Search found 103 matches

by Jim watts
Wed Mar 13, 2024 4:22 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: 1st falcate build slowly underway.
Replies: 3
Views: 296

Re: 1st falcate build slowly underway.

:D Thanks, keeping blops of epoxy of the top is a major win :)
I did have the holes taped up, you can hear the difference too. Thanks for the reminder, it’s little details like that are easy to forget.
by Jim watts
Sun Mar 10, 2024 5:18 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: 1st falcate build slowly underway.
Replies: 3
Views: 296

1st falcate build slowly underway.

I've been using Trevor's books for a while now, mostly on traditional classical builds. They turn out really well, so I thought I owed it to myself to try a falcate build. This is a 12 fret 000 steel string. It's moving slow as I have another guitar I need to be working on. well, and I'm slow! Here ...
by Jim watts
Mon Apr 24, 2023 9:34 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: eBook edition?
Replies: 16
Views: 29787

Re: eBook edition?

And you get 50% off books and plans.
by Jim watts
Tue Mar 21, 2023 8:19 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Laying out a 12 fret 000 with falcate bracing
Replies: 1
Views: 8056

Laying out a 12 fret 000 with falcate bracing

As the topic suggest I'm trying to mash together Trevors book plan with a Martin 12 fret 000. I notice that when lining up the 12 fret body joint Trevors soundhole is shifted approximately 32mm forward (towards the body joint) this would allow for 18 frets without extending the fingerboard into the ...
by Jim watts
Fri Oct 14, 2022 10:02 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Curious about a mode at 146-ish Hz
Replies: 11
Views: 16035

Re: Curious about a mode at 146-ish Hz

Thanks for the thoughts. Dave, I was looking at some taps of another guitar, Also a Hauser size 7 Fan guitar. It has it too. I also has a tap saved of that with the sound hole plugged and it appears to be the first response with the sound hole plugged. Trevor, I tried to get a spectra plot of tha mo...
by Jim watts
Thu Oct 06, 2022 11:03 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Curious about a mode at 146-ish Hz
Replies: 11
Views: 16035

Re: Curious about a mode at 146-ish Hz

Whatdaya know, I can attach a gif.
mode_146.2Hz.gif
mode_146.2Hz.gif (834.68 KiB) Viewed 16008 times
by Jim watts
Thu Oct 06, 2022 10:26 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Curious about a mode at 146-ish Hz
Replies: 11
Views: 16035

Re: Curious about a mode at 146-ish Hz

I think having the speaker off to the side is responsible for that. The mode actually sweeps across the top. If I could post a .gif I can show you.
by Jim watts
Wed Oct 05, 2022 2:05 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Curious about a mode at 146-ish Hz
Replies: 11
Views: 16035

Curious about a mode at 146-ish Hz

I was fortunate enough the other day to have a guitar scanned with a laser vibrometer. I viewed it as an opportunity to check my tap results. They actually line up pretty nicely. One oddity I struggled with is that most of my taps have a broad peak around 150 Hz or so. I've always thought it as an a...
by Jim watts
Sat Sep 10, 2022 1:33 am
Forum: Instrument Builders Forum
Topic: Running VA software with Windows 11
Replies: 3
Views: 2636

Re: Running VA software with Windows 11

I am running it on windows 11. Seems to be fine.
by Jim watts
Fri Sep 09, 2022 5:31 am
Forum: Instrument Builders Forum
Topic: The Caldersmith Papers
Replies: 6
Views: 20292

Re: The Caldersmith Papers

I understand that Graham Mc. had some difficulties obtaining permission to publish a number of papers jointly authored by Graham C. and Tom Rossing. Prof. Thomas Rossing was one of the greats of musical acoustics and a friend to many, including me. It is with considerable sadness that I have to rep...
by Jim watts
Wed Jul 06, 2022 7:34 am
Forum: Instrument Builders Forum
Topic: Bluetop35
Replies: 10
Views: 7724

Re: Bluetop35

Really a nice job!
by Jim watts
Sat Apr 16, 2022 12:53 pm
Forum: Instrument Builders Forum
Topic: Slow progress on the neoclassical
Replies: 10
Views: 6700

Re: Slow progress on the neoclassical

That's looking really good!
by Jim watts
Sun Apr 10, 2022 12:13 pm
Forum: Instrument Builders Forum
Topic: new classical with spectrum
Replies: 8
Views: 7484

Re: new classical with spectrum

Hi Mark, I have a couple of photos. The things that helped me most were a wide super sharp chisel, 25mm was my widest, a marking template that can very accurately mark the joint all around the neck and a highly repeatable clamping method for test fitting and final glue up. The photo below is my mark...
by Jim watts
Sat Apr 09, 2022 12:22 pm
Forum: Instrument Builders Forum
Topic: new classical with spectrum
Replies: 8
Views: 7484

Re: new classical with spectrum

Thanks for the nice words guys!
by Jim watts
Mon Mar 28, 2022 1:30 pm
Forum: Instrument Builders Forum
Topic: new classical with spectrum
Replies: 8
Views: 7484

new classical with spectrum

Just complete this. Honduran Rosewood and spruce 7 fan open harmonic bar classical A v-joint on the head stock which was something I've been working on I'm pretty happy with it as it sounds and plays pretty nice. I was pleased that I was able to get the spectrum into the range I was shooting for. IM...
by Jim watts
Tue Mar 01, 2022 5:52 am
Forum: Instrument Builders Forum
Topic: How to remove these marks?
Replies: 6
Views: 7167

Re: How to remove these marks?

I'd probably bleach it and the add some tint to the lacquer to add a little color back, or possible stain the neck if you're finishing from rattle cans.
by Jim watts
Tue Jan 11, 2022 2:59 pm
Forum: Instrument Builders Forum
Topic: vacuum press
Replies: 10
Views: 7128

Re: vacuum press

Here's one I made some time back. I used a closed cell rubber foam for the seal.
vacuum frame.JPG
vacuum frame.JPG (51.29 KiB) Viewed 7056 times
by Jim watts
Sat Jan 01, 2022 6:24 am
Forum: Instrument Builders Forum
Topic: My shellac looks like gravy
Replies: 9
Views: 5719

Re: My shellac looks like gravy

Are you sure your shellac is dewaxed?
I tend to use Kusmi buttons which are not dewaxed, it looks like a milky caramel color until I separate the wax out by filtering it though coffee filters a few times after it's dissolved.
You might try filtering it and see what it looks like.
by Jim watts
Thu Nov 18, 2021 2:54 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Air, Top and Back Resonances, Coupled and Uncoupled - Untensioned?
Replies: 17
Views: 41076

Re: Air, Top and Back Resonances, Coupled and Uncoupled - Untensioned?

Oi has it right. The modulus of elasticity of the material is fixed, but the section modulus changes with shape, your saw example is great.
Total stiffness is the material modulus x section modulus.
by Jim watts
Wed Nov 17, 2021 3:27 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Air, Top and Back Resonances, Coupled and Uncoupled - Untensioned?
Replies: 17
Views: 41076

Re: Air, Top and Back Resonances, Coupled and Uncoupled - Untensioned?

I have a build going right now that I temporarily glued the bridge on using hide glue and masking tape. I put tape down on the top and glued the bridge to that. I'm not sure it really mimic's the stiffness due to the tape but the weights right and certainly has some stiffness and it was easy to do. ...
by Jim watts
Sun May 09, 2021 7:53 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Confused about frequency response in my first TG style falcate
Replies: 20
Views: 24944

Re: Confused about frequency response in my first TG style falcate

Trevor Gore wrote:
Sat May 08, 2021 5:39 pm
Nice guitar, Martin.
.......
Your tap responses are very clean, by the way, so well done there. As many have a lot of trouble getting clean plots, would you like to share how you did that? TIA.
Please!
by Jim watts
Wed Mar 31, 2021 2:48 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Can you derive a freq plot from a sound clip?
Replies: 8
Views: 8992

Re: Can you derive a freq plot from a sound clip?

John, That's an interesting experiment, Thanks for posting it.
Pretty cool!
by Jim watts
Sun Mar 28, 2021 2:31 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Can you derive a freq plot from a sound clip?
Replies: 8
Views: 8992

Re: Can you derive a freq plot from a sound clip?

I don't have any idea how to do it, but it seems filtering out the frequencies of know musical notes might be a place to star. Or, perhaps set filters that'll only let frequencies pass in the ranges your interested in, minus the musical notes (I'm assuming the instrument doesn't have a natural reson...
by Jim watts
Wed Mar 03, 2021 10:35 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Mono mobility (Martin and my TG style) results
Replies: 16
Views: 15782

Re: Mono mobility (Martin and my TG style) results

I find this to be a very interesting and appreciate your posting it here. While I don’t have the answers your looking for I would like say that even if you matched the numbers for these modes, you guitar would still sound different. I also think that this is a fairly obvious statement so I apologize...