Search found 1604 matches

by Trevor Gore
Mon Mar 18, 2024 8:47 am
Forum: Instrument Builders Forum
Topic: Carbon Fibre Threads
Replies: 3
Views: 101

Re: Carbon Fibre Threads

TallDad71 wrote:
Mon Mar 18, 2024 5:07 am
...I am certain that Trevor and Gerard are right to recommend adding Carbon Fibre but I can't work out why. Any guidance is gratefully received.
Design: Section 4.4.6, Paragraph 1.
by Trevor Gore
Tue Mar 12, 2024 8:37 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: 1st falcate build slowly underway.
Replies: 3
Views: 240

Re: 1st falcate build slowly underway.

Looking good, so far Jim.

If you pre-drilled the bridge pin holes (recommended) remember to stick tape over them when you do a tap test. It will give a better indication of where your resonances will end up.
by Trevor Gore
Wed Feb 07, 2024 3:26 pm
Forum: Instrument Builders Forum
Topic: Re: Modal Tuning Course, Melbourne Notice - Rescheduled
Replies: 3
Views: 15020

Re: Modal Tuning Course, Melbourne Notice - Rescheduled

Hello everyone, It became apparent that many people who wanted to attend the course had family commitments through January that precluded them from attending. Consequently, by popular demand, I have rescheduled the course to a couple of weeks after Easter, namely the 12th, 13th and 14th of April. Ot...
by Trevor Gore
Fri Feb 02, 2024 4:07 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Natural resonant frequency of uncoupled top
Replies: 6
Views: 1461

Re: Natural resonant frequency of uncoupled top

I guess one could say that, in the example above, the monopole mobility using 1/SQRT(Km) is 23.3, but the true MM = 1/SQRT((k + κA^2)m) is 20.0. Because the volume of the box and the area of the piston matter. Two guitars of different body dimensions but the same K and m, don't really have the same...
by Trevor Gore
Mon Jan 29, 2024 3:33 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Natural resonant frequency of uncoupled top
Replies: 6
Views: 1461

Re: Natural resonant frequency of uncoupled top

Any frequency you calculate, by whatever method, is only as valid as the assumptions under which the method was developed. Remember that the published 4-DOF model and input parameters was for a single specific guitar with the K and m values sized so that the model output matched that guitar's specif...
by Trevor Gore
Mon Jan 29, 2024 11:57 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Natural resonant frequency of uncoupled top
Replies: 6
Views: 1461

Re: Natural resonant frequency of uncoupled top

Basically, my question is: what is the meaning of the κA^2 term? Why is it included some times but not others? The simple answer is that MM is meant as a simple and useful way (i.e. not involving a huge amount of maths, or a detailed understanding thereof) of gaining a measure of the responsiveness...
by Trevor Gore
Fri Dec 22, 2023 1:37 pm
Forum: Instrument Builders Forum
Topic: Re: Modal Tuning Course, Melbourne Notice - Rescheduled
Replies: 3
Views: 15020

Re: Modal Tuning Course, Melbourne Notice - Rescheduled

Attention those who live in Melbourne, or don’t mind the travel: I will be running one of my 3 day Modal Tuning courses in Melbourne early next year. I’ve lost count of how many times I’ve run this course now, but probably close to 30 times, including 8 times in the USA. It has proved to be very pop...
by Trevor Gore
Sat Dec 09, 2023 10:00 am
Forum: Instrument Builders Forum
Topic: Spraying Hard Shellac
Replies: 8
Views: 29533

Re: Spraying Hard Shellac

....And yet another potential source of contamination is oil in the air from your compressor.
by Trevor Gore
Tue Nov 14, 2023 8:04 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: brace stress
Replies: 5
Views: 7392

Re: brace stress

My question is, can I use another method, not transforming the sections? Specifically, can I keep the dimensions as in the drawing, calculate the second moment of area around the neutral axis for each shape, and then multiply the panel Ipanel times Esitka and the total of the braces' I, Ibraces tim...
by Trevor Gore
Sun Nov 12, 2023 6:29 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: brace stress
Replies: 5
Views: 7392

Re: brace stress

Is there any reason it's not correct to do what I've just described: to multiply the I of part of the structure by one E, and the I of another part by different E, to get two EI's, and add them together? I haven't had the time to check out your spreadsheet, Greg, so apologies for that. However, whe...
by Trevor Gore
Sat Jul 29, 2023 1:24 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Nodes and anti-nodes
Replies: 7
Views: 25245

Re: Nodes and anti-nodes

kiwigeo wrote:
Fri Jul 28, 2023 8:26 pm
Trevor?
A somewhat cheesy explanation.
by Trevor Gore
Fri Jul 14, 2023 12:18 pm
Forum: Instrument Builders Forum
Topic: Nomad nut files
Replies: 9
Views: 31516

Re: Nomad nut files

kiwigeo wrote:
Fri Jul 14, 2023 9:12 am
How can this sort of mark up be justified???
Japarts seem to be selling sets of 3 files. Angkor are selling a set of 8 (and they're sold out!)
by Trevor Gore
Wed Jul 12, 2023 8:51 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Visual Analyzer Settings
Replies: 9
Views: 13942

Re: Visual Analyzer Settings

The "Run as administrator" thing is another of those XP to Win 7 conversion issues. As viruses and things proliferated, MS bumped up security levels, so only those with Administrator rights could do certain things, like save *.ini files, for example. Theses issues were, of course, addressed in the l...
by Trevor Gore
Mon Jul 10, 2023 7:25 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Visual Analyzer Settings
Replies: 9
Views: 13942

Re: Visual Analyzer Settings

That error message occurs on Windows 10 systems and likely Win 11, too. When I made the videos with Robbie I was using Win 7 on my computer, and the error message seems not to appear in Win 7, though the effects are there. As VA v9.0.6 was written for Win XP it was written to suit the input/output p...
by Trevor Gore
Wed Jul 05, 2023 12:35 pm
Forum: Instrument Builders Forum
Topic: Trouble Build
Replies: 20
Views: 130987

Re: Trouble Build

kiwigeo wrote:
Wed Jul 05, 2023 9:30 am
...Ive also got smoothing turned off...
That shouldn't create a problem.
johnparchem wrote:
Wed Jul 05, 2023 9:48 am
I get noise like that when I am clipping. The gain being too high.
Definitely worth investigating.
by Trevor Gore
Wed Jul 05, 2023 8:29 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Visual Analyzer Settings
Replies: 9
Views: 13942

Re: Visual Analyzer Settings

Good day, I had to update my laptop which runs iOS 11. Windows 11? VA won't run on Apple/Mac systems. VA version 9.0.6 was built for Win XP which has different I/O requirements from Windows 10 (Win 11 I'd expect to be much the same as Win 10, but I haven't tested it). 9.0.6 runs fine on Win 10. Ins...
by Trevor Gore
Tue Jul 04, 2023 10:42 pm
Forum: Instrument Builders Forum
Topic: Trouble Build
Replies: 20
Views: 130987

Re: Trouble Build

Those are fairly nasty looking VA plots, Martin. Lots of background noise or something else going on?
by Trevor Gore
Tue Jul 04, 2023 8:43 am
Forum: Instrument Builders Forum
Topic: Trouble Build
Replies: 20
Views: 130987

Re: Trouble Build

Neck relief? Back buzz? Truss rod? Loose neck attachment hardware? Pick-up if fitted?
by Trevor Gore
Sat May 27, 2023 2:44 pm
Forum: Instrument Builders Forum
Topic: Chladni and VA tests ???
Replies: 61
Views: 79201

Re: Chladni and VA tests ???

The neck can be involved in some modes, so its best to have it free. The neck is permanently connected. It’s like a modern Spanish heel connection I’ve been doing to complicate my life more! When I said free, I meant not clamped in a vise! Basically, try to mimic the conditions the guitar is in whe...
by Trevor Gore
Sat May 27, 2023 10:53 am
Forum: Instrument Builders Forum
Topic: Chladni and VA tests ???
Replies: 61
Views: 79201

Re: Chladni and VA tests ???

Generally, you have to excite where you expect an antinode to be, which helps reduce the power requirement. Google up some pictures of Chladni patterns and that will give you an idea of where those are. There are pics in the book, too, of course. The monopole at at 356 Hz is unusual. I suspect you a...
by Trevor Gore
Sat Apr 22, 2023 1:52 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: eBook edition?
Replies: 16
Views: 29148

Re: eBook edition?

Kitwn wrote:
Sat Apr 22, 2023 9:02 am
Trevor,
Any indications of when copies will be available? There must be quite a waiting list by now.
Unfortunately, my crystal ball is no better than Philip Lowe's.
by Trevor Gore
Sun Apr 16, 2023 10:54 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: eBook edition?
Replies: 16
Views: 29148

Re: eBook edition?

Sorry, there won't be an eBook edition.
by Trevor Gore
Fri Mar 17, 2023 8:56 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Win 10 +usb mic
Replies: 6
Views: 12238

Re: Win 10 +usb mic

Good to hear!

File Explorer:

Keyboard shortcut is Windows key + e

or the long way is Start (Programs list)/ Windows System/File Explorer (then drop a shortcut onto your task bar)
by Trevor Gore
Thu Mar 16, 2023 8:36 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Win 10 +usb mic
Replies: 6
Views: 12238

Re: Win 10 +usb mic

Once you get behind the Win 10 GUI, you'll find that things look a lot like Win 7.
by Trevor Gore
Wed Mar 15, 2023 9:28 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Win 10 +usb mic
Replies: 6
Views: 12238

Re: Win 10 +usb mic

I have an Audio-Technica ATR 2100-USB mic which works fine on Win 10 and Win 7, plugging straight into the computer. This mic can be connected as either an XLR dynamic mic or as a USB mic and works fine with either connection (mic socket or USB). The problem is likely with Win 10 not recognising the...