Acoustic 7-string experiment : "Will it hold?"

[luthierjules]

Hi all!

I've been taking the scenic route through life and had to put guitar building to the side for a while - you *might* remember the acoustic 8-string I built for Tosin Abasi back in 2012.

I've been working my arse off lately to finally be able to put food on the table with my building skills (designing models, estimating production prices, getting loans and whatnot...)

All the while, I took out parts that I started work on circa 2012 and decided I should have fun with them - no-one is waiting for this build, after all!

I'll delve into all the technical details and build steps as the time passes (I'm filming a video comparison of the sound qualities of my small acoustics in the coming week) but for now...

ALL HAIL THE NO GLUE/NO NAILS/NO SCREWS NECK JUNCTION!

You read that right - this is simply a wood on wood assembly and it uses no other mechanical attachment techniques/parts. Everything comes apart nicely and I'll even be able to make new bodies to see how they react/sound!

Also, here are top and back shots to get you started :

See you soon, guys!

 

[Anant Naag]

This is really something else ! If it works , it will be amazing, looking forward to video demos of these.

 

[BlackMastodon]

I would love to see more of this one. Looks really cool and interesting.

 

[rockskate4x]

HOLY HELL! looking forward to the technical breakdown of that neck joint concept! Also I'm very intrigued by having a floating tailpiece INSIDE THE FREAKING SOUND HOLE?!?!? WTF is this black magic?!?

 

[FIXXXER]

awesome idea!

 

[Serratus]

Looks really interesting - from the angles I'm assuming the tailpiece is the same piece of wood that joins the bottom of the neck?

 

[StevenC]

This is worth sharing, too.

 

[BlackMastodon]

Yep, it most certainly is.

 

[MoonJelly]

This reminds me of the old Mormon Tabernacle in Salt Lake City. When you tour there they make a point of telling you there aren't any traditional materials holding it together. Apparently they built it so the timbers were interlocking pieces, and wrapped the joints in wet rawhide. It's held up for like 100+ years.

Crazy what people come up with when they think outside the box

 

[luthierjules]

This reminds me of the old Mormon Tabernacle in Salt Lake City. When you tour there they make a point of telling you there aren't any traditional materials holding it together. Apparently they built it so the timbers were interlocking pieces, and wrapped the joints in wet rawhide. It's held up for like 100+ years.

Crazy what people come up with when they think outside the box

I had never heard of it! Now I'll have to add that to my bucket list of buildings/architectural elements that hold only with intricate woodwork!

From the top of my head, there is a church in Russia and the Loretto Chapel staircase in Santa Fe... don't get me started on Japan.

Back on topic, though!

I thought I should give you a few technical details of just what you are seeing.

So, you guessed it, it is an acoustic guitar and has seven strings.

I started work on it in November 2011 - it was supposed to be a quick, simple build of something I already had done, with the only exception that the body would be built out of that Western Red Cedar top/back/sides set I had bought another few years prior.

When I took it out 4 years later, I found the thicknessed top, back and bent sides, along with the neck, already dadoed for the neck junction and a glued but untrimmed headplate.

This meant a few constraints in design :

25-inch scale,
Small acoustic body,
A maximum heel thickness of 75mm.

From there, I decided to go a step further :

The body would be the deepest my tonewood would allow,
I could only use Western Red Cedar and Wenge (if necessary).
This would be my first step towards building a true acoustic guitar without the use of glue, nails, or screws.

...and of course I was very happy to realize there was enough material to make it with 7 strings!

More strings = More challenging... challenge.

I've shot a demonstration of the disassembly process and I plan on editing it tomorrow.

But right now, I'll go design a second bridge version!
Stay tuned!

 

[luthierjules]

Well! Video edit didn't happen. I can't decide if I should find a new cracked version of my software or work ever harder to afford it!

Anyways, I've done the design work on the second bridge version. The first version was very a very minimalist object that could have worked... But I'm getting too much torque where I thought I'd only have down pressure.

I've also decided on an opening shape and size, that's the white cutout -->

Just an opening to get a good look at the inner workings - I'm not quite ready to cut it open, as I want to inlay a slim black line all around it first.

Here's where I went with the bridge design :

I'm really expanding the wings towards the lower bout to compensate for the torquing effect the small bridge shows.

I love the sculptural look of the first iteration, but it didn't complement the rest of the guitar!

Two work days later, I've got this done :

It's so much like a moustache! But it'll counter the torque and spread the string tension more appropriately... It's about three times the area of the first one. 'Can't wait to string this thing up again to hear how different a bigger bridge will be!

 

[TedEH]

It really does look like a mustache, and the shape of the hole under it being kinda smile-shaped doesn't help. Or does help? Depends on how much you dig the "hey there's a face there!" look.

Edit:
New idea- embrace the it's-a-face thing, and make two "eyes" where the white cutout would be.

 

[Xk6m6m5X]

this is some sorcery if I've ever seen it...
really curious to see how this sounds

 

[timbryant99]

That is some mighty fine engineering. You, sir have some skills.

 

[luthierjules]

I've done the opening!

The strung-up bridge really looks too much like a mustache, especially with the white bone bridge pins acting as teeth...

But my main concern is that, while it does a better job at countering torque, it changes the sound too much. There is a noticeable drop in brightness (the first bridge had such a pure sound that it felt like the guitar didn't tint the strings' output) and I feel like it's a bit dampened...

In other words : there will be a version 3!

Next in line : decorate the inner structure like crazy as well as do the bindings! By hand, of course... I doubt the soft sides will like to be pressed on with a router bearing!

 

[Hollowway]

I think you're really going to put yourself on the map with these. They're beautiful, super cool, and solid work. I wouldn't be surprised if you're spoken in the same breath as Michael Spalt, Rick Toone, Ola Strandberg, etc. Very innovative!

 

[neun Arme]

Man I'm impatient to see the end result.