Australian/New Zealand Luthiers Forum

Anyone still awake in Oz? What glue bonds best to Titebond I? That is a joint previously glued with Titebond. Need to reglue a binding gap in the next 30 minutes. No pressure! I've used Titebond for this in the past but I gather now this is not such a good idea. CA? Write a search parameter on this ...

Extraordinary! Stunningly beautiful! Thanks for posting the acoustic design details and especially of how you handled the koa top, very interesting. If you don't mind me asking, can you go into how you did the rope binding? I've used small rope binding, (3mm x 2mm) which was a layup of stacked venee...

Stumbled across this thread today, thought I would update with my current version. Modification is in the feet which sit on the guitar top. The 10mm x 30mm x 60mm feet can pivot a little, with friction, in the slots and have small cork pads at the ends, so each foot sit on two points only. This make...

I use the Cumpiano method and have not had a problem. It is important to have plenty of tenon and the cross dowel holes drilled as close to the root of the tenon as you can. My tenon's are 20mm thick by 25mm long. I use a 10mm cross dowel, leaving 15mm of wood. I occasionally use threaded insets, mo...

Okay, next stop Chladniville. It seems worthwhile to figure out the area to mass ratio, at least visually if not mathematically. I have yet to get a working Chladni setup going. My latest effort is not producing enough volume to excite the tea leaks. I'm putting out 98 dB, but tea leaves just sit th...

Chladni newbie here. Any idea how many decibels one needs to crank out to make Chladni patterns? I ask because I'm generating tones on a computer, sending them out to one channel of a 2x40 watt amp and an 8 ohm 4" speaker rated for 40 watts. Volume on the sound card and amp are maxed. At 229hz, I me...

Thanks Trevor, this is all very helpful. Am I correct to think the effective area is every bit as important as the mass of that area. That is, for equal effective mass, a larger effective area will radiate more sound, yes? Is Chladni testing the only means of quantifying the effective area independe...

One more.... Given the vagaries of whether a top is coupled to the back and phase cancellation method of "uncoupling" the top from the back, does simply dampening the back by holding it against my chest as I tap the top, (along with plugging the soundhole) insure the top is uncoupled? Maybe this int...

Maybe another way of asking this is whether effective mass equates to effective area (of sound board) somehow and if nothing else changes, if effective mass goes down, has the effective area reduced as well? Effective mass going down sounds like a good thing, but effective area going down does not. ...

Hi, Trying to understand effective mass as it applies to the top's Monopole Mobility. In my most recent guitar, I ran the equation on the top while glued to the sides and clamped in the side mold, no back. Once the back was on, ran the same, not clamped in the mold. Other than the back and removal o...

Any idea why this occurs? Haven't had the problem on my own, but see it fairly often and have been asked to repair several times. Do people build them this way? I doubt it. Does it happen do to changes in climate some how? Age? Neck and body stresses? I'd be interested in ideas on this.

The tiles themselves are 3.2mm x 3.2mm before they are rounded over. There is a veneer on either side of them to help hold them together while bending. One side is Koa, the other is black veneer. Pick the side you want to keep for a fine accent line. I just use my usual kerf lining sized for ukes a...

I didn't put a rosette in this one because I thought it might clash with the rope binding, and the design brief was for a simple vintage vibe. As close as I could get while still bringing in my look. It certainly works Scale length is 22". Okay, so the instrument is smaller than I imagined, looks b...

Drop Dead Gorgeous! Love the body shape, the 14 fret join, giving the neck a long scale look. The makore is beautiful and the rope binding sets it all off. Not using a rosette the perfect minimalism in this context. And especially how it all works together, very, very nice. How did you make/install ...

........ You might also take a look at my CB #03, last in the line. This guitar is one of my earliest builds. It was okay at the time and is probably better than a 3, but I wanted to put it at the bottom of the list because of the oddly high mobility number. It was so high that I redid the measurem...

FFT Analyzer is REALLY Cool! Just scratching the surface so far but, looks great. Very easy to use. Just tapped out a 1917 00-18 Martin I'm working on. Got an average of taps over about 25 seconds (just keep tapping until the curve settles down). Peaks are about where I would expect them. I'm using ...

Okay, I get it, thanks.

Very nice guitar! I use the William Cumpiano joint and a 20mm diameter spot of hide glue between the extension and the top, as close to the end of the extension as possible for maximum leverage. This helps prevent any slippage of the bolts and insures no funny vibrations between the top and extensio...

For future reference. The chart type needs to be a SCATTER chart, not a LINE chart. Scatter chart allows values to be used for both the X and Y axis. Line allows values only on the Y axis, the X axis units are just the row number. Scatter charts can be format as points, connected points or "smooth l...

Thanks, that works. It is a bit different in Excel 2007, but same idea: Go to the DATA tab, GET EXTERNAL DATA, TEXT, FROM TEXT, (select file to import), DELIMITED, by SPACE.

Dumb question. How do you import VA text files to Excell? I can get the file to open in Excel and get each line of data in a separate row, but I get both the frequency and the amplitude in one column, so I can't plot them.

Are there commonly excepted frequency range definitions lows, mids, and highs as relates to an acoustic guitar?

Thanks Trevor, every bit of that makes sense and rings true.

Craig

One of my favorite parts of the Design book are the definitions of tonal qualities in section 3-30 and how construction affects these qualities. Can anyone elaborate on the qualities players call "dry" and "wet"? Some times the wet sound is said to have reverb and or sustain. To me, dry is a lack of...

Miguel,

Where did you buy the IPC signal generator?

Craig