8-string electric guitar conversion

Adding 2 extra strings (Chikari) to an electric guitar as an adaptation for Hindustani music.

As my first experiment, I chose a $15 Goodwill special (First Act) just to see what the results would offer.

I cut off most of the old headstock at a 15 degree angle and grafted some grain-matched maple in the same way I would on a custom guitar neck. It creates a very strong neck, as the wood grain runs parallel to the headstock (instead of at 15 degree angle) and therefore more resistant to breaks.

 When done correctly, you can barely see this joint!

I always laminate a veneer on the top, in this case Brazilian Rosewood. This dresses it up, and adds a lot of strength to the joint (not that it needs it):

I used the stock black tuners for the 6 playing strings, and two spare Gotoh's I had for the chikari. For a higher-end job, where appearance is a concern I would use matching tuners. Since there are 8 strings involved, nice mandolin tuners would be an option.

For the bridge, the fixed-bridge they had on there turned out to have enough room to drill to small holes, spaced just right from the bass string, to run the two chikaris through. All that was left was to make a small bridge (out of steel 1/4" stock) to hold the chikari's about 2 mm above the plane of the melodic strings:

This is somewhat crude, and I may look into developing a seventh adjustable saddle bridge, or look into ordering custom 7-string bridges as replacements on higher-end jobs. But it works...

On the nut end, I just created a nut that extends about 3/8" past the bass end, and left it so it could be shaped to hold the strings (again) about 2mm above the plane of the melodic strings (that comes from my friend who plays sarod in the Shah-Jahanpur gharana- they have their chikaris about 2-3mm above the main strings):

 A pretty straightforward conversion, with lots of room for adding tweaks to make it more adjustable, extra strings, tunable by capo, etc. etc.

I will upload a video someday if I get the time! Contact me if you have any questions on this process.

Note: Cut your guitar up at your own risk!!!
'Crafting a nut' and 'grafting a headstock' are terms I'm using lightly- it took me about 8 years to get my chops up on that stuff building custom instruments, and I wouldn't necessarily recommend for the DIY'er unless you have a lot of experience!

Pterocarpus Erinaceus

Pterocarpus erinaceus: wood used to make musical instruments in West and Central Africa. Used for, among other things, djembe and mbira. The native Shona word for this tree is mukambira.




I had noticed that the wood on many mbiras I saw was similar to many of the djembes I have seen- but did not resemble any hardwoods I am acquainted with. Turns out most are made from this tree.

It also turns out P. Erinaceus is part of the legume family, as are the rosewoods that are so desirable to luthiery as tonewoods. Also in the legume family are acacias (incl. Koa), locusts, bubinga, wenge, and purpleheart, among others.

Kid Kalimba Month!!!

SPECIAL HOLIDAY NEWS!

Blinknow.org and Holiday donations &
Kid Kalimba celebration

A friend posted this video online, which I found incredibly inspiring. Maggie Doyne did something I think we all at some point wish we could do: give our lives over to the betterment of others. But I found her amazing story so refreshing and inspiring:

Maggie Doyne — Why the human family can do better from The Do Lectures on Vimeo.

So I decided to DONATE 10% OF ALL SALES TO BLINKNOW.ORG through January 2014.

At first, I thought, I should move the family somewhere we can devote our lives to helping others. Sure it would be a major disruptive change, but it is the right thing to do.

But then I realized, despite the best intentions, we are not all meant to do service work. I could give you a dozen reasons why that would be a horrible idea, for me personally as well as my family. Is this a copout? Not really. I intend to volunteer (and encourage my kids to) on occasion for any projects that I can find throughout my life, but that is not the main fulfillment of my abilities and passions as a person.

I also realized, that in my own way, I CAN help people directly- by donating money I make doing what I love, and doing what I am good at, I can devote my life's work- making musical instruments- (at least in part) towards helping people.

So to celebrate, this is KID KALIMBA MONTH!

These instruments are made for kids, make great gifts for the holidays, are crafted from local sustainable materials, and part of the proceeds go towards helping children!!
Buy One Now

Buy as many as you can for the kids you know, and tell your friends about them as well!

Happy Holidays,
Josh

Jarana Veracruzana repair

This instrument is interesting in many ways. It is made of a nice smelling pine-like wood most likely endemic to the region:

The entire back, sides, neck and pegbox are carved from a single solid piece. The only glued on parts are the soundboard and fingerboard!

In this shot you can sort of make out how the sides were carved out before the soundboard was added:

And here you can see the back, neck all as one piece. It may look like a glued joint, but it is one continuous piece for the entire thing!

The other interesting thing to note, is that although the strings are separated at the nut into 5 distinct courses, for fretting chords, at the bridge all 10 strings are equally spaced:

I think the intention of this design is to have an even sound strumming across all 10 strings. There would be little melody playing done on an instrument like this.

In jarocho son music, the rhythmic strumming is very important. This type of instrument provides rhythmic strumming, and chords, while other instruments and singing would provide the voice.

I love seeing how instruments are built suited to a particular style of music.

Drumroll please.... here (hear) is the sound of the Esraj with mylar head! Kishan Patel does an amazing job in this performance:

Esraj final

One portion of the rim epoxy came loose after gluing; the job was salvaged by heating and molding the shape of the mylar over the rim, and gluing it completely around the edge with a 3M adhesive, Super 77. The stuff was very gooey and gross to work with, but did the trick- strong tack and fast, durable bond.

Here we are tuning and setting the bridge position:

And it was just in time! Here is a photo from a few days later, in concert with Arijit Mahalanabis, Samir Chatterjee, in the very able hands of Kishan Patel

Esraj head gluing

Here she is stretched on a frame:

and now with epoxy and clamps and weights (I eat heavy peanuts):

Fiberskyn esraj head replacement

I do work on North Indian instruments quite often; sitar, sarod, tabla, etc. People have asked about replacing the traditional sheep or goat skin with a synthetic material, and now I have the opportunity to test it out.

This esraj had a large chip missing from the bottom rim of the bowl. I removed it, squared the edges, and prepared a piece of cedrela oderata which is an excellent match visually and for strength/weight ratio to patch it.

I shaped the new piece to match the rim, and scraped the excess sheep hide and glue from the gluing area of the rim. The patch ties in to a vertical support beam- one that is VERY sturdy- which will carry the string tension through to the neck. I am very confident this repair will hold, even with the very many strings putting tension on the assembly.

The next step is to test adhesives on the Fiberskyn head. Remo makes this excellent synthetic imitation skin. I chose the ambassador weight which is 10 mil thick. This matched a few samples I measured of the sheepskin from the instrument.

The material is mylar, and I opted to test three adhesives: cyanoacrylate (super glue), E 6000 (an industrial adhesive for exterior gluing on cars- recommended by 'the glue guy' at the hardware store) and long-cure epoxy.

I made a scrap assembly resembling the bowl. First I only glue the pieces to the top side of the rim (not wrapping around the edge for extra strength).

I applied some finger pressure, and both the epoxy and super glue broke wood away before giving up the bond. The E6000 bond broke quite easily; I would say I was only applying ca. 20 pound of finger pressue.

Next, I reglued the samples OVER the edge, to add strength. This mimcs the traditional attachment, and will really test the adhesives. Here is the result:

As you can see, I was able to clamp the mylar clear to the bottom of the channel; I would estimate forces in excess of 250 pounds and both the superglue and epoxy held fast. The mylar stretched to accomodate the pressure, and the glue bond held.

However, the E6000 let go after only a few turns of the clamp. Clearly, E6000 adhesive is not formulated to bond mylar.

I will feel very confident using superglue or epoxy. The epoxy was easier to bond the top of the rim with, so I will probably use it for that purpose. The superglue was much easier to use pulling the extra over the edge: the result also looked cleaner, and since that is the most visible part of the repair, I will probably use superglue for that.

Chromatic kalimba: possible tuning layouts

A customer recently asked me about potential note layouts on chromatic kalimbas.

I have crafted instruments with chromatic notes immediately adjacent, in linear ascending fashion, as well as Hugh Tracey style, where the chromatic notes are on the back surface of the instrument. I have also found a nice way to combine approaches, and essentially take the Hugh Tracey diatonic layout, and add chromatic notes adjacent to each pitch. This gives more pitch separation than the linear layout, but less than the Hugh Tracey arrangement.

I am not a physicist, so I have to go on observation of the work I have done.

I have found instruments with chromatic notes closer to each other to have more pitch separation. C and C# have very few overtones in common, so notes struck tend not to excite their neighbor notes by harmonic resonance. If there is a loss in sustain (from the fact that the note is not supported by sympathetic resonance of nearby notes) it is so minimal as to be not noticeable. And, a well-constructed kalimba could be built using dense woods to enhance sustain and clarity.

Hugh Tracey-style puts triad notes (chords) next to each other, giving a harmonic resonance- a very rich sound where the notes tend to blend into a wash of whatever the scale its tuned to. The harmonic similarity is only skin-deep though; if the instrument is tuned to equal temperament, even the I to V relationships are very slightly out of tune, and have little overtones in common. There will still be more overtones of a similar, if not exactly equal, resonant frequency.

Therefore, my idea is that if you want more of a modal, harmonically rich sound (sounds great, but only in the given mode or key) then go Hugh Tracey style and separate the notes as much as possible by grouping into triads. If you are musically more adventurous (most people using chromatics are!) then use whichever key arrangement gives you better access to the notes- the pitch separation will be there and I don't hear a major loss of resonance or damping by neighbor keys,

It is interesting to note that Zimbabwean mbiras are tuned with ascending scale tones immediately adjacent. The right hand notes are half and whole steps apart. There does not seem to be a problem in terms of richness of sound and resonance there!

Banjo 5th string tunnel (dual)

In creating a banjo for a lefty, I decided to tunnel the 5th string. I realize that this would prohibit the instrument from ever being set up right-handed, save carving a new neck. Anticipating that this banjo will be around long enough to potentially be in the hands of a righty, I decided to add dual 5th string tunnels.

The unused channel does not get in the way, negatively affect tone, etc; it only increases the instruments versatility. I also left the fingerboard a constant width to the nut in order to facilitate.

Here is a view of the brass tubes used for tunneling:

The termination of the rods at the nut end looks like this:

A hole is drilled in the nut to allow the string to escape; if the instrument is ever retrofitted for a R.H. player, a new nut would simply be made with the hole drilled on the other side.

Here is a view of the brass tubing exiting the fingerboard just before the 5th fret:

As you can see, I have inserted .020 wound strings in to the hole. These prevent the tubes from crushing during bending, and as you pull them out, clear out any debris or adhesive that may have got in. This fingerboard is ebony, bound in cherry and ebony.

Antique Stanley Pullshave

At the Picadilly Flea Market today (Eugene, OR) I scored this Stanley tool- the seller called it a pull scraper, but I believe it is probably better known as a pullshave. Veritas and Stanley both make modern versions of this tool, but I couldn't seem to find any pictures or references to this old Stanley model, presumably antique.


I know furniture builders use this type of tool to hollow out the inner curve of a chair seat, and wooden boatbuilders would also find it useful for all of the inner curves they work with. I am thinking it could come in handy for luthiery, either in carving necks where I use a spokeshave quite a bit, or in hollowing out the inside of an archtop soundboard.


The modern versions offer an improvement in the addition of a handle above the blade- this would give more control of the cut. At any rate, I think once I tune it up it should be a joy to use! The handle is very comfortable and feels massive- like it has the right mass to balance a steady pull.

I also think its cool that at least two tools in daily use- the vegetable peeler and the shaving razor- operate on the exact same principle. It somehow makes using these tools that much more comfortable.

MYRTLE

Myrtle is a wonderful wood to work with. I used to bend it wet, but I have found that bending with no water actually works better- you get little to no cupping effect, whereas when I've used is wet it has often cupped quite a bit (not unlike maple).

Tonally, it seems to be bright and reverberant. I think it supports a crispness in the sound, and seems overall brighter than mahogany or walnut. I don't think that the bass suffers though- the high frequencies enhance the definition of the bass tones, and possibly the sustain as well.

Take this all with a grain of salt of course- I believe that most of the voice of the guitar comes from the bracing design and execution above wood choice, by a large amount. The wood just seems to accent or reinforce certain tonal aspects more than others depending on the species.

INSTRUMENT VOICING

The most useful technique I have found is what I would describe as a sort of creative process of imagining the sound transformed by guitar strings/tension. If you tap every piece of wood regularly as you shape and construct the guitar, and also tap parts of completed instruments and various instruments you own, you begin to develop a sense of what the wood sounds like, and how that sound interacts with the vibration of strings under tension. As you refine this perceptive ability, you can begin to creatively imagine how each part will sound in the completed instrument by tapping as you work on it.

More specifically, by tapping I mean holding the piece of wood approx. 1/9 of the length in from the edge, lightly pinched between two fingers. This is derived from Young's modulus, or the vibration of free bars (which most pieces of wood resemble before being glued into a box shape). Each piece of wood will sound different, and some are more musical than others.

For example, dense wood such as rosewood and ebony tend to have a loud and clear pitch, like a marimba bar. Softer or less dry woods will have a muted, unclear note, and most other woods are somewhere else in between. I believe that all pieces of wood in an instrument contribute (even if an imperceptibly small amount) to the overall musical vibration/resonance, so in a handcrafted instrument it is essential to select the most musical sounding wood, or to shape the piece sin such a way as to accent that characteristic, regardless of the species.

Good compilation of tonewood sources

http://www.coneguitar.com/tonewood.html

Thanks Cone Guitars for this thorough list.

Oregon locals should add:

Urban Lumber
2440 Main Street
Springfield, OR 97477

(541) 988-9663

Apple wood as tone wood for bouzouki

Lately I've been experimenting with apple wood as tonewood. It compares in density with cherry, a bit softer than maple, beautiful color, and is stiff and musical when tapped.

Apple tonewood is all but impossible to come by. About 6 years ago I had a huge (almost 4' diameter) apple felled in my back yard. I had it milled and dehumidifier kilned, and then it air dried for about 5 years. Just now, it is coming into it's own sound-wise- I resawed a piece of it and the nice tap tone made me want to try building with it.

Here is an Irish bouzouki I recently built with the apple from my yard.:

The sides bent easily and the wood has a smooth surface feel that takes finish beautifully. I am also encouraged by the tone- I would say it is more in the warm type of tonewoods like mahogany or walnut, but it also seems to have clarity and sustain in the high register. It's actually right in the pocket of what I seem to go for- granted design, bracing and top wood play a much more substantial role in the equation, but the apple seems well suited for stringed instruments.

Cocobolo: a dream to bend!

It was exciting to bend cocobolo for the first time- one of the most dense woods I've ever worked with! It rang like a marimba bar when struck, and planed smoothly, but I dreaded the actual bending. Then- surprise!- it bent so smoothly!! Perhaps the best wood I've ever bent. I absolutely love bending the wood, by hand, over my propane fueled bending pipe. At any rate, I was surprised, but ended up with the smoothest sides.

I had some alaskan yellow cedar that was not quite right for instrument material, but it made an excellent kalimba case! Aaron Chavez, master player of the chromatic kalimba, custom ordered this four-octave (yes, four octaves!) fully chromatic instrument, of his design.

The bass keys hang over the treble keys, so that you can double a note or chord with a bass note two octaves below simply by touching the key 1/2" or so below it! The chromatic notes are on the back side, the flat notes behind their corresponding naturals on the front.

The kalimba is imbuia and walnut, and that gray foam padding inside the case is IMPOSSIBLE to find- even though it comes with virtually every electronic you'll ever buy!

 

This apple tree stood in the back yard of our last home- one we built in Eugene, Oregon. It had been long neglected and despite several years of careful pruning, it never produced many apples, and had some serious rot issues. We cut it down, sadly, but the result ended up being great. The garden saw much more sunlight, and I managed to get about 1000 board feet of usable lumber out of it!

The tree was over 3 feet in diameter at the base. It yielded several sections of 18 to 20" wide trunk wood, which when sawn on the quarter gave me a bit of wood I thought might work as tonewood. The sections ranged from about 4 to 7 feet long, so there is plenty of material to use for some cabinetry in the future.

After an initial run in a dehumidification kiln (no heat, just blows air over it to carry away moisture quickly) I stickered and air dried a few pieces that looked like possible tonewood for about 4 years. I finally had a chance to build with it, and created this octave mandolin/ bouzouki. It looks and sounds incredible, and I am very happy to know that the apple turned out to be a useful tonewood. I would compare it's feel/workability/tone somewhere in the range of walnut or mahogany.

Federated Teachers Service Corporation parlor guitar

On the bench this week is a Federated Teachers Service Corporation parlor guitar. It appears to be from the 1950's or earlier. Through a little Googling, it seems the instrument is in the same jumble as Regal, Harmony, Stella, Galiano, having derived from Oscar Schmidt's work. It has dyed maple bridge, and a dyed maple or birch fingerboard. It seems the neck is poplar, which was commonly used for these instruments. In my research another mention was made of a lap steel- interesting since this guitar came with two nuts- one for normal playing and a tall steel one, presumably for lap steel playing! The fingerboard also has fret numbers at each fret written in by hand, in yellow!

An interesting thing about this instrument- I tried removing the bridge to either reglue or replace it, and even with all of my forces (heating iron, heated spatula knife, various wedges and prying devices) I couldn't even begin to budge it. I think it may be epoxied in place, as that is the only other adhesive I have encountered with that much staying power!

Up and running again!

With the new soundboard, and a redesigned tuning, the chromatic kalimba is sounding much better! Unfortunately, that means now it is on it's way to Beijing.

The thicker soundboard seems to have increased the resonance, and pairing octaves of similar notes together also increased the sustain quite a bit. I just love the way the cherry figure pops out with the finish on...

Urban Lumber - Springfield

Visited Seth at Urban Lumber this morning for a simple planing job. It is always a pleasure to swing by his place. Right now he is mid-remodel, expanding both his shop and retail space, and adding a gallery/showroom as well. This photo shows his trusty ol' crane truck, which he used to haul my apple tree out of my yard a few years ago, which he then resawed and de-humid kiln dried.
Seth is inspiring because he really does things right- he is down to earth, and approaches everything from a fair and reasoned perspective. He also works BIG- big logs, big trucks, big slabs of incredible lumber, and big tools. He just added a wide-belt sander capable of handling extra wide boards (his old one went up to 36" wide, and the new one even wider!)
Next time you're in Springfield, swing by his place at 2440 Main Street- there is always something interesting to see and it is always worth a visit!