Search found 1490 matches

by Trevor Gore
Fri Jan 03, 2020 8:44 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: VA plots for tap test on plates
Replies: 13
Views: 1090

Re: VA plots for tap test on plates

Were any of the panels not flat enough?
by Trevor Gore
Wed Jan 01, 2020 12:06 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: VA plots for tap test on plates
Replies: 13
Views: 1090

Re: VA plots for tap test on plates

Fdiag should be an easy one to get, assuming you have the VA set up right. Hold the panel in the middle of the long side edge, tap lightly on a lower corner with the mic right behind the corner you tap. Often the problem is due to tapping too hard or not putting the mic where it can "hear" the vibes.
by Trevor Gore
Tue Dec 31, 2019 9:01 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Latest build final tap results
Replies: 1
Views: 170

Re: Latest build final tap results

That looks close enough to ideal to leave it as is. Well done, Chris!
by Trevor Gore
Mon Dec 23, 2019 1:03 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Unusual Panal Size
Replies: 6
Views: 438

Re: Unusual Panal Size

Sorry about the typo. Should have been p 4.39.
by Trevor Gore
Mon Dec 23, 2019 8:38 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Unusual Panal Size
Replies: 6
Views: 438

Re: Unusual Panal Size

For non-rectangular pieces, e.g. a rectangle with a corner cut off, choose a part of the panel that is rectangular and do a three point bend test on that part. Page 4.30 Design.
by Trevor Gore
Thu Dec 05, 2019 7:38 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Spectrum change with age
Replies: 5
Views: 722

Re: Spectrum change with age

I've found that if I use "old" wood (that I've had for at least 5 years), the guitar seems to get louder with age but the spectrum remains much the same. If I use "new" wood, cut and dried for less than 2 years, the guitar gets stiffer as it ages and whilst the shape of the spectrum remains recognis...
by Trevor Gore
Fri Nov 22, 2019 7:57 am
Forum: Instrument Builders Forum
Topic: Searching for Carbon Fiber for a Falcate Guitar Build
Replies: 4
Views: 747

Re: Searching for Carbon Fiber for a Falcate Guitar Build

These guys keep changing their name but are still in the same business and is where I've bought the CF products called for in the books. The cloth (1m wide) is much more economical to buy than tape (or was!). Give them a call and see if they still stock CF. https://allnex-brookvale.business.site/
by Trevor Gore
Wed Nov 20, 2019 9:45 am
Forum: Instrument Builders Forum
Topic: packaging tape for binding
Replies: 12
Views: 1256

Re: packaging tape for binding

I am looking for a source of the reinforced packaging tape to use for binding work...any recommendations? What are you using and do you find that the tape is strong enough by itself or do you still bind with stretchy cord or rubber as well? Cheers! Ross I use the two-way filament tape from these gu...
by Trevor Gore
Mon Nov 18, 2019 11:25 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Design Book
Replies: 1
Views: 412

Re: Design Book

Thanks for the kind words, Tom.
by Trevor Gore
Wed Nov 06, 2019 9:48 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Bridge Rotation at 2.3deg
Replies: 15
Views: 2027

Re: Bridge Rotation at 2.3deg

John, do the before and after tap responses tell you any more about what changes happened?
by Trevor Gore
Mon Nov 04, 2019 9:24 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Spectrum results
Replies: 3
Views: 948

Re: Spectrum results

Good to hear it all worked out. Well done!
by Trevor Gore
Sun Nov 03, 2019 10:03 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: My Second Build
Replies: 15
Views: 1987

Re: My Second Build

Your bridge looks the same size as mine (presumably made off the book drawings). Mine stay on! Them peeling off is as much about the bridge plate design as it is about the glue area, and you have the standard falcate bridge plate.
by Trevor Gore
Sat Nov 02, 2019 10:32 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Spectrum results
Replies: 3
Views: 948

Re: Spectrum results

95,170, 214 is a great result. Carving the back brace to reduce the T(1,1)1 and T(1,1)2 sufficiently will bring the T(1,1)3 down way too far and cause acoustics problems that you don't need because you no longer have the 4 semitone separation. Stringing up will possibly drop the T(1,1)2 a little bec...
by Trevor Gore
Mon Oct 28, 2019 8:25 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Bridge Rotation at 2.3deg
Replies: 15
Views: 2027

Re: Bridge Rotation at 2.3deg

I haven't spoken to Charles about a future class. Maybe an idea for another occasion!
by Trevor Gore
Sun Oct 27, 2019 10:14 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Bridge Rotation at 2.3deg
Replies: 15
Views: 2027

Re: Bridge Rotation at 2.3deg

Eric, there's the possibility of another class at Robbie's 10/11/12 Jul 2020. Please contact Robbie if you're interested.
by Trevor Gore
Sat Oct 26, 2019 10:30 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Bridge Rotation at 2.3deg
Replies: 15
Views: 2027

Re: Bridge Rotation at 2.3deg

My rotation ended up at 1.3 degrees... Let me refer you to this post from a while back: http://www.anzlf.com/viewtopic.php?f=33&t=6321&p=71613#p71613 Don't get too hung up on the bridge rotation if the modal frequencies and the monopole mobility are right. However, if the modal frequecnies are too ...
by Trevor Gore
Sat Oct 26, 2019 10:09 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: saddle location
Replies: 4
Views: 677

Re: saddle location

The problem I find is that leaving only1.2mm on the back of the saddle, 6th string, tends to lead to too much crushing and wear on the saddle, especially if Tusq is used. Obviously this is also a problem when using the traditional narrow saddle. As the contact point only ever moves forward as the br...
by Trevor Gore
Fri Oct 25, 2019 4:01 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: saddle location
Replies: 4
Views: 677

Re: saddle location

What am I missing? ...that I say in the last two lines of para 2 Section 20.3.2 (both editions) that you work it out for the string that has the shortest distance (typically the first string). The longest distance is typically ~ 3mm more, so that gives you ~2mm "land" of saddle on a 5mm saddle for ...
by Trevor Gore
Fri Oct 25, 2019 3:33 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Bridge Rotation at 2.3deg
Replies: 15
Views: 2027

Re: Bridge Rotation at 2.3deg

John, I've seen some seriously "roller-coaster" tops that have sounded fine, so that in and of itself doesn't appear to be sufficient criteria for less-than-best sound quality. Similarly, "print through" of the bracing pattern is pretty normal on highly responsive guitars. One of the things that I'v...
by Trevor Gore
Wed Oct 23, 2019 8:22 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: My Second Build
Replies: 15
Views: 1987

Re: My Second Build

DavidS wrote:
Tue Oct 22, 2019 8:09 pm
I am trying to figure out whether I am going to be able to achieve a finished T(1,1)2 close enough to 170Hz given I am starting at 180hz closed box.
Provided you remove very little wood on binding and clean-up and use a very low mass bridge (< 15 gms), you should be close.
by Trevor Gore
Sun Oct 20, 2019 10:12 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Paulownia fas bridge material?
Replies: 5
Views: 757

Re: Paulownia fas bridge material?

The Paulownia I've had is only one step removed from balsa and quite soft. I doubt it would hold up using the designs in the books. With some very cunning design work it might work, but I suspect some pretty complicated manufacturing would be required.
by Trevor Gore
Wed Oct 16, 2019 9:08 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Classical Bridges using CF
Replies: 16
Views: 1760

Re: Classical Bridges using CF

... Dimensions Fig 20-2 in the Build volume shows typical dimensions for the classical bridge with the height at 8mm Section 20.2 discusses the make up of the bridge and calls for three wood plies of 2,3 and 4mm thickness with two layers of CF between these plies. I haven't got the CF yet but it pr...
by Trevor Gore
Tue Oct 08, 2019 8:51 am
Forum: Instrument Builders Forum
Topic: RIP Graham Caldersmith
Replies: 3
Views: 1188

Re: RIP Graham Caldersmith

Sad news indeed. Graham was a pioneers in musical acoustics and guitar function, starting as an academic with a PhD in physics before moving to instrument making. One of the finest classical guitars I ever heard was one of Graham's. As Peter mentioned, a lot of the procedures and concepts in the boo...
by Trevor Gore
Sun Oct 06, 2019 12:37 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Frequency analysis GS Mini style build: improvement possible ?
Replies: 6
Views: 1001

Re: Frequency analysis GS Mini style build: improvement possible ?

It is almost impossible for me to determine what is going on from the pictures, but I suspect that some type of dipole activity was excited when you tapped with the back mass added; either because of the way you tapped on that occasion, or because the added back mass precipitated that type of respon...
by Trevor Gore
Sun Oct 06, 2019 12:24 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Tertiary braces -- need for carbon fiber?
Replies: 2
Views: 821

Re: Tertiary braces -- need for carbon fiber?

I have always put CF above and below all the braces. That doesn't mean that you have to...