Cavaquinho Neck Construction

June 17, 2011

It’s now time to make the neck.  I have used mahogany for the necks of all of the cavaquinhos I have made so far.  Mahogany is a great material for instrument necks.  It is strong and light weight, easy to carve, and stable in the face of changing climates.  This last point is of greatest importance because we want the instrument to remain playable on dry days as well as wet ones.  If the neck were to expand and contract markedly every time the weather changed, there would be endless problems with fret buzzes and string action, and that would make for an unreliable instrument.

The first operation is laminating the heel block onto the neck.

Next, I mark the outline of the neck and cut it on the bandsaw.

I now turn my attention to the end of the neck that will join the body. 

There are many acceptable methods of joining the neck to the body.  A dovetail joint, which is common in guitar construction, could be used.  Alternatively, the neck could be pinned or bolted to the body.   I prefer to use a mortise and tennon joint that will later be reinforced with dowels.  Each method of  joining these parts has its strengths and drawbacks.  I have used the mortise and tennon approach on most of the instruments I have made over the past 25 years and have gotten very consistent results.  The big drawback to this approach is that it is very difficult to align everything properly so that the neck is at the right angle to the body and that the centerline of the neck goes straight down the middle of the top.  The advantage of this approach is that once the joint is assembled it never moves and it has no gaps, so no string energy is lost in the neck-to-body joint.

I use a table saw and bandsaw to make the tennon at the end of the neck.  I didn’t think to take any pictures while making those cuts, but here is the roughed out tennon.

I will use rasps and files to make adjustments to this side of the joint, but before I do that, I need to cut the mortise out of the headblock on the body, which I do with a handsaw and chisel.

 

Next I check the alignment and make any necessary adjustments on the tennon or the gluing surface of the neck’s heel.

That end of the neck is complete for now, so it’s time to make the peghead.  The wood being used isn’t wide enough to make the peghead shape that I want, so I glue some mahogany wings to extend the width of the head.

After the glue dries, I scrape the extensions flush to the rest of the head then glue on the peghead veneer.  For this instrument I will use a koa veneer because of the koa body.  After the veneer is on, the profile of the head is cut on the bandsaw.

Now the holes are drilled for the tuners.

The last operation I perform before gluing the neck to the body is shaping the heel.  It is much easier to do this before the pieces are attached.  I use rasps, scrapers and eventually sandpaper to shape the heel.

 

After the heel is shaped the neck can be glued to the body.  The shaft of the neck is kept square for now because it will be easier to attach the fretboard if there is a flat surface for the clamps.

After the neck is glued, I drill two holes through the edges of the mortise and tennon.  The holes are half in the mortise and half in the tennon.  They run almost the full depth of the joint and are exactly the right diameter to hold two pieces of oak dowel.  These dowels will be glued into the holes and they act as an additional means of anchoring the neck joint.

 

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2 Responses to “Cavaquinho Neck Construction”

  1. Thanks, very helpful.

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