Search found 1330 matches

by Trevor Gore
Sat Aug 18, 2018 1:08 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Rosette Router Jig
Replies: 1
Views: 70

Rosette Router Jig

Below, as per a request , a few photos of my precision router jig as used for rosettes. A few things go together to make this thing accurate. First, the large diameter pivot (10mm), the stiff structure of the thing, low runout after-market router collets on the DeWalt trimmer and the anti-backlash a...
by Trevor Gore
Sat Aug 18, 2018 12:25 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: NEW BUILD tap testing Englemann
Replies: 5
Views: 206

Re: NEW BUILD tap testing Englemann

The trip was very good, thanks. Was over with Robbie O'Brien doing the Modal Tuning Course a couple of times. Nice burst on that Gilet guitar! Just looking at the frequency responses can you tell if a particular piece is stiff across the grain, ie high Fc equals stiff piece of timber across the grai...
by Trevor Gore
Thu Aug 16, 2018 11:44 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: NEW BUILD tap testing Englemann
Replies: 5
Views: 206

Re: NEW BUILD tap testing Englemann

Any comment would be appreciated, some time since I did the course and had used the formula. Lower bout at 380mm is large for a 00 sized guitar. They are usually around classical size at 360-370mm. I recently measured one of Gerard's 00's at 370mm. I think CF Martin make them a little smaller than ...
by Trevor Gore
Thu Aug 16, 2018 11:36 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Carbon Fibre Thickness for Bridge
Replies: 1
Views: 41

Re: Carbon Fibre Thickness for Bridge

I am making a contemporary classical walnut bridge. I intend to use 2 layers of carbon fibre cloth which is .5mm thick - is this OK or does the cloth need to be thicker to give the correct amount of stiffness? The CF cloth as spec'd in the book (198gm/m2) measures up at ~0.27mm thick. Works fine. A...
by Trevor Gore
Thu Aug 16, 2018 11:18 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: First Falcate underway! Plate Thickness question?
Replies: 4
Views: 76

Re: First Falcate underway! Plate Thickness question?

For the Top plate, Trevor lists an f value of 75 to plug into the thickness calculation, but doesn't specify the bracing. For my bear claw sitka top, I get 3mm with an f value of 75, 2.8mm for 70, and 2.6 for 65. Should I use a lower value for falcate bracing? I use 75 with falcate bracing as per t...
by Trevor Gore
Wed Aug 15, 2018 7:21 pm
Forum: Instrument Builders Forum
Topic: J45 headstock design
Replies: 12
Views: 351

Re: J45 headstock design

Francis wrote:
Tue Aug 14, 2018 4:12 am
Not sure about the black 510's, I think the Cosmo version may suit better?
That's a great deco heastock. Shurely (!) it needs the Grover style deco tuners to match...(Other brands are available!!)

Image
by Trevor Gore
Tue Aug 07, 2018 1:11 am
Forum: The Gallery
Topic: Odd Ball Junior
Replies: 4
Views: 179

Re: Odd Ball Junior

Nigel, I hope that park bench isn't home these days.... :D

Nice job, BTW!
by Trevor Gore
Tue Aug 07, 2018 1:01 am
Forum: Instrument Builders Forum
Topic: Hard shellac touch ups - pale areas
Replies: 7
Views: 303

Re: Hard shellac touch ups - pale areas

If you sanded through to the wood, and took some "sun tan" out of the wood, the "sun tan" seems to take for ever to catch up, if it ever does. If you just sanded shellac, because all shellac has some tint to it, you have to match the thickness of coating pretty exactly in order to build to the same ...
by Trevor Gore
Thu Aug 02, 2018 1:10 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Further J45 questions
Replies: 12
Views: 606

Re: Further J45 questions

... I have golden shellac flakes but I've used bullseye (I think) shellac on a harp in the past. Is that a better bet for preventing tear out as it won’t colour the spruce?... I use either blonde or Platina, as those are the only two types of shellac I use. Neither of those colours the wood, but I ...
by Trevor Gore
Wed Aug 01, 2018 11:48 am
Forum: Instrument Builders Forum
Topic: Gidgee
Replies: 11
Views: 435

Re: Gidgee

Anyone used Gidgee for back and sides? For guitars, yes, a couple of times. Here's one. The other one looked much the same, but I left out the sap wood. Hard to bend the figured wood without leaving flats in it and very dense at ~1300kg/m^3. The straight grained wood planes fine, but the figured wo...
by Trevor Gore
Sun Jul 29, 2018 8:39 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Further J45 questions
Replies: 12
Views: 606

Re: Further J45 questions

One thing puzzles me though. The book indicates routing the binding then the purfling. If you use a ball bearing to dictate the depth and you do it that way around what does the bearing reference when cutting the purfling? I'm using the LMII router cutter rather than the Stewmac one. Originally, on...
by Trevor Gore
Fri Jul 20, 2018 5:46 pm
Forum: The Gallery
Topic: Indigenous themed retro SS and classical
Replies: 8
Views: 441

Re: Indigenous themed retro SS and classical

Thanks, all, for the kind words. What did you use for the inner ring material? It's palm. It came from the guy next door who had to take some trees down. Sorry, I don't know exactly what type of palm. I think all the trees that came down were the same, but there are lots of different colours availab...
by Trevor Gore
Thu Jul 19, 2018 11:40 pm
Forum: The Gallery
Topic: Indigenous themed retro SS and classical
Replies: 8
Views: 441

Indigenous themed retro SS and classical

I've not posted one for a while, so here's two! Both in blackwood and Lutz, both slot heads, both with an indigenous themed rosette. I tried Schallers on the SS after a twenty year holiday from the brand. Similar to Waverlys, but Gotohs will still remain my go-to tuners. The classical has an open po...
by Trevor Gore
Thu Jul 19, 2018 6:56 pm
Forum: The Gallery
Topic: 12 fret BRW small body
Replies: 22
Views: 6146

Re: 12 fret BRW small body

kiwigeo wrote:
Thu Jul 19, 2018 1:30 pm
Trevor, I assume the finish is hard shellac from Robert? You had no issues burning new shellac into the old finish?
This one was nitro all over, so no problems with drop fills.
by Trevor Gore
Wed Jul 18, 2018 9:36 pm
Forum: Instrument Builders Forum
Topic: Classical neck reinforcement. Yes or no?
Replies: 7
Views: 344

Re: Classical neck reinforcement. Yes or no?

It's worth looking at what might cause the various deformations of a neck over time. Broadly speaking, the direct loading is not much of an issue. Steel string guitars have smaller neck dimensions and higher string tensions and so the stress on a steel string neck is considerably higher. What is an ...
by Trevor Gore
Wed Jul 18, 2018 9:35 am
Forum: The Gallery
Topic: 12 fret BRW small body
Replies: 22
Views: 6146

Re: 12 fret BRW small body

I imagine it was falcate braced with CF so the top probably didn't move much but I wonder if it continued to compress a little? Did the saddle positions need lengthening at all? Did the truss have to be used to counter movement in the neck? The guitar looked pretty much in "as new" condition and ye...
by Trevor Gore
Wed Jul 18, 2018 12:24 am
Forum: The Gallery
Topic: 12 fret BRW small body
Replies: 22
Views: 6146

Re: 12 fret BRW small body

Five years later (where did that go!) and in for a service. Gets frequently gigged, but well looked after. Fixed the pre-amp (the main reason for the visit), tap tested, tweaked the set-up, sorted some dings in the finish, a cut and buff and good for many more years. sDSCF0649.jpg sDSCF0653.jpg And ...
by Trevor Gore
Thu Jul 12, 2018 8:37 pm
Forum: Instrument Builders Forum
Topic: Converting the 14 fret J45 drawings for 12 fret?
Replies: 2
Views: 218

Re: Converting the 14 fret J45 drawings for 12 fret?

I'd be keeping the body the same, but for a 12th fret neck join use the layout style of the falcate design, with fretboard overhang etc., depending on how many frets you want. The falcate design is a different scale length from the J45, so remember to correct for that so that you get the sound hole ...
by Trevor Gore
Sun Jul 01, 2018 10:33 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Bolt on bolt off neck - order of operations
Replies: 18
Views: 1208

Re: Bolt on bolt off neck - order of operations

There's a couple of things to think about... Decide how you want to seat the nut (Fig 5.3) then work from that and the position of the 14th fret. Don't assume that the scale length of the pre-cut board is the same as what's in the book! The "shoulder" line on the heel block needs to align with the 1...
by Trevor Gore
Sat Jun 30, 2018 12:54 pm
Forum: Instrument Builders Forum
Topic: Using Abalone
Replies: 15
Views: 1041

Re: Using Abalone

So do we have to get the shell inlay to exactly match the final surface of the top? Or is there a way of thinning it down, maybe with fine abrasives? And a follow up: how do we deal with the ineveitable small gaps? CA glue? So we have to flood with shellac first so as to not stain the spruce? Confu...
by Trevor Gore
Tue Jun 26, 2018 6:20 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Mass Support Block - Positioning
Replies: 4
Views: 391

Re: Mass Support Block - Positioning

You'd have to fill the guitar with coke to get the same weight as a couple of metal side weights :mrgreen: I guess the side masses will look a bit weird on the Xrays... 2nd anecdote: I was traveling with a guitar through LHR. Picked up the guitar at the baggage carousel and found a neat round hole ...
by Trevor Gore
Mon Jun 25, 2018 7:33 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Mass Support Block - Positioning
Replies: 4
Views: 391

Re: Mass Support Block - Positioning

does it matter if the additional weights applied to the sides are both on the same side of the guitar... I frequently use added mass only on one side, usually the treble side, so no problem there. ...and does it matter if one of them is not in the middle of the side but nearer the top (or back)? Th...
by Trevor Gore
Mon Jun 25, 2018 4:36 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Bolt on bolt off neck - order of operations
Replies: 18
Views: 1208

Re: Bolt on bolt off neck - order of operations

So, before gluing in the headblock, I could sand an approximate front to back angle, or I could just plane it when assembled in the mold. Best to just plane it in the mould, at least for your first. If you have everything sanded to fit the top dish, you know the geometry is heading the right way. T...
by Trevor Gore
Mon Jun 25, 2018 1:00 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Bolt on bolt off neck - order of operations
Replies: 18
Views: 1208

Re: Bolt on bolt off neck - order of operations

At the moment, the headblock is too long. However, I assume it will need to be 2 or 3 mm longer on the back to accomodate the curve of the back when sanding if we don't want to alter the depth of the sides from the dimension on the plan. Is that correct? Yes. Does the bolt on/off top plate also nee...