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Hello -

I'm looking for some help on carving steel-string acoustic guitar necks. I have read online a number of references to an approach that involves carving facets. Pablo Requena has a video and Liutaio Mottola has a page on his site. I had two questions:

1) Do people have their own variations or examples of other online resources on this technique that they found useful?

2) How do calculate the measurements of where to cut your facets for a neck blank thickness?

For the second question, I have seen videos/resources that provide a single set of measurements, but I have not found an explanation on how to adjust the dimensions if you choose a different thickness or taper for your neck.

Thanks!

1 This presentation includes a section on laying out facets - https://seattleluthiers.org/wp-content/uploads/2020/01/Neck-Carving-2.pdf

2 calculating: First step is to taper the neck and taper the thickness of the the neck to within a sanding difference. Then draw out full size cross sections of the uncarved but tapered and thicknessed neck at the first and the 9th fret (stay off the heel transition). Then draw the desired profiles into the cross sections. You can draw your own, use a template, use a pattern tool to copy a neck you like ...

For the primary facets draw a line tangent to the profile taking off as much of the excess wood as possible. Measure from the points where the facet line crosses the cross section lines; from the center of the cross section and from the fretboard face or the fretboard, depending on the where you are in the build, symmetrically transfer those points to the neck to the corresponding locations at the first and 9th fret location. Draw four lines connecting and extending past the points from the measurements. These are the primary facets. I leave it at that for a classical neck, it is a relatively flat curve. But if you have a steel string neck that you want to nail the curve, like a V neck, then repeat the above procedure to cut off the 4 newly created corners of the primary facets. That is draw lines tangent to the profile that intersect with the new cross section with the primary facets. I have seen tutorials for tertiary facets but have never made them.

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http://www.Harvestmoonguitars.com

While I don't do a Spanish heel, I shape the shaft of the neck in the same fashion as John posted.

In short I,
1. I usually make the fingerboard first tapering the side per my plan. I lay the fingerboard on the neck shaft being careful to get it straight on the centerline and the end of the board firmly against the nut. Then I clamp it in that position and drill three small holes for locating pins, (the small ones LMI has). Two in the slot for the 13th fret and one in the slot for the 1st fret. Then I put the pins in, drew lines on each side of the fingerboard and remove it. As a double check, I measure from the lines to the centerline of the neck at the nut and Body joint. The distance should be the same on each side of the centerline.

2. I put a mark on the side of the fingerboard at the 1st and 10th fret representing how thick I want the neck without the fingerboard (You should be able to get that from your plan)

3. Make a tapper board that once stuck to the top you will be able to use a Saftey Plane attachment for your drill press. (for me it tapers about 1/8" between the 1st and 10th fret) Plane Just from the 1st fret to the 10th. Don't go too far! You will now have the back of the neck shaft shaped just the way you want it. (IT SHOULD BE VERY FLAT)

4. I then cut just outside the two lines I drew on the top of the neck shaft leaving extra wood. I finish those up after the FB is glued down.

5 Now is the time to lay out the facets. Do it like it shows on Johns's attachment. Basically draw a profile of the neck at the 1st and 10th frets on paper, giving the shaft the shape you want. Then draw a line across the outside of the arc (as it shows in John's attachment. Then Transfer to the neck shaft at the 1st and 10th frets and draw a line on the bottom and side the same place as shown on your 1st and 10th fret drawings. That is the facet you shave off. I use a rasp for that

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Joe Beaver
Maker of Sawdust

Pretty much exactly as I was taught and still do it. Can’t imagine attempting a specific neck profile without doing this.


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One quirk I add to the approach is to take measurements in cm, but scale the drawing so that 1 inch = 1 cm. Much easier to work with an enlarged profile on paper.


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https://www.youtube.com/watch?v=1m7gIHZryes&t=731s

This is a classical builder but he explains it VERY well I think

I shape the profile at 1 and 10 marking out facets using pretty much the measuring technique shown in the Seattle luthiers article.

Otherwise my technique for making necks is a lot different from the article.

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It's not what you don't know that hurts you, it's what you do know that's wrong.