CNC

I bought this initially to
a) do quick PCB prototypes,
b) cut irregular holes into enclosures, and
c) for some very specific guitar jobs.

As it turned out I’ve used it progressively more for c), a little for b), and not at all yet for a).

The main guitar job I had in mind back then was to precisely plane the body and neck areas where they will be joined, as that’s something hard to get right with just manual tools.
But after playing more and more with this machine, I found myself applying it to many other tasks, while also improving my CAD/CAM skills.

The first step was to test the machine with the manual controls, so I made some exploratory cuts in regions that would be cut away anyway:

Next, I wrote a number of scripts in gcmc, i.e. one step above bare-bones g-code. This is used to cut a narrow trapezoid from the bridge to the end of the body to delineate the area where the strings would go.

Then, after this turned out nicely, I wanted to try more advanced stuff. So I bought a simple CAM application (CamBam) that would allow me to design basic 2D shapes that would then be milled to a certain depth (what is commonly called a 2.5D approach).

I applied this first to pockets for the bridge elements to ensure that they are perfectly aligned.

The software can calculate a tool path and then export this to g-code, which can be read by the CNC controller, in this case Mach3.

Here’s the machine in action:

And here the result:

wood sourcing

A lot can be said (and fabulated) about the tonal qualities of the various types of wood used in guitar making, alas, having not much personal experience in this field, I admittedly based my choice largely on visual qualities.

In particular I came across this neck piece of Ziricote, a tree I had never heard of before, but immediately liked due to its intricate markings:

As I prefer single-type wood guitars (save for the fretboard) I then faced the much harder task of finding a large enough Ziricote piece for the body. Most dealers said this was not possible, but after much back and forth Nebelheim Tonewood procured a plank that seemed promising (thanks much to Manuel Wemmer for helping with this):

Note how the dark core is surrounded by lighter wood.

Of course this wasn’t wide enough for a one-piece body, and even a two-piece didn’t pan out because I had to work around a crack. So I ended up with this cutting plan:

Put together like this (Photoshop simulation):

With an overlay of an early design sketch:

I then took this to a local shop in Berlin to do the actual cut and paste. Thanks much to Guitardoc and Anthony Schneider in particular for the help!

I forgot to take a picture of the raw assembled block, so here’s one at a later stage where the upper curve has already been cut out:

More on the machine in the background in the next post

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