Search found 1604 matches
- Thu Feb 23, 2023 8:13 am
- Forum: Instrument Builders Forum
- Topic: Repairers in Darwin
- Replies: 5
- Views: 3548
Re: Repairers in Darwin
You could try Jim Scofield, Darwin Strings and see if he is interested. Jim has been a frequent contributor to the forum.
- Tue Feb 14, 2023 8:08 am
- Forum: Instrument Builders Forum
- Topic: Action & relief for C# open setup
- Replies: 6
- Views: 6992
Re: Action & relief for C# open setup
The amplitude of oscillation is entirely dependent on the pluck displacement. Of course, it takes less force to displace a lower tension string for the same oscillation amplitude of a higher tension string. For the same feel you have to go to a higher tension string set, i.e. heavier strings, which ...
- Mon Jan 16, 2023 7:32 pm
- Forum: Instrument Builders Forum
- Topic: Heelless neck joint
- Replies: 8
- Views: 8513
Re: Heelless neck joint
Not my idea, and no pictures, but you could do a tapered sliding dovetail into what I call the neck block top plate, with a single screw accessible from inside to stop it unplugging. Fully fit the dovetail before you glue the fret board on.
- Mon Jan 16, 2023 8:43 am
- Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
- Topic: Vibrational stiffness freq for ukulele?
- Replies: 4
- Views: 10395
Re: Vibrational stiffness freq for ukulele?
You might find some relevant information in this thread. Otherwise, try to track down Clancy.
- Wed Dec 07, 2022 8:25 pm
- Forum: Instrument Builders Forum
- Topic: Frets causing back bow
- Replies: 8
- Views: 11819
Re: Frets causing back bow
My fret saw is 0.5mm, my fret tangs are 0.5mm wide so why when I install the Frets do I get a back bow on my fretboard I wonder? I'm guessing that the 0.5mm measurement doesn't include the barbs (or the frets would just fall out). The barbs will force a bit of back bow, especially if you're frettin...
- Sun Oct 16, 2022 11:34 am
- Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
- Topic: Top thicknesses :)
- Replies: 6
- Views: 12641
Re: Top thicknesses :)
The deflection method will also not work on those. Is there any way to still use them? It's still possible to use the deflection method if the cupping is not too bad. Basically, pre-load the panel with enough weight to flatten the cupping, zero the deflection gauge, then add more weights to take th...
- Sat Oct 15, 2022 11:04 am
- Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
- Topic: Top thicknesses :)
- Replies: 6
- Views: 12641
Re: Top thicknesses :)
At the moment my guess is there was some problem with the tap testing. Some of those tops were slightly bent in the short axis (cross grain) while being totally straight in the long grain direction. That would explain things. Cupping across the grain will make the long grain Young's modulus measure...
- Thu Oct 13, 2022 7:18 am
- Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
- Topic: Live back too low when uncoupled
- Replies: 8
- Views: 11129
Re: Live back too low when uncoupled
Gluing fiber carbon over a X-Brace to increase stiffness would be an option? I don’t know if anyone tried before. See page 11-12 in the Build book. What is the consequences of having the main frequency too low? "Low" is a matter of taste. The lower you take the main resonances, the more bass you ge...
- Tue Oct 11, 2022 9:25 pm
- Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
- Topic: Live back too low when uncoupled
- Replies: 8
- Views: 11129
Re: Live back too low when uncoupled
If the back has the radial bracing plus main brace over lower bout then you have the option of reducing stiffness of the back by taking material out of the centre of the back brace. That's correct, but reducing the stiffness will reduce the T(1,1) 3 frequency. The OP wants to raise it. To raise sti...
- Tue Oct 11, 2022 9:11 pm
- Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
- Topic: Curious about a mode at 146-ish Hz
- Replies: 11
- Views: 16034
Re: Curious about a mode at 146-ish Hz
That's an interesting mode, Jim! All I can think of is that it might be a "corpus" mode, and maybe asymmetrical because of the offset excitation. The first corpus mode is the marimba bar mode of the whole guitar. It has a node usually somewhere between the nut and first fret with the other node bein...
- Tue Oct 11, 2022 8:57 pm
- Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
- Topic: Top thicknesses :)
- Replies: 6
- Views: 12641
Re: Top thicknesses :)
Jurgen, I put your numbers through my spreadsheet and got 3.15mm for the Sitka (twice) and 3.22mm for the Engelmann. So I suspect you may have got the data entry wrong on the Sitka, unless the data you posted is your actual spreadsheet, in which case something really weird is happening. As for alway...
- Tue Sep 27, 2022 8:53 am
- Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
- Topic: Tap testing the panels - help, what am I seeing?
- Replies: 2
- Views: 8630
Re: Tap testing the panels - help, what am I seeing?
The cross grain mode is definitely the most difficult to get. However, the thickness result does not depend very heavily on it, which I guess is the good news! I hold the panel about a third of the way down the long edge and tap at the same level down with the mic immediately behind the tap position...
- Sat Sep 10, 2022 8:44 am
- Forum: Instrument Builders Forum
- Topic: Running VA software with Windows 11
- Replies: 3
- Views: 2636
Re: Running VA software with Windows 11
VA will run on anything from Win XP to Win 11. I still use v. 9.0.6, which has a couple of draw-backs listed here , but these are less hassle (to me) than using later versions. After XP, for v. 9.0.6 the mic levels need to be set up in Windows, as after XP the Windows I/O protocol changed which is t...
- Wed Sep 07, 2022 10:39 pm
- 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 repo...
- Tue Aug 23, 2022 8:37 am
- Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
- Topic: Wood species for Falcate braces
- Replies: 37
- Views: 56128
Re: Wood species for Falcate braces
I recently bent some Engelmann spruce into falcate braces - by far the easiest spruce I've ever bent. That was the first time I've tried bending Engelmann, so I don't know if that is representative of the species. What's the general experience of bending Engelmann by you falcaters out there?? Thanks.
- Tue Aug 02, 2022 8:30 am
- Forum: Instrument Builders Forum
- Topic: Epoxy, brushes, CF tow, oh my!
- Replies: 10
- Views: 6166
Re: Epoxy, brushes, CF tow, oh my!
It's best not to buy tow, but to buy cloth and pull threads from the cloth. The cloth spec. is in the book. I get mine from these guys: https://allnex-brookvale.business.site/ . I use artist brushes from Bunnies or try a $2 shop. Use WEST epoxy, 105 resin and 207 hardener (the 207 can be used when g...
- Sat Jul 30, 2022 11:00 am
- Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
- Topic: DIY Sig Gen/Amp unit for Chladni patterns
- Replies: 33
- Views: 139844
Re: DIY Sig Gen/Amp unit for Chladni patterns
- Thu Jul 28, 2022 7:59 am
- Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
- Topic: DIY Sig Gen/Amp unit for Chladni patterns
- Replies: 33
- Views: 139844
Re: DIY Sig Gen/Amp unit for Chladni patterns
On the note of people blowing their speakers I was wondering if you think this Griffin signal generator with amplifier will work? Hard to say, Dave. The specs just say sig gen and amplifier. A bit like saying car with engine. See if you can get more detail out of Griffin, such as frequency range an...
- Wed May 11, 2022 8:23 am
- Forum: The Gallery
- Topic: Figured Koa Acoustic
- Replies: 7
- Views: 12337
Re: Figured Koa Acoustic
Nice work! Definitely one for "The Book" gallery!
The guy who inspired your rosette was "Tricky Fish".
The guy who inspired your rosette was "Tricky Fish".
- Tue Apr 26, 2022 8:25 am
- Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
- Topic: Un-coupled top frequency
- Replies: 2
- Views: 10066
Re: Un-coupled top frequency
Hello, I'm determining the monopole mobility of a just finished steel string. I need to find the UN-coupled tops main frequency. The strings are off, and the sound hole is plugged with a cut off sour cream container. When I tap it into the analyzer with no saddle or bridge pins I get 188hz. With a ...
- Fri Apr 01, 2022 8:29 am
- Forum: Instrument Builders Forum
- Topic: Applying G&G techniques to a kit guitar
- Replies: 14
- Views: 8937
Re: Applying G&G techniques to a kit guitar
The main reason for routing the saddle slot after gluing down the bridge is because the bridge is pre-positioned by the bridge pin holes on falcate braced designs, as there is little latitude for error due to the proximity of braces if the pin holes are drilled in the closed box. If you have the rig...
- Fri Mar 11, 2022 8:21 am
- Forum: Instrument Builders Forum
- Topic: 0 Taper Bridge Pins
- Replies: 19
- Views: 13147
Re: 0 Taper Bridge Pins
They also have no taper at all, the shaft measures 4.7mm the whole length. As such, neither my 4.5mm or 5mm drill bits are suitable... 4.7mm is 3/16". You should have no trouble finding a 3/16" drill if you want to use the supplied pins. A 3/16" drill is also a good size to use as a pilot hole for ...
- Wed Mar 02, 2022 3:13 pm
- Forum: Instrument Builders Forum
- Topic: Saddle Compensation
- Replies: 10
- Views: 5829
Re: Saddle Compensation
Hi Trevor, thanks for the response mate, You will note that I simply excluded the 3mm for nut compensation in my calculation, does that now make my numbers correct? Definitely not! Adding nut compensation, in very approximate terms, halves the amount of saddle compensation you need. So just excludi...
- Wed Mar 02, 2022 9:15 am
- Forum: Instrument Builders Forum
- Topic: Saddle Compensation
- Replies: 10
- Views: 5829
Re: Saddle Compensation
Steel string, Falcate braced, 645.2mm Scale Length, no Nut Compensation. I have read and re-read sections pertaining to Saddle Compensation and I am terribly confused about Saddle Location. If I use a 5mm Saddle, straight not slanted, the front of the saddle slot should be (from page 20-19, section...
- Fri Jan 21, 2022 7:56 am
- Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
- Topic: Intonation Problem
- Replies: 10
- Views: 16000
Re: Intonation Problem
I've not applied any more thought to this (a bit busy at the moment), but have you got some sort of tail piece resonance going on?