Search found 32 matches

by gerryt
Wed Sep 18, 2019 3:33 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Complete (almost) guitar - spectrum results
Replies: 3
Views: 4189

Re: Complete (almost) guitar - spectrum results

Thanks for the reply Trevor.

Yep pretty much resigned to the main air being as it is. And re the T(1,1)2 I wouldn't be disappointed to have to reduce the amount of weight to bring it to 180Hz after stringing up.
by gerryt
Wed Sep 18, 2019 3:31 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Complete guitar - frequency testing technique
Replies: 4
Views: 4715

Re: Complete guitar - frequency testing technique

Just watched the preview Trevor. Looks good!
by gerryt
Sun Sep 15, 2019 8:16 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Complete (almost) guitar - spectrum results
Replies: 3
Views: 4189

Re: Complete (almost) guitar - spectrum results

This is the frequency spectrum taken with 100g attached to each side
Freq_100g.jpg
Freq_100g.jpg (59.47 KiB) Viewed 4187 times
by gerryt
Sun Sep 15, 2019 8:02 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Complete (almost) guitar - spectrum results
Replies: 3
Views: 4189

Complete (almost) guitar - spectrum results

As I said in a previous post I'm in the home straight with my first falcate braced guitar. In other previous posts I described frequency test results I got at the closed box stage. The guitar is OM sized and has a side soundport and small-ish arm bevel. The finish is on and buffed and the bridge is ...
by gerryt
Fri Sep 13, 2019 8:20 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Complete guitar - frequency testing technique
Replies: 4
Views: 4715

Re: Complete guitar - frequency testing technique

Brilliant Martin thanks. Getting close with this one. Will post a few pics once complete.
by gerryt
Fri Sep 13, 2019 6:27 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Complete guitar - frequency testing technique
Replies: 4
Views: 4715

Complete guitar - frequency testing technique

Hi all Been a while but I've been building away and I'm almost finished my falcate braced OM. I'm just about to permanently attach the neck (FB extension glued down on a "standard" bolt on neck). I was wondering what the best technique will be to take a frequency spectrum on the completed guitar. Wh...
by gerryt
Tue Apr 16, 2019 9:36 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Just closed the box - strategy?
Replies: 15
Views: 9028

Re: Just closed the box - strategy?

Aye Trevor the sort of fun you have on a rollercoaster! :lol:
by gerryt
Mon Apr 15, 2019 9:48 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Just closed the box - strategy?
Replies: 15
Views: 9028

Re: Just closed the box - strategy?

I'm guessing it's a suck it and see situation!

My next falcate guitars will be using perhaps more suitable woods - Englemann and Oregon Myrtle and Englemann and Apple wood. Might get a bit closer with these. The current build has been a massive learning experience for me - so many new things!
by gerryt
Mon Apr 15, 2019 8:56 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Just closed the box - strategy?
Replies: 15
Views: 9028

Re: Just closed the box - strategy?

Covering the sound port with my hand takes the T(1,1)1 down to 104 Hz so yep a 5Hz difference. I don't think I'll use a sound port again to be honest.

Is the 109Hz a thing to be worried about? Or will the guitar just be less than optimally responsive?

Thanks again.
by gerryt
Mon Apr 15, 2019 7:14 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Just closed the box - strategy?
Replies: 15
Views: 9028

Re: Just closed the box - strategy?

Ok so mass loading the sides has a marked effect on T(1,1)2 and none on T(1,1)1. And adding the bridge has about 0.4Hz of a drop to the T(1,1)2 per gram of bridge for a medium steel string guitar which mine is more or less. The stiffness of the bridge adding a little to the T(1,1)1. What I don't und...
by gerryt
Sun Apr 14, 2019 1:50 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Just closed the box - strategy?
Replies: 15
Views: 9028

Re: Just closed the box - strategy?

https://live.staticflickr.com/7808/46684059065_e6b73d358e_b.jpg So the latest spectrum is after perimeter thinning the top and scalloping the lower ladder back brace. I'm getting T(1,1)1 as 109Hz now. Incidentally out of curiousity I taped a martin stylle ebony belly bridge I had lying around to th...
by gerryt
Sat Apr 13, 2019 5:04 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Just closed the box - strategy?
Replies: 15
Views: 9028

Re: Just closed the box - strategy?

Thanks for that Trevor - much appreciated. I had wanted to bind the fingerboard but I won't be able to if I leave a trimmable fretboard overhang. And I guess the thing with the overhang is to do it so it doesn't look like a mistake! Is there a particular way I could deal with the back? Is it working...
by gerryt
Fri Apr 12, 2019 9:21 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Just closed the box - strategy?
Replies: 15
Views: 9028

Re: Just closed the box - strategy?

https://live.staticflickr.com/7906/40625903853_300fa992e5_c.jpg Ok so I've found and read the instruction for tapping the box and the above is the result. I tried only to touch the sides and not dampen the top or back. The guitar body was on its side on my lap. The two big peaks are at 113Hz and 20...
by gerryt
Fri Apr 12, 2019 9:33 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Just closed the box - strategy?
Replies: 15
Views: 9028

Re: Just closed the box - strategy?

Will do Trevor thanks. It's late here though so tomorrow it'll have to be.

All the best, Gerry
by gerryt
Fri Apr 12, 2019 7:05 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Just closed the box - strategy?
Replies: 15
Views: 9028

Just closed the box - strategy?

Hi all Still working away on my first "the Books" build. I'm at the stage that I've closed the box, trimmed it flush and captured a spectrum as in the image below. https://live.staticflickr.com/7905/33711406638_c2e2af74ca_z.jpg The peaks as I see it (please correct me if I'm wrong) are T(1,1)1 - 112...
by gerryt
Tue Apr 02, 2019 1:17 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Wood for Falcate Braces in UK
Replies: 14
Views: 8425

Re: Wood for Falcate Braces in UK

Just bent my first falcate primaries and secondaries using Sitka from Timberline in the UK and it bent no problem. Thicknessed to 1.7mm and clamped to a form. The triple ply laminate was glued with West Systems epoxy.
by gerryt
Sun Feb 10, 2019 3:56 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Slotted or unslotted
Replies: 2
Views: 2506

Re: Slotted or unslotted

Excellent. Thanks for that Martin. No need for me to change then! I had some carbon fibre rods inlaid into a neck and it was really hard stuff to work (filing a little off the tenon during neck setting).
by gerryt
Sat Feb 09, 2019 9:16 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Slotted or unslotted
Replies: 2
Views: 2506

Slotted or unslotted

In my standard traditional style builds I've always used unslotted bridge pins and slotted the bridge to fit the individual strings. Now that I'm on this journey and trying to apply the Books as fully as I can the question occurs to me what people are doing regarding this matter. I really dislike sl...
by gerryt
Sat Feb 09, 2019 9:08 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Falcate braces - radiusing?
Replies: 7
Views: 4375

Re: Falcate braces - radiusing?

Good to know that it's been done without incident Martin. I'm pretty confident in getting a good join between brace underside and top after sanding in the radius dish but I guess the curved braces could be a complication that I haven't experienced before.
by gerryt
Wed Feb 06, 2019 9:56 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Falcate braces - radiusing?
Replies: 7
Views: 4375

Re: Falcate braces - radiusing?

Thanks (again!) Trevor. It seems slightly counter intuitive to me having been making guitars the 'standard' way for a number of years that just gluing the braces in a radius dish imparts the said radius to the top. That said I'm having to change lots of things about the way I build guitars since get...
by gerryt
Wed Feb 06, 2019 5:35 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Falcate braces - radiusing?
Replies: 7
Views: 4375

Re: Falcate braces - radiusing?

Yep that was exactly what I meant Dave!

Ok so maybe the carbon fibre and epoxy helps with reducing the spring back? I'm thinking there would be no issue even to go ahead and radius the underside of the braces just for a belt and braces approach.....
by gerryt
Wed Feb 06, 2019 12:25 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Falcate braces - radiusing?
Replies: 7
Views: 4375

Falcate braces - radiusing?

Maybe it's the plethora of info in the books or my reading of them but nowhere can I find any mention of putting a radius on the underside of the falcate braces on the top. If there is one can someone give me a page reference please? If there's not am I to assume that the use of epoxy/carbon fibre a...
by gerryt
Mon Jan 14, 2019 10:36 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: My first frequency spectrum
Replies: 9
Views: 5301

Re: My first frequency spectrum

Now you see why I didn't become a mathematician! I added the missing zero and target thickness is now predicted to be 2.71mm. That's a somewhat less scary figure. Actually pretty glad as this top rings like a bell when tapped for the long grain and twisting frequency. In cross grain mode it sustains...
by gerryt
Mon Jan 14, 2019 10:29 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: My first frequency spectrum
Replies: 9
Views: 5301

Re: My first frequency spectrum

Sorry for the stream of posts - I would have edited one of them with more info but I don't seem to be able to. Anyway...spent the evening inputting the rest of the equations to get me to to a target panel thickness and I've had a pretty terrifying result https://farm8.staticflickr.com/7829/458168488...
by gerryt
Mon Jan 14, 2019 9:13 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: My first frequency spectrum
Replies: 9
Views: 5301

Re: My first frequency spectrum

And another quick question if that's ok guys. I'm getting a density figure of 455 for this top and a long grain Young's Modulus of 14.69. Firstly are my figures right and secondly is this top going to be too dense to use in a 14 fret OM style guitar using falcate bracing? I don't have a predicted th...