The Numinous Atheist

"I took the lamp and, leaving the zone of everyday occupations and relationships where everything seems clear, I went down into my inmost self, to the deep abyss whence I feel dimly that my power of action emanates. But as I moved further and further away from the conventional certainties by which social life is superficially illuminated, I became aware that I was losing contact with myself. At each step of the descent a new person was disclosed within me of whose name I was no longer sure, and who no longer obeyed me. And when I had to stop my exploration because the path faded from beneath my steps, I found a bottomless abyss at my feet, and out of it came — arising I know not from where — the current which I dare to call my life."

-- Pierre Tielhard de Ghardin, The Divine Milieu, Part Two, 2. The Passivities of Growth and the Two Hands of God, pg. 77

I recently reread Bless Me, Ultima by Rudolfo Anaya.  It's even more wondrous and amazing than I remember from when it was a middle-school reading assignment.  The main character, Antonio, a seven-year-old boy growing up in southeast New Mexico during World War II, struggles to reconcile the divergent ways of understanding the world that are pressed on him by his elders with those he discovers on his own.  Mystical, magical, horrifying, and inspiring, his experiences are grist for the mill of his young mind sorting the paradoxes of being human.  The story resonates with me because Antonio's confusion and drive to understand his world describe my own lifelong experience of wonder, fear, and hunger for certainty.  

Some of my earliest memories of my childhood are of moments of what I now call the numinous:  standing on the brick porch entry of my family's Upper Michigan Air Force Base quadruplex apartment -- as mundane a place as any -- and having an intense experience of being ready to die, expecting to be "taken up," even spreading my arms and looking skyward toward ascension.  I was probably four.  At age 10, playing in a stream in the North Carolina backyard of my best friend Beth, I remember a certainty that there was something magical about the place, that we were part of and witness to something bigger than us, something immense and incomprehensible.  As a young man watching the sunrise and writing in my journal as I dangled my legs off the edge of a lava flow atop Albuquerque's West Mesa, I surprised a wandering coyote who didn't see me sitting there until he was just a few dozen yards away; the moments we gazed at each other before he trotted off felt both matter-of-fact and transcendent, a magical space that would endure in my mind for the rest of my life, yet passed as quickly as a sandgrain meteor.  These, for me, are incontrovertible experiences of the numinous.  

Today, I hunger for that numinosity as much as I did as a child and youth, but an entire other self has developed, too.  My father had no room for mysticism, disdaining anything that smacked of magic or even the impractical, so I was taught early on that such ideas were for fools and, thus, if I wished to be anything other than a fool, I needed to eject these notions at their first showing.  Was it provable?  Demonstrable?  Repeatable?  If so, it might have merit; beyond that, it belonged in the trash bin of the gullible.  My father was not harsh, but he had a way of conveying disappointment that made clear my childhood fascination with ESP and spells and hexes was worthy of shame.  The most devastating blow to my obsession came in sixth grade, when a group of classmates conspired to convince me that one of them was brilliantly clairvoyant and the teacher, rather than interrupt their cruel joke and admonish the conspirators, simply rolled her eyes at me and let them play it out until I was utterly humiliated.  After that, I basically exiled my numinous and mystical self.  

Instead, I came to worship the empirical.  Without knowing it for what it was at the time, I took up the skeptics' great question:  how can we know what we know?  What can we learn with our imperfect and incomplete senses?  How can we augment our senses or account for their imperfections?  Given that, even with such augmentations or accounting, we nonetheless process all information with limited minds, how can we know if there is even anything "out there?"  Am I the only being in the world, the rest an illusion (the solipsist's conclusion)?  This makes no intuitive sense, but then can I trust my intuition?  

After years of such wandering, rejecting the numinous yet being unsatisfied with the empirical alone, my undergraduate studies in epistemology and skepticism helped me find a happy, workable (while still imperfect) solution:  there is a world "out there" and, although we cannot know it perfectly, we can know enough about it to operate effectively in it.  Indeed, there are ways that we can work to make our knowledge ever less imperfect and these ways are called science.  

Today, I am a trained scientist, an empiricist, materialist, and practical skeptic.  I do not believe in the existence of god(s), the spirit or soul, nor, by extension, ghosts (spirits with no body) or zombies (bodies with no spirits) and their ilk.  At the same time, it feels wrong to invalidate and shame others who do believe.  Moreover, how do I reconcile my own experiences of the numinous?  Again, my father, unwittingly perhaps, pointed me in a useful direction:  wonder.  As an engineer and a true geek's geek, my father had that childlike, "gee-whiz" excitement when it came to the sciences he studied and the gadgets he built.  His commitment to the empirical was not absent of wonder and, indeed, wonder drove all of his passions, whether flying airplanes, studying advanced mathematics, building race cars or personal computers (before they were a thing), or touring the Great Parks of North America in a 1961 Greyhound bus he converted himself.  Perhaps wonder is sibling to the numinous.  

Even after being shamed and argued into rejecting the mystical, I never stopped having mystical experiences.  In my late 20s, after I broke up with a woman I thought was my One Great Chance at True Love, I spent a (completely sober) day and night filled with music and visions, following a call that ultimately led me crashing nude into midnight ocean waves on an empty city beach, feeling that an old skin was being beaten off of me.  In my late 30s, following the birth of my daughter, I went through a period of introspection and transformation that changed the course of my life, a deep dive into religion and art that ultimately led me to becoming a psychologist.  Change and clarity arising from I know not where have punctuated my life, leaving me convinced in the moment that I am a mere vessel or conduit for some greater power.  

In studying the human brain, I've come to understand that such incongruous experiences have their origins in the fact that the conscious mind is but the thinnest of veneers over the vastness of the psyche:  the consciousness that the brain produces is but a fraction of its output and its greatest products appear to be outside conscious reach -- perception, identity, meaning, even decision-making.  Thus, what some people call God or spirit -- the experiences I call numinous -- likely, in my empirical cosmology, arise from these deep workings of the mind and brain.  Yet, that explanation of their origin does not make them less wondrous -- or numinous.  

Now as ever, I strive to stay in touch with the numinous in my life.  The breathtaking spectacle of the sugar maple in my autumnal backyard, the shivering insight that melts from a patient's face down through their body, the bottomless space beyond the planets on a moonless night, the derealized moment when a tarot card reveals its meaning, the joy and wonder in the eyes of loved ones, the sudden Knowing of a personal Truth, all these are part of it.  The numinous is a human birthright, from wherever it springs.  Christianity, Judaism, Islam, Buddhism, Taoism, Paganism, Wicca, spirituality, science, all of these are ways of explaining the how of our experience, but the what cannot be denied.  

I honor your numinosity as I honor my own and I wish for all humans to be in touch with theirs, however that may occur.  

Rotola: The Bridges and the Stand

 In my last post about the rotola focusing on the construction of the nut, I included an overview of basic string instrument construction; for review:  

In this post, I'll focus first on the other end of the resonating part of the string, the bridge, and then on something unique to the rotola, the stand on which the instrument rotates.  

The rotola has 16 strings and each string has its own bridge.  Here's a drawing of the bridges' front and side views:

They are not big, about 18mm high and maybe 6mm thick at the base and ~1.5mm at the top.  I decided to make them out of purpleheart, of which I have a large chunk.  I like the wood a lot, although I don't often use it, as it's really difficult to work with due to its extreme hardness and density; however, those same properties make it good for this application.  Additionally, while I have some hard maple, which is a more typical wood for string instrument bridges (particularly the violin and viol families), I wanted something that would contrast visually with the spruce of the soundboards.  

Fabricating these would be a challenge:  I needed to make at least 16 of them (spares would be nice, too) and they needed to be uniform and precise (note the curved base that fits exactly on the soundboard), plus, being small, they are hard to hang onto while working.  After much thought, I figured a way to make them from a long strip as a starting blank.  I could plane the strip at an angle along one face, then, supporting the planed side to keep the centerline correct, plane the same angle along the other face.  Next, I would mark out the width of the bases using a pair of dividers and then sand the correct radius between those marks.  Finally, I could saw out the rough triangles and clean up the sides using sandpaper on glass and file the notches for each bridge's string.  This more or less went to plan, although I mades some mistakes while working it out and had to start over.  

Here are some views of the process:

The purpleheart blank after it was cut, milled, and planed to size as precisely as I could make it.  

Two views of the jig I built to run the blank through the surface planer:  

For the second run (which I neglected to photograph), I had a shim with same angle as the cut, so the second side would be held at the same angle as the first going through the planer.  (For my first attempt at this, I used a hand plane and struggled to get the angles correct and consistent; the above success was due to having purchased a surface planer.) 

This is the setup I used to cut the radii into what would become the bases of the bridges.  The wheel is cut from 1 1/2" MDF (actually two 3/4" pieces glued together, leftovers from another project); I cut it initially on the bandsaw and then rounded it against the oscillating belt sander by rotating it on a fixed dowel inserted into the center hole.  I then stuck 120 grit sandpaper to the edge using spray adhesive.  I was able to raise the work surface by cutting some 1/8" plywood to fit around the disk and clamping it to the drill press table; this prevented leaving a ledge of unsanded wood where the bridge blank might slip under the spinning disk.  The setup worked fairly well, being only a bit off of parallel to the table.  

Here you can see the scallops made with the sanding disk.  

Next step was to cut the bridges out, which I did using this jig (left) and a pull saw.  The vertical piece of the jig had a magnet embedded in it to keep the saw at the correct angles (defining the side of the trapezoid and keeping the edge square to the centerline).  This also worked fairly well and you can see some of the cut bridges in the cup at center, but, unfortunately, I seem to have neglected to get any close-up pix of the finished bridges; you'll see later how they fit onto the instrument.  

Next, I went to work on the stand for the instrument.  As it is intended to be played by a single person, cranking with one hand and bowing with the other, it needs to be supported at the axle ends so that the pins and bridges have clearance from the stand, but not so high as to raise the business side -- the strings rotating across the top -- inconveniently high.  The simplest design would be some basic yokes at the ends and a plain platform spanning between them; however, I wanted the stand to be a part of the presentation and be attractive enough to compliment the instrument.  

I started out by hand milling down a large piece of fairly warped but beautifully figured walnut given to me by a friend.  This was before getting either a jointer or a surface planer and became an exercise in confronting my amateurism, ending with turning most of a 6/4 piece of wood into sawdust or shavings; you can see the resulting piece in the middle of the bench, below -- it's less than 5/8" thick.  

The two square pieces with holes drilled in the center will be the end supports.  These were resawn from 3/4" pre-milled stock and so was much less disastrous.  

I spent quite a bit of time experimenting with different designs before settling on these profiles.  

After routing roundovers on the stand's components, I rabbet-jointed them together with glue; I did not want any hardware or dowels showing.  Next, I cut two knees for each end to add strength to the joints.  

Here you can see the knees being glued in place.  

In the end, the joints were plenty strong enough and I am very pleased with the overall appearance of the stand.  

Notice that the left-hand end of the stand, for the nut-end of the rotola and over which the bow will rest, has a longer squared end than the right (below).  This is because, at the time, I was still considering anchoring the bow at the left end and making a hinge so that the bow -- and presumably some weight -- could rest on the string and not require a player to manipulate it; the hinge would connect to the stand somewhere along that straight edge.  I have since changed my mind on that bow design, but I still like the asymmetry.  

The right-hand end of the stand.  

Again, I neglected to photograph the finishing process, but the results will be seen in later posts when the instrument is fully assembled; it looks pretty good.  

Next post I will cover the fabrication of the crank and the bow -- and then it will be done!

Rotola: The Nut

So far, I've talked about the rotola's construction fairly idiosyncratically, discussing what I'm doing as I'm doing it, but, apart from sharing pix of the original design, I haven't contextualized what I've done within the instrument overall or within the principles of chordophones generally.  We're coming to a point where a little of that background might be useful.  

On most stringed instruments, the string runs between two anchor points that keep the string in tension and across two contact points that define the length of the resonating section of string.  Thus:

Note that the  contact points are by definition between the anchor points.  This is true of all stringed instruments in one way or another, with variations in how their different jobs get done.  

There can be some further specialization, however, within these jobs.  One of the anchor points will usually have a mechanism for adjusting the string tension and one of the contact points usually has the additional purpose of transferring the vibrations of the string to a resonating body.  We name these different points according to their roles:  

The anchor point responsible for adjusting the string tension may be called a tuner, tuning pin, tuning peg, etc.  The anchor point that holds down the other end of the string, usually immobile, is sometimes called an end pin (in some instruments, instead of a pin, there is a hole into which a thickened part of the string catches).  The contact point that transfers string vibrations to the resonating body is usually called the bridge and the contact point that holds the other end steady is the nut.  Most string instruments have some version of all of these, although sometimes a piece might do more than one job, as in the bowed psaltery, in which the end pin also serves as a nut.  The most important job of the nut is to provide a solid point against which the string can vibrate, i.e., by being a rigid surface, it inhibits the string's movement as minimally as possible.  (This property is necessary for the bridge, too, but I would say it's first job is to transfer sound to the body.)

Whether the bridge and the end pin are located at the same end of the instrument or not is usually dictated by the structure of the instrument and how it gets played.  In violin, viol, and guitar family instruments, for example, the tuners and the nut are usually near each other and the bridge and end pins/holes are together at the other end.  But it can be the other way around, which is the case for the rotola:

More precisely, per my initial design:

So, as you can tell from both the end of the previous post as well as the title of this one, I'll be talking here about the design and fabrication of the nut.  

Despite the octagonal cross-section seen in the above initial design, as discussed elsewhere, I decided as I began to build the instrument to aim for a cylindrical shape instead; thus, the nut will need to be circular as well.  However, the grain of the wood comprising the nut, in this case walnut, will need to run perpendicular to the strings it supports.  As no trees grow with the grain in a circle (growth rings don't count, as the fibers are still longitudinal), the nut will have to be assembled similarly to the pinblock -- what I came affectionately to call pizza slices, as I struggled to get yet again perfect 22.5° cuts.  Using a bandsaw, this is tricky:

The one on the left, you see the cuts are too shallow and on the right, too steep.  These are just two of my many attempts to get the jig set right using scrap wood.  In the end, I finally got one close enough:

You can still see some small gaps, artifacts of having to use the oscillating belt sander to get the angles just right, but I had wasted a good deal of wood already, and my tools and my skill with them were not going to let me get more precise than this anyway, so I glued it up:

Next step was to round it off, which entailed first circularizing the center hole and then using that as a pivot to do the same with the circumference.  

I spent quite a bit of time laying out and fashioning a jig that would allow me to center and hold the nut on the drill press; unfortunately, I neglected to capture that work, but here is a shot of the completed center hole with the nut correctly placed on the jig:

The slots in the frame allow the jig to be bolted to the drill press table; the alignment marks have complements on the table and those on the nut then line up with the jig.  Using this system, I was able to place the 3/4" blade bit precisely in the center of the inner octagon and make a perfect pivot hole.  It's amazing what good marking up can yield.  

Next was to make a jig for circularizing the outside of the octagon.  Using a scrap bit from a practice axle, I set up a way to hold the nut firmly in place on the table of the oscillating belt sander sufficiently precisely at the radius I wanted:

The long edge allowed me to keep the whole thing square, which was the key to controlling the radius (from the center pin to the sander face).  Thus:

I was very pleased with the end result:

In working with the walnut thus far (this was the first part of the rotola that used walnut), I began to realize that, while it is a relatively hard wood, it's not as dense as a nut really needs to be.  My original plan was that the strings would be supported directly by the nut, draping across its edge (as you can see in the third figure, the one labeling the various string supports), but I began to think that the walnut was just soft enough that it could have a dampening effect.  Given that the rotola's strings should be highly resonant in order to create the sound I aurelize, this was a risk I was unwilling to take.  

I played with several ideas for solutions, including remaking the nut with ebony or maple on its edges or even fashioning a new one out of those materials.  However, in the end, I took inspiration from the bowed psaltery, which has a slim bar of brass on its bridge.  Brass is hard enough to support the steel strings rigidly, malleable enough to work with in a woodshop, and looks good, too.  

Having procured some 1/8" brass rod from my local Big Box Home Store, the next step was to mount it onto the nut's edge, most simply by cutting a groove into it.  As with much of this project -- indeed lutherie in general -- this would require making a jig.  Fortunately, I needed only modify the one I'd made to circularize the nut, standing it on its edge and mounting it to the router table.  After some trial-and-error, I came up with this:

A v-bit in the router could be raised (via the black and yellow handled adjustment shaft on the left) into the edge of the nut, then the nut could be rotated on its axle, creating a fairly straight and even groove.  Both the axle and the router bit are seen better from the below angle (seen from the other side of the fence): 

I was pretty happy with the result; it's not perfect, but more than good enough for a proof-of-concept:

Next, I wanted to taper the outside edge, giving a smoother transition for the strings on the end pin side (outside) of the nut.  After more trial-and-error, I came up with a setup that would allow some consistency:  

The rounded nut (here a practice scrap) rests on the bench, with a bench dog through its center hole (serendipitously the same size as the axle), then a guide keeps the plane at the same distance -- and thus the same angle -- relative to the nut; counting strokes and rotating the nut the same number of degrees as I worked my way around helped me rough in a taper:

These large facets (seen below in the nut itself) were smoothed by making smaller facets in between:

These were then blended and rounded over with sandpaper.  

Next step was bending the brass rod.  I expected that, in order to get a good fit, the rod should be wrapped around a cylinder that was somewhat smaller in radius than that nut itself, to account for springback.  I made a form, which turned out to be too large, then a smaller one -- 

-- which was still too large.  Rather than continue to make circles out of wood, I decided to look for ready-made cylinders, like cans of finish:

-- which turned out to be just right.  

I got the brass rod to a rough fit, cut it, and then taped it to the nut to see a) how well it would sit in the groove on the edge of the nut and b) how much pressure from the strings would be required to get it to sit straight and evenly in the groove.  

You can see some of the wobbliness, especially in the lower of these pix.  Masking tape was capable of holding the brass down fairly strongly, but I'm unsure if the strings (even considering that there are 16 of them) will generate enough power to keep it firmly in its slot.  That said, I decided those were problems to resolve another time and I needed to keep going to finish the nut.  

The last fabrication operation with the nut would be drilling the holes for the end pins.  This would require some accurate marking out:

Here, you can see I started by marking out the radii at 1/16th circumference (or 22.5°) arcs.  I'm using the seams between pizza slices as references, which, in turn, I will match up with the seams in the soundboard slats; this will then allow the end pins to line up perfectly with the tuning pins, which were also drilled in with an analogous method at the other end of the instrument.  Then, returning the nut to its jig, I used a compass to draw circles at 15mm and 20mm from center.  These intersections I then marked to indicate alternating drilling points, like so:

The places with the hash marks (or crosses) are to be drilled.  I drilled a few test holes in some scrap to see which of the candidate pins would work best (I had several ideas:  brads, screws, etc.) and settled on brass-plated twist brads (no pix yet; to be revealed later).  To keep the alignment consistent, I returned to the edge circularizing jig (the one I used on the oscillating belt sander and the router table), now mounting it onto the drill press and tipping the drill press bed 5° to give the pins a tilt away from the direction of the pull of the strings.  After drilling the holes, I ended with this: 

And that is as far as I'm taking this blog post.  I have since cleaned up the markup pencil and begun pre-finish sanding on the nut.  Still remaining for the nut is to be glued to the body, which I'm holding off on only because I have this nagging feeling that I'll regret it if I'm too hasty, and for the brass rod to get a final fitting (i.e., hand-bending to get as nearly perfectly circular as possible) and possibly to be glued (epoxy? cyanoacrylate?) in place.  

Next post I plan to be about the bridges, which I have just begun to experiment with.  After that, there will be very little left of the complex, inventive parts of this build:  I'll need to make a support for the instrument (basically a couple of Ys to hold the axle), glue up whatever isn't yet glued and apply a finish (very likely shellac), put the strings on and tune it, and make a bow (the design of which is still unclear).  

Rotola: An Instrument Takes Shape

In my last post, I focused on finalizing the basic frame of the instrument:  two blocks at each end of an axle.  With that complete, and having given up on further refinement of the soundboard slats' radiusing, it was now time to attach the latter to the former.  This post will cover those steps.  

Before I could glue the pieces of the soundboard to the frame, a few things needed to happen to them.  First, they needed to be fit, i.e., cut to final width (or more properly, degrees of arc) and jointed along their long edges so as ultimately to create as unified a cylinder as possible.  Once that was done, the soundholes needed to be cut.  

Jointing was done in several steps.  First, one edge was selected as most straight; this was then made as perfectly straight as possible by either sanding or planing or both.  Given the thinness of the soundboard the wood was brought to the cutter, rather than the usual other way around:  for sanding, I used sandpaper attached to glass and, for planing, my #7 Stanley jointing plane was placed upside down in a vise and the piece of soundboard was moved along it.  Care was taken that the edge being jointed was perpendicular to the tangent of the cross sectional arc (or coplanar with the radius) so as to join as tightly as possible with the adjacent slat.  Hopefully, the below diagram clarifies this statement:

That done, a wheel marking gage was used to mark a parallel edge just a bit wider than the final width, e.g., given there were eight slats, each slat would be 22.5 degrees of the cylinder's circumference, so the edge would be marked at 23 or 23.5 degrees; translated into millimeters at the outer radius of the pinblock, this was something like 45mm on the wheel gage -- I don't recall exactly.  The excess would be planed down, then, if necessary, sanded to fit precisely with the adjacent slat with the same method as the first side.  Here I'm test fitting two pieces of the soundboard, taped to the frame:

Next, the eight soundholes needed to be cut.  This would normally be a tricky operation, made more difficult by the curve of the soundboard sections.  A typical way of doing this would be to drill holes into the center of each strip and then connect them by cutting with a coping saw or knife, risking splitting the thin and delicate spruce, requiring much clean up, and making it difficult to get them all identical.  Alternatively, one could make plunge cuts with a router or router table; this would require yet another jig -- probably a fairly elaborate one -- and, again, the curve of the soundboard would make it difficult to keep the soundboard stable during the operation.  

After much deliberation, I decided instead to route out half-holes on each side, which would then create soundholes between slats.  There were several advantages to this:  it would be a very simple operation on the router table and require only stops on the fence, rather than a jig, it would be simple to keep the soundholes neat, straight, and centered, since they would register to the precisely jointed edges rather than a curved face, and it would reduce the surface of the edges being glued (and thus save time during a tricky glue-up).  

I spent a fair bit of time testing with scraps and getting the table and fence set up and then proceeded cutting sixteen half-soundholes, two into each of the eight slats.  Rough off the router table, they looked like this:

As you can see, the routing left some rough edges, especially at the ends of each hole, but these were easily cleaned up with sandpaper.  Too, there were a couple of holes I screwed up, one in which the router bit climbed out of the intended hole and bit a little too far into the spruce and one where the bit chipped out the edge of a hole.  I managed to repair these passably well by cutting tiny bits of spruce, matching the grain as best I could, gluing them carefully into place and the filing and sanding them to the correct outlines of the soundhole.  

In the end, I was pleased with the overall results and, if I go with this soundboard and soundhole design again, will probably use this method to cut the soundholes.  It was a bit fiddly, but I think less so and much easier to make consistent than the two methods I described above.  

So, now I was finally ready to begin gluing up the body of the instrument.  I had numbered the strips to keep the jointed edges together:

Six of the eight are shown here.  Number one is off camera, either taped or already glued to the frame; number eight is yet to be finalized, as I decided that would be easiest to do once the rest are on.  (You may notice in the first pic above that the pinblock sections are numbered as well; they correspond with the slats.)

Gluing arc-cross-sectioned strips of wood to cylindrical hunks of wood using square-faced clamps was not easy.  I tried several configurations, one of which was this: 

Note how the two clamps on the right cross each other, each taking a basically diametrical orientation, which is the only way a flat clamp can get any purchase on a cylindrical surface.  The one on the left is serving to bolster the rope holding the soundboard down, as I could not get enough radial pressure with the rope alone; that experiment was not repeated as subsequent strips were glued.  In the end, I solved these problems by making custom, cork-lined clamping cauls (excuse the accidental alliteration); although I don't have pix of these glue-ups, the cauls show up some of the next steps.  Here is the instrument with more slats attached:

You can see the clamping cauls being used as supports there.  Next is a view of I believe the same stage (six of the slats glued) showing the soundholes:

The end result was not what I had hoped:  most of the slats had radii tighter than the cylinder they made up, which meant that, rather than being perfectly round, the tube of the instrument was slightly lumpy.  So, instead of having a cross section like this:

It's more like this:

This effect was further exaggerated by the need to scrape and/or sand some of the glue joints.  It is, however, largely an esthetic concern at this point.  Unquestionably, the unroundness will affect the sound of the instrument, but my goal here is to see if it will simply hold together and produce something like the sound I have in mind; presuming it does, I can experiment with the effects of structure on timbre on later iterations.  Presuming I do so, I have some ideas as to how to increase the chance of ending up with a nice, smooth, round cylinder, if that seems like the shape to pursue.  

One other outcome of this stage was learning something about the acoustics of a stopped, cylindrical soundboard.  The tap tones for the individual slats were decent; they were clear and reasonably sustained.  As I added each strip to the frame and glued them into an ever larger resonating surface, they retained this quality and I was increasingly excited about how the whole would sound.  However, after gluing in the final piece, the soundboard deadened dramatically; it is now much stiffer than I expected.  It has some resonance, but nothing like I had hoped.  In retrospect, this makes sense, but I'll share my speculations on that elsewhere.  Ultimately, this design -- a capped, tubular resonating body (as opposed to an open or stopped-at-one-end chamber, like a marimba) -- may not work.  I expect to experiment further with it later on.  

With the body of the instrument assembled, it was time to drill the holes for the tuning pins.  My original design (along with being octagonal and having both the soundholes and the bow at the other end) had only eight strings.  As a reminder:

Back when I was assembling the pinblock, I realized I had grossly overestimated the space I needed for the pins.  My ultimate vision for this instrument is of something much larger, with, say, 30 or 40 strings; being able to put more strings on this prototype would allow for a better proof-of-concept, so I decided to set it up for 16 strings rather than the original eight.  

After doing the layout for drilling the holes (which can be seen in one of the pix below), I needed to create a drilling jig.  Not only do the pinholes need to be perfectly radial (i.e., run from the surface of the cylinder exactly toward its center), but they also need to be tilted a bit along the longitudinal axis to counter the pull of the string; I decided, more or less arbitrarily, on five degrees.  (You can see this tilt in the pic above of the original design.)  To accomplish this, I repurposed the clamping cauls and set up a jig on the drill press thus:

The carriage bolts secure the jig solidly to the drill press table and the extension helps stabilize it.  In the next pic, it's easier to see the five degree rake.  

Setting up and doing the actual drilling was quite nerve wracking:  if I screwed this up, I'd have to scrap what I'd built so far and start over and, having spent more than two years on this project already, that would be a bad thing.  So, following the maker's adage "measure twice, cut once" -- or in this case, measure many times -- I forged ahead with a trial hole, which, much to my relief, came out exactly as planned.  Testing it with a pin: 

You can see the layout marks for the pinholes here; "x" marks the spot!  The first of sixteen holes being successful, I plunged on (sic) and completed them.  

The next step is to create, assemble, and attach the nut:

The nut also has had some significant redesign, but I will cover that in the next post.