
Views: 13506

Re: Calculating soundboard rigidity and brace stress

Here you go. I cannot see your spreadsheet but I amended my own to match the figure and got the same results as in Tab 4.4-2. Perhaps check your understanding of the parallel axis theorem? If you want me to send me your email in a pm Ill happily send this to you, with the usual caution about using o...
by seeaxe
Mon Aug 02, 2021 6:48 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Soundport and Weight Effects on Frequencies
Replies: 6
Views: 12881

Re: Soundport and Weight Effects on Frequencies

Hi Martin Its strung the right way (lefty) but i put the soundport in for when i lent it to my guitar teacher, so thats on the wrong ( righty) side. Ill block it off and tear it a new one on the other side. I need to come up with a clever way of blocking off the soundport so that it can be opened up...
by seeaxe
Mon Aug 02, 2021 5:45 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Soundport and Weight Effects on Frequencies
Replies: 6
Views: 12881

Re: Soundport and Weight Effects on Frequencies

Good point about brightness John. Not sure if there's an objective way of measuring that. I had thought that was a function of some of the higher frequency resonances, havent looked in detail at those yet but there does seem to be a decent number of clear peaks further up the graph. The old guitar "...
by seeaxe
Sun Aug 01, 2021 5:51 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Collecting 4DOF models
Replies: 26
Views: 42318

Re: Collecting 4DOF models

Out of interest i weighed the various bits this morning. My soundboard weighs 196g. There's some to trim off round the edges but id expect that to not be more than 10 grams. Its Lutz with a thickness is 2.3mm, 10mm high by 5mm wide tapered braces. Does anyone else weigh theirs and if so what sort o...
by seeaxe
Sun Aug 01, 2021 5:09 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Soundport and Weight Effects on Frequencies
Replies: 6
Views: 12881

Soundport and Weight Effects on Frequencies

This post relates to my first falcate braced guitar, which i have posted about elsewhere. Having finally sorted out the tapping/VA stuff I decided to go back and reanalyse the guitar. I had prepared 4 steel weights and bolted them all in to see what difference it made to the sound. Not a huge amount...
by seeaxe
Sun Jul 25, 2021 6:06 pm
Forum: Instrument Builders Forum
Topic: My third guitar
Replies: 9
Views: 7428

Re: My third guitar

Stunning! You would have to be pleased with that.
What kind of bracing did you use? Looks like it might be a falcate!!
by seeaxe
Sun Jul 25, 2021 11:10 am
Forum: Instrument Builders Forum
Topic: Beginners question
Replies: 6
Views: 6107

Re: Beginners question

I like to notch in my Xbrace and upper transverse brace into my kerfing. The main benefit for me is that it makes lining up the plates a doddle when I have to glue the sides to the top. Some well respected luthiers believe that this is essential if the braces are to act efficiently on the soundboar...
by seeaxe
Fri Jul 23, 2021 7:10 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Trevor’s video by Robbie
Replies: 14
Views: 24994

Re: Trevor’s video by Robbie

Will add my appreciation here too. There's a few vital VA set up steps that aren't mentioned in edition 1 of the books. The mic set up stuff is helpful too, especially as its explained for two different versions of windows. I must admit I dithered a bit over the cost - but put in perspective its abo...
by seeaxe
Fri Jul 23, 2021 8:33 am
Forum: Instrument Builders Forum
Topic: Classical Build (s) - Hopefully falcate!
Replies: 96
Views: 106088

Re: Classical Build (s) - Hopefully falcate!

Update. I added some side weights and tap tested as i went. I got the main top resonance to 190 fairly easily. It sounds a bit brighter which is good but i still have a few muddy notes. Unless im imagining things the F#4 dies about twice as quickly as everything else. Doesnt seem to affect F#3. This...
by seeaxe
Tue Jul 20, 2021 8:33 pm
Forum: Instrument Builders Forum
Topic: Classical Build (s) - Hopefully falcate!
Replies: 96
Views: 106088

Re: Classical Build (s) - Hopefully falcate!

I thought I was done with this but I'm not. I noted that the bridge rotation was much lower than expected and over time I have become a bit unhappy with the sound. It doesnt sound as bright and responsive as my previous guitar, built following Cumpiano and Natelson. But as Trevor points out, I shoul...
by seeaxe
Tue Jul 13, 2021 5:54 pm
Forum: The Gallery
Topic: New OM
Replies: 4
Views: 7074

Re: New OM

That looks lovely Peter, elegant and refined. I bet it sounds as good as it looks.
by seeaxe
Tue Jul 13, 2021 5:51 pm
Forum: Instrument Builders Forum
Topic: New member introduction
Replies: 8
Views: 10557

Re: New member introduction

Welcome from across the ditch!! (the ditch to the east, not the ditch to the south, that is) Have been down a similar road to you, but coming from a guitar background, started taking classical lessons after I started building guitars and soon realised I needed to build my self one, that was 10 years...
by seeaxe
Tue Jun 29, 2021 7:28 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: How useful is the CF under the brace?
Replies: 15
Views: 30510

Re: How useful is the CF under the brace?

I havent built any falcate steel strings but if i did, I would put the tow under the bridge plate not over it. What Trevor pointed out if I understood him correctly is that while the tow on the sound board is very close to the neutral axis at first, the effect of long term creep will move ghe N.A. f...
by seeaxe
Tue Jun 29, 2021 7:08 pm
Forum: Instrument Builders Forum
Topic: What happens when you die?
Replies: 11
Views: 9795

Re: What happens when you die?

Well if you get enough warning you can use the spare wood stash to knock up a coffin. Just make sure you get big enough falcate braces under the lid :mrgreen: I've got two sons, im sure they will sort it out one way or another. I dont have that much wood anyway. Going to do my best to use it all up ...
by seeaxe
Tue May 25, 2021 7:13 pm
Forum: Instrument Builders Forum
Topic: Tail wedge
Replies: 10
Views: 7632

Re: Tail wedge

Sounds lovely, Nigel, just like your Geordie accent, which will be in my head from now on whenever I read your posts. :D
I wandered off into a number of other of your videos, didn't realise you ran a luthier blog too, you have probably mentioned it but if so I missed that.

Like the tail wedge too.
by seeaxe
Mon Apr 26, 2021 1:34 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Bolt On Neck truss Rod
Replies: 3
Views: 5719

Re: Bolt On Neck truss Rod

I have put tape over the truss rod slot before, its quick and easy but these days I glue a thin strip of wood in so I can flatten the neck before fitting the fretboard. If you want to be able to adjust the truss rod while the neck is bolted on, have a think about how you will get past the upper tran...
by seeaxe
Sun Apr 25, 2021 7:41 pm
Forum: The Gallery
Topic: Rain Drop Figure Koa Teor Uke
Replies: 6
Views: 8098

Re: Rain Drop Figure Koa Teor Uke

Thanks for that, Allen

That sounds as beautiful as it looks. Selling ukes to Hawaii.....impressive, but not surprising.