welcome 2020

I’m making yet another attempt at trying to bring this website back to life. Will start by posting some pictures of the new guitar I’ve been building since early 2018.

I’ve set the publication dates to when I actually did the work, so if you prefer to read this chronologically you might wanna start down at the bottom of this page, or use the individual post links on the left.

More shaping

In 2019 I didn’t make much progress with the guitar at all, mostly because my day job kept me busy for much longer than planned. On top of that I moved both our home and my shop (into one location actually).

So it took until April 2020 that I sprung the CNC machine back to life and continued giving the guitar further shape. Here you can see it working on the neck-body joint:

To properly cut the neck contour I had to go beyond the 2.5D approach and go full 3D. In a move to use more open-source software I opted for FreeCAD (also switch to kicad for PCB design recently).

3D tools have a much steeper learning curve of course, so it took me a while to come up with this first design:

Here’s that section after some manual sanding:

While I started applying this 3D approach to the body as well, I realized that it was way too much work just to give all the edges a 5mm radius, so from there on out I went back to good old files and sand paper.

Here’s how that turned out for a section of the back:

I also applied the manual approach to shape the head-stock. Here’s a picture of its back:

With strings!

body shape

As you can see from my previous posts, the CNC machine was used for much more than originally intended. So as a next step it came naturally to also apply it to fine-tuning the body shape.

As CamBam isn’t really the best tool to draw Bezier curves, I resorted to good old Adobe Illustrator to draw the outline:

Although not trivial, this could then be exported as DXF and then imported into CamBam to base the toolpath on.

I had to order an extra long end mill tool to cut all the way down from 40mm height to ground (took a while too…)

This slope actually done manually:

The next design decision was not what I had planned (although one guitar maker had warned me when I bought the ziricote). The problem was that this slab of wood was darn heavy:

More than 50% above a standard Strat body:

So as I needed a lot of room for electronics anyway, I decided to cut pockets everywhere, turning this axe into a semi-acoustic (or maybe quarter-)

Much better now :)

headstock

As you might have guessed from the previous posts and pictures, the amount of wood I left for the headstock would not allow for the traditional placements of the tuners. In other words, it’s a so-called head-less design (technically there’s actually still a head – it’s just much shorter)

So this approach calls for two components:
First, you need tuning machines down at the bridge. This is relatively easy to source – in this case I went for ABM bridges with Graphtec pickups. Thanks to Peter Borowski from ABM, Berlin for helping with this.

The second part are the clamps to hold down the strings at the headstock. While there are purchase options for these too, most do not come as single pieces but as a block for all 6 strings. Which, again, doesn’t work with the wide string spacing I prefer.

So I decided to come up with my own design, where the plan was to work as much as possible with the wood itself, rather than attaching a full-metal solution.

Of course metal is needed in some parts, otherwise the wood would wear down over the years. So I designed an inlay where the string runs over a tiny metal bridge, with slots at each side for the metal clamp.

I milled this inlay out of a piece of brass that I had still lying around. This was the first time I used the CNC for cutting metal, so I was a bit nervous if it could do the job, but things turned out nicely without breaking anything:

And the pocket to match:

This was then extended with deeper holes for the clamps:

And holes from the back for screws to hold them down:

Tada, first string clamped down:

neck joint

I decided to practice the neck joint with a piece of maple I had left over, because I was afraid to get it wrong and then not being able to undo the damage.

I went for a slotted design to stabilise the alignment. Used three M6 Rampa wood screw inserts.

This seemed to work fine, so I applied it to the Ziricote body…

…as well as the neck:

And here’s neck and body joined for the first time:

neck

Here’s the neck with the truss-rod already in place. You can also see the fretboard behind it – I didn’t cut the slits for the frets myself, although with the CNC machine that would be possible of course. But back then when I ordered it, that wasn’t the plan

Mating fretboard and neck:

Not the most professional clamping job, but it worked out fine.

Milling the sides for the correct width:

The completed rough cut of the neck:

The headstock is still rather blocky, as I wasn’t sure what shape it should have, so I left more material on in order to have options.

Also note the round shape at the end where it meets the body. It follows the curve of the sound hole of a classical guitar. More on the neck-body joint in the next post

Strophonion

The Strophonion is a sensor controller devised by Alex Nowitz for manipulating his voice in live-electronic contexts. It was initially developed at STEIM, using their expertise in hardware design as well as their software offerings, in particular LiSa and Junxion.

I got involved starting in 2014, when I helped building the next revision of this controller:

stroph

The electronics are largely the same as in the previous version, however we added an option to connect the controllers thru a cable in case the wireless system breaks down. The basestation though is a completeley new design.

Most notable are the 3D-printed shells which were designed and built by chihauccisoilconte. Here’s the new and old designs side by side:

stroph-compare

In the following years, Alex and I embarked on a long journey to also update the other half of the instrument design, i.e. the software. The aim was to implement the signal processing in a more open, flexible, and expandable environment, so the complete functionality was transfered to MaxMSP. This process take longer than expected, but in late 2018 Alex was able to present the new version of the Strophonion in a concert as part of his PhD project.

 

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