Australian/New Zealand Luthiers Forum

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...

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.

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...

With only 4 W RMS power, I don't think that's enough (c.f. 30 W RMS on the unit I built). You can probably get away with 15 W RMS. Modifying this unit for more power would require a new power supply and power amp module, or putting the output through a cheap stereo amp (e.g. like this or this).

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...

Nice work! Definitely one for "The Book" gallery!

The guy who inspired your rosette was "Tricky Fish".

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 ...

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...

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 ...

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...

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...

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?

Check out that peak at ~440Hz. That's likely your problem...

In the 2nd Edition, Section 22.3.4 shows an example of how to fix this sort of problem on the 2nd partial (not in the 1st Edition). Also likley in the Modal Tuning Course notes.

I haven't used them either, but I would drill full depth at 6mm then open out for the collar with a metric step drill that has (at least) 6, 8 and 10mm steps. Picking up the original 6mm bore with the 6mm step should keep everything concentric. Best done with a pillar drill to keep the bores square ...

You may find this interesting:

https://www.classicalguitardelcamp.com/ ... 3#p1543313

I measured 9 top plates today and calculated targeted thicknesses for 343 mm wide 0 guitars. Adirondack, Engelmann, Lutz and Sitka. I look a random 10% stiffness reduction considering the top width. If you're using the formulae in the books for the elastic constants, measuring them correctly and ap...

If you're looking for a gap filling glue, avoid Titebond. The thinner the Titebond glue line, the stronger it is. I would also avoid liquid epoxies, which is what G/Flex appears to be. You need the glue to stay where you put it. So I would suggest using Techniqlue (an epoxy), which is thixotropic, s...

nkforster wrote: ↑

Thu Jul 29, 2021 6:01 pm

Trevor may have tested this scientifically, but I've not.

No, I haven't done any objective tests.

Page 20-8 in the Build book. Make a convex sanding form by either laminating veneers into the top dish that you used (then dress any spring-back by sanding in the dish) or just sand a block from scratch in the dish. I start with 80 grit and it never takes very long (no more than 5 minutes total) to ...

The UK is quite a low proportion of sales, which was a bit surprising as I know there is a lot of interest there. I think VAT and import duties really loaded up the price. The USA is a big market (no import tax/duties) and also Canada, which does have import taxes. There has been good interest acros...

1.5mm as per the second edition. Apologies for the typo that got through in the 1st edition.

When you've had a website up and running for a dozen or so years it can get quite big. I hadn't realised how much stuff I had there until I got a message from my hosting service saying they were going to switch off the content editor. That was about 6 months ago, so my website has been frozen in tim...

Nice guitar, Martin. Regarding the changing frequency responses, your early responses without the neck mean you couldn't have had strings on, and you may not have had saddle and bridge pins in. Just adding the mass of the strings can make quite a difference which people often put down to loading the...

I haven't found much info in the book regarding truss rod extension pocket for BO. :o !! Section 18.9.1 I wonder about where to place the adjuster nut Fig 18-7 Also when the fingerboard is finally glued down, how to stop glue entering the rod channel. Section 18.6, esp. 2 lines up from the bottom o...

This may not be the only problem, but certainly looks like one of them... Looking at the thickness of the residual glue on the tail side of the detached bridge, that glue line looks way too thick, to the extent that the the joint looks like it wasn't properly closed. There could be numerous reasons ...