a bass
This page shows steps along the road to getting my first doublebass made. When finished, in about winter of 2007, it will be my 10th instrument, with violins, a cello, and other odds and ends coming before. The bass has seen some changes along the way, though the core of the original plan remains; a small bass with a full voice, easily navigated throughout the range by any size player.

The strong turn of the ribs at the upper end is the most obvious accommodation of smaller players. Leaning in to reach the end of the fingerboard, or just to get the bow down near the bridge, the heel of the neck and upper back don't get in the way of the chest. Many other luthiers have sought to reduce the difficulty of playing past the upper ribs. Many bassists have suffered back and shoulder problems in straining to get around too-large or poorly designed instruments. Most solutions I've encountered seem well intentioned, but executed less than effectively, with the measurements relevant to the player remaining more or less within the normal, difficult range.

In designing this bass a balance was sought between volume and playability. A further problem has presented itself in recent times - airlines have place more stringent limits on both size and weight for luggage. Over the years I have repaired much of the damage wrought by airline baggage handlers, this in spite of very expensive and well designed bass trunks. The new rules have inspired lighter-than-ever trunk design, with less room for padding. Nice for carrying, not so great for preventing damage. Several luthiers have already responded, inventing ways of removing the neck of a bass and packing it alongside the body in a more compact trunk. Other luthiers, starting I think with Jim Ham, have introduced easily adjustable necks. The combination of these two advents has inspired me to incorporate both into this instrument.



Below is some early carving on the back. This is a rather deeply flamed piece of 'big leaf' maple from the Courtenay area on Vancouver Island. Difficult to carve and smooth, but when so much time goes into the instrument such expensive material is worthwhile.



Recent photographs of the back, taken in June of 2006. Smoothing of the inside is almost finished, so gluing to the ribs is not far off now. Another picture of the finished inner surface will appear here before that happens, a little later in the month. Then work on the belly will start. That's a piece from an ancient sitka spruce, which supported a logging bridge near Tofino for 25 years of rumbling, loaded trucks.





Getting close to tuned. Just a bit of smoothing and tinkering left to be done inside the back.



And now (June 12, 2006) the inside of the back is done. As many luthiers do even with violins I cleat the centre join, using thin spruce pieces, set with the grain at 45 degrees to the main. This angle allows for seasonal expansion and contraction across the grain without the glue coming loose. Most repair cleats should follow a similar principle, keeping the added mass very light and allowing movement - buzzing from larger cleats coming loose is all too common. The darker appearance of the wood is a thin wash of shellac which helps keep the surface cleaner over the years without interfering with the normal changes in moisture content.



The ribs now removed from the mould, the corner and end blocks shaped and linings trimmed, back is glued to the ribs... and the outside smoothed and lightly protected with shellac. Next to go in are the upper rib linings, again made of very fine grained yellow cedar, a wood I find excellent for linings and blocks. The button, at the top of the back, will not take its final shape until after the neck heel is glued in place. A few pictures of the finished back/rib assembly:







Most adjustable neck designs (if not all) cause the nut to rise or fall relative to the bridge, increasing or reducing pressure on the bridge. The design I've developed almost eliminates this by moving the neck heel along a radius from the nut. Of course fingerboards are dressed over time, nuts lowered, new boards and nuts put on eventually... and this means that one cannot truly isolate 100% of nut movement relative to the bridge. So what I've done is to take a point about midway in the nut's life, allowing that a tiny shift up or down will happen when adjusting between extremely high and low action.

Adjustment of the neck will be easy at full pitch, and re-tuning should be minimal, making it possible to adjust the action on stage. This introduces new possibilities to the artist, allowing change on a whim. Or the string height may stay as one prefers for years, adjusting slightly in compensation should the fingerboard need dressing or the climate change.

As with some other designs, this neck mechanism will also allow removal for safer flights in a trunk only a little larger than the body. With a capo to keep the strings on the fingerboard and a simple padded clamp to maintain the soundpost's position (or preferably removing the post for travel, as many baggage handlers are evil, destructive creatures), string tension may be taken down, then one bolt removed from the neck heel to allow the neck to be placed alongside the body in a separate compartment, along with bridge and tailpiece. Setup shouldn't take more than a few minutes, probably half a minute with practice and a string winder. I'll be posting a drawing of this mechanism once finalised, and show the actual mechanism once it's made.

Belly begins

At last I've got a break from repairs. The Bohemian bass I've been restoring is now assembled, though I need yet to build a new neck for it and graft on the scroll. There's been a little time to work on my own bass, and here's the result. I've removed more than half the spruce from the belly blank, cutting it almost to the final shape and carving the arching to about 1/4" thicker than it'll be when done. The inside is also roughly scooped out, to even out stresses while carving. I've found in the past that left flat, the inside plane can warp somewhat before it's carved, regardless of how many years the wood has been cured.


As is plain in these pictures, this sitka spruce has a rather pronounced flame in the grain. That is already making the work interesting, as the tools want to bite into the waves in the grain where with a plainer spruce they cut almost effortlessly smooth surfaces. Carving and scraping this wood smooth will be a challenge.

For those wondering about the extra-long cut out in the upper belly and the hole just beneath - that's part of my removable/adjustable neck mechanism. Some pictures will appear before much longer, showing how that looks in the upper block. For now, know that the hole is lined with a tapered 'bearing' of lignum vitae, something echoed in the upmost back, and all through the upper block to guide the main part of the adjustment mechanism. This is a tremendously tough wood often used for high-wear tasks, such as guiding the blades of large-scale bandsaw mills, or in the 19th century as linings for steamship propeller shafts. In addition to being very durable, this wood is more waxy than most, if not all woods, and is thus self-lubricating. Typically those steamship shaft bearings lasted as long as the propellers.


My boy Haru sometimes watches me work... though at just about 8 months old he doesn't have a lot of patience for luthiery. If you look behind the C bout - the belly here being carved out on the inside - he's the little face in the distance.

Now for the f-holes. Here's an uneven set of pictures of the process of cutting those; I don't use any tools besides a knife - the traditional sort, this one from Switzerland. One needs a very, very sharp blade for this, as spruce would rather split and flake off than cut with anything less. These pictures are all from the inside of the belly. Some makers mark from the outside. My preference is for the Italian method; marking from the inside then carving through to the outer surface.



And the almost-finished f-holes, this time from the outside - some fussy work left to be done, when it's quiet and I can focus well, but the basic shape is about right:


... and done




Here's the belly with bassbar fitted and tuned, ready to assemble with the rest of the body. That's now done. This week I'll be trimming the edges to final profile, cutting in the inlay (purfling), trimming that and the edge groove to a gentle hollow, then it's time to get busy finishing the neck.

The body was completed 'in the white' in mid-September. This past summer was a very full one for my workshop, and of course my son is running all over the place now and needs a lot of attention. So the bass has taken even longer, but the end is within sight. The neck carving is well underway. Here's a picture of the bass with a sealing coat of shellac. The only inlay on the bass is the belly purfling, done more for reasons of acoustics than ornament (I'm not a huge inlay fan), and is made of two layers of wenge wood sandwiching a thicker layer of yellow cedar. The hole in the upper belly will have a bushing glued into it once the varnishing is finished, through which will pass the axle which holds the neck in place and allows adjustment of string height.



Too many repairs... and of course my original work takes a back seat, when musicians have music to make but their instruments are broken. And it's been an awkward fall and early winter, so, much to do for me. Still, there has been the odd bit of time for carving. Here is the bass scroll, with the basic outlines established and needing a lot of smoothing before I move on to varnishing.



It's likely there will be something rather closer to finished posted here within the next couple of weeks. After that, I'll have to figure out where in the house my toddler son won't get at the bass while varnish is drying. The neck hardware, which will facilitate both removal of the neck for travel, and adjustments of string height, will soon be ready... or so the machinist tells me. gerard@luthier.ca