Search found 1092 matches

by Dominic
Sun Sep 23, 2012 1:15 pm
Forum: Instrument Builders Forum
Topic: Brushing epoxy
Replies: 11
Views: 6715

Brushing epoxy

Hey, I have usually used a old credit card to spread epoxy and then sand it back to wood. But I end up with some sinking of the finish into grain lines after about 6 months. So reading the Gore/Gilet book Trevor suggests brushing the epoxy and leveling it so I thought I'd give this a try. My first o...
by Dominic
Sun Sep 23, 2012 1:06 pm
Forum: Instrument Builders Forum
Topic: Help with Plane Selection
Replies: 5
Views: 3758

Re: Help with Plane Selection

http://www.leevalley.com/US/wood/page.a ... 1182,52515

I recently got one of these and its lovely. I see they are now selling with the new super duper blade. I think it is still cheaper to get them from LeeValley than CT.
Dom
by Dominic
Sun Sep 23, 2012 10:02 am
Forum: Instrument Builders Forum
Topic: Australia Handmade Guitar - Trying to locate the Maker!!!
Replies: 6
Views: 4702

Re: Australia Handmade Guitar - Trying to locate the Maker!!

J.F. Custom wrote:
As a side, I see the headstock inlay as a Ginko Branch... Clue perhaps??

Jeremy.
Or a Scottish thistle
by Dominic
Sat Sep 22, 2012 2:44 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: 4 DOF Model
Replies: 106
Views: 79678

Re: 4 DOF Model

Hi Trevor, I suspect it is something to do with the rules and how we apply them to Dbar. I am still trying different things. I've got your 100Hz numbers to work at.
Thanks for your help so far. I'll crack this eventually.
Cheers
Dom
by Dominic
Fri Sep 21, 2012 8:09 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: 4 DOF Model
Replies: 106
Views: 79678

Re: 4 DOF Model

Well I have spent days and nights on this and it does not seem to matter which way we calculate Dbar it comes out the same and Os and I are getting the same results. I built the calculations from scratch using the equations in the book as a guide. So we have arrived at this outcome independently. Bu...
by Dominic
Fri Sep 21, 2012 11:49 am
Forum: Jigs & Fixtures
Topic: Correcting/stopping Neck warp?
Replies: 4
Views: 5692

Re: Correcting/stopping Neck warp?

Heat and clamps
by Dominic
Tue Sep 18, 2012 10:12 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: What would you call these modes
Replies: 12
Views: 9420

Re: What would you call these modes

Nice set up to get such clean lines at those high frequencies Marty. I wonder if there is a frequency that would outline all the braces?. You got a ubeaut analogue one from that guy didn't you? My sig gen works great but I only have a shitty little component amp and need something cleaner and more p...
by Dominic
Tue Sep 18, 2012 9:46 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: 4 DOF Model
Replies: 106
Views: 79678

Re: 4 DOF Model

Don't worry Os, I'll track down the problem. I think of it this way, once I have got equations working for all the models in the book there are none left to do and its a real buzz getting it to work. I've finished to intonation spreadsheet and just need to load a set of strings and run it. So this m...
by Dominic
Tue Sep 18, 2012 1:26 pm
Forum: Instrument Builders Forum
Topic: Another Newbie - Newcastle
Replies: 25
Views: 15464

Re: Another Newbie - Newcastle

Yeah, I found the Kinkead book really useful for my first guitar. He steers a nice line through the subject and does not digress too much so you get just what you need and nothing else. The only thing you would do differently is use radius dishes for the top and back. But he steps through the proces...
by Dominic
Mon Sep 17, 2012 8:00 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: 4 DOF Model
Replies: 106
Views: 79678

Re: 4 DOF Model

Hey Os, I'm about half way through recalculating everything. I've written out the equations in mathtype directly from the book then create new formulas based on those specifications for each variable then checking against your workbook. Once I have equations for one frequency I'm happy with I'll cop...
by Dominic
Mon Sep 17, 2012 7:40 am
Forum: Instrument Builders Forum
Topic: Exporting a guitar, safest option.
Replies: 22
Views: 11521

Re: Exporting a guitar, safest option.

I've travelled twice OS with a guitar in baggage not in overhead. Hard shell case made of fibre glass not abs. Once to Washington in the US and once to Warsaw in Poland So 2 pretty long flights with serveral domestic changes to link up with other planes. Its the domestic legs I had trouble with but ...
by Dominic
Mon Sep 17, 2012 7:01 am
Forum: Instrument Builders Forum
Topic: Acoustic bass specs
Replies: 16
Views: 9826

Re: Acoustic bass specs

So while everyone seems to agree that a large air cavity is good for a bass, can anyone explain why? What are the attributes of a large air cavity that helps support the lower notes and that can not be gained by reducing the relative sound hole radius. Using the Gore framework I can't see how this c...
by Dominic
Sun Sep 16, 2012 6:35 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: 4 DOF Model
Replies: 106
Views: 79678

Re: 4 DOF Model

Cool thanks Trevor. I did read through all your posts again carefully after I had asked the question and I found those two quotes but I am not allowed to edit my own posts ...for it is written. Too many late nights playing with excel and my brain needed a break to gain some perspective. Now I can vi...
by Dominic
Sun Sep 16, 2012 5:10 pm
Forum: Instrument Builders Forum
Topic: Acoustic bass specs
Replies: 16
Views: 9826

Re: Acoustic bass specs

Cool thanks Graham. I'd love to see your notes at some stage.
Still a bit cold here in Canberra so I would not be rushing home from Italy just yet.

Cheers
Dom
by Dominic
Sun Sep 16, 2012 5:06 pm
Forum: Instrument Builders Forum
Topic: Acoustic bass specs
Replies: 16
Views: 9826

Re: Acoustic bass specs

Thanks Phil, I am more along for the intellectual stimulation but like everyone, an acoustic bass is on my list somewhere. The article I read about them said basically what you said, most of these basses are not very good. And whoever it was said they were having good results using lighter braced sm...
by Dominic
Sun Sep 16, 2012 1:11 am
Forum: Instrument Builders Forum
Topic: Acoustic bass specs
Replies: 16
Views: 9826

Acoustic bass specs

Hey, was talking with craig about an acoustic bass he is planning on building and it got me thinking about the design. conventional 'wisdom' says an acoustic bass should have a large deep body, extra bracing and a thicker top. But more recently I have read that 4 string bass guitars can be built a l...
by Dominic
Sun Sep 16, 2012 12:00 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: 4 DOF Model
Replies: 106
Views: 79678

Re: 4 DOF Model

Yes, history has not done us any favours with the nomenclature. Really, the i or j operator (depending on whether you are an electrical engineer or not) should be a sign like "+" or "-", at least for engineering applications. Anybody who teaches that j is the SQRT(-1) has no understanding of the co...
by Dominic
Sat Sep 15, 2012 9:22 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: 4 DOF Model
Replies: 106
Views: 79678

Re: 4 DOF Model

Thanks Trevor, along with Os' question of how to turn an imaginary number into something we can use, I just want to clarify the following. When we calculate the Di's for each increment, do we also need to do the same with the Ys or are they in effect, constants associated with the top, back, sides a...
by Dominic
Sat Sep 15, 2012 3:40 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: 4 DOF Model
Replies: 106
Views: 79678

Re: 4 DOF Model

There is a permanence about the word doomed that I refuse to concede to so I take it back. I’ll get this worked out one way or another. I was asking about producing columns of real numbers, one for each Da Db Dt Ds at each freq increment. Now I get that this is not what happens. People say economist...
by Dominic
Sat Sep 15, 2012 3:16 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Test data for intonation spreadsheet
Replies: 28
Views: 20726

Re: Test data for intonation spreadsheet

Thanks Trevor, I'm nearly done but a lot of this stuff is new to me, not the math but the terms and how they compare and how this stuff behaves. But I am close
Cheers
Dom.
by Dominic
Fri Sep 14, 2012 9:52 pm
Forum: Instrument Builders Forum
Topic: Introductions - a polite request
Replies: 54
Views: 34913

Re: Introductions - a polite request

Hey you know what, we've got all these new blokes wondering around eating snags and drinking beer and we know who they are but they don't know who we are. Perhaps it would be worth all of us doing a brief who am I and were is my shop. OK, names Dominic, originally from Margaret River in WA where I w...
by Dominic
Fri Sep 14, 2012 9:30 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: 4 DOF Model
Replies: 106
Views: 79678

Re: 4 DOF Model

Hi Trevor, I have been chatting with Os about the model this week and I ended up sitting here at 4.00am this morning reading and playing with the spreadsheet. So the sooner I/we get this worked out the soon I will be able to go to bed. Now, previously you mentioned calculating all the Di,s for each ...
by Dominic
Thu Sep 13, 2012 3:34 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: 4 DOF Model
Replies: 106
Views: 79678

Re: 4 DOF Model

Hey Os, nice work on getting this far. First one to get the model working that I know of. I have my sights set on getting it up and working but have not read that bit enough yet. But as guide to those of us behind you, could I suggest that when you ask questions, put down the page number or the equa...
by Dominic
Thu Sep 13, 2012 2:26 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Test data for intonation spreadsheet
Replies: 28
Views: 20726

Re: Test data for intonation spreadsheet

Hey Trevor or Martin (munchkin), in calculating the mass per unit length of a string, eq 4.7-34, is the L variable the L derived from eq 4.7-32? Or is it just the length of the rig? Also, what units are all the measurements in? I think I am having issues with putting everything in the right form. I ...
by Dominic
Wed Sep 12, 2012 6:46 pm
Forum: Instrument Builders Forum
Topic: KiwiGeo's Polite Request
Replies: 3
Views: 2330

Re: KiwiGeo's Polite Request

Hey Os, welcome, you will find lots of answers here and lots of help. The design and build thread is a beauty. A lot of the easier stuff has been worked out and solutions and tips posted. So have a go at the thickness equation and see how you go. A lot of the questions you may have have probably alr...