The maple 1″×2″ is going to be the neck of your diddley bow (Figure 13-3 is an anatomical diagram of a generic string instrument). Decide which 2″ face looks nicest (and smoothest); this will be your fingerboard. Measure 2″ from the end of your fingerboard and draw a line across the board. Now measure 25″ down from this line, and draw a second line. Finally, measure 2″ further down (or 27″ down from the first line) and draw one more line. The first line marks the placement of your diddley bow’s nut (on a stringed instrument, the nut is a slotted guide just below the tuning pegs; it holds the strings in place, keeping them the appropriate distance from the finger board to prevent rattle—usually called fret buzz). The second line marks the saddle (which holds the strings in place at the tail end of the instrument and transmits their vibrations to the body of the instrument). The third line marks the bridge (the point where the strings are anchored to the instrument’s body). Run a wood saw over the saddle line two or three times, cutting in about 1/16″ or 1/8″. This will make it a little easier to seat the saddle later.

Adding the position markers illustrated in Figure 13-4 will make the instrument more playable: Measuring from the nut line, put dots at 3 5/8″, 5 7/8″, 6 7/8″, 8″, 10 1/2″, and 12″. Doing this with a Sharpie will make them easier to see; burning them in (as described in Chapter 8, Small-Board Go/Tafl) is much classier. These dots (plus the open string) give you one full octave of the blues scale.

Figure 13-3. The anatomy of a generic string instrument

Figure 13-4. A diagram of the neck with position marker dots, and lines for the nut, saddle, and bridge

Now sand the board. If at all possible, borrow an electric sander (Figure 13-5, left) for this step, as you’ll save a significant amount of sweat and time. Flip the board over, and sand down the two long edges on the back of the neck; you’re going to slide your hand against these a lot while playing, so you’ll want to take the edge down significantly. Sanding the front two edges will make for more comfortable playing but is not vital. Also sand down the front top edge of the face (that’s the area that corresponds to the lower-left edge of the neck in Figure 13-4, from the bridge line to the butt)—you’ll end up resting your right forearm here as you strum.

Figure 13-5. An electric sander (left) and sanding block (right)

Flip the board face up, and place it so that the bridge mark is to your right; from this point forward, all instructions assume that you have the diddley bow oriented with the bridge to the right and nut to the left. We’re going to drill the three holes illustrated in Figure 13-6:

Next, you’ll install the tuning peg. Although the makeshift tuning peg described in Step 6 works fine (and stays in tune very well), it can be a little finicky at first; a guitar tuning peg will be easier to deal with. Replacement pegs can often be purchased for a few dollars at a guitar shop. Tuning pegs come in several flavors; two of the most common variants are shown in Figure 13-7. The simplest (and cheapest) pegs are friction tuning pegs; they are basically what we build in Step 6 and not really worth the extra money. Better are geared tuning machines, which come in open and sealed varieties; sealed are much more expensive, and the cost is not really justified in this application. Since tuning pegs come in different lengths, make sure the one you buy is long enough to pass through the neck of your diddley bow—a peg that has a shaft about 1″ long (measuring from its base to the hole in the shaft) should be fine.

Figure 13-6. The left diagram shows the position of the tuning-peg hole on the diddley bow’s head; the right diagram shows the positions of the pickup-wire hole and bridge-bolt hole on the diddley bow’s butt. Both diagrams are to scale.

If you’re using a store-bought tuning peg, then drill the final hole in Step 4 a touch larger—around 1/4″—and install the tuning peg, pushing it up from behind and securing it with its included screws. Since these screws are usually both tiny and cheap, use a small bit to drill guide holes for them; brute-forcing the screws into the hard maple will just strip them.

Figure 13-7. A friction peg (left) and open-geared machine (right)

You can build your own friction tuning peg, shown in Figure 13-8, from a 3/16″ eyebolt, two 3/16″ washers, and a 3/16″ wing nut. Place one washer on the eyebolt, slide the bolt through the front of the 3/16″ hole at the head of your diddley bow, add the second washer to the back, and spin on the wing nut.

Figure 13-8. The homemade tuning peg installed, viewed from the back

Cut a 1 3/4″ length from your hardwood dowel. This is the saddle.

Set the neck aside, place the cookie tin bottom up on the workbench, and drill a 1/2″ hole through the middle (this is where the bridge bolt will connect the neck to the resonator). Then drill a 3/8″ hole into the side of the tin. This hole is for the guitar jack, so most players will want it to be on the instrument’s tail; if you prefer, drill both holes in the bottom of the tin, which will be the face of the diddley bow’s body. Line up the 1/2″ hole in the neck with the 1/2″ hole you just drilled in the tin. Using the neck as a template, drill a 3/16″ hole in the tin that matches up with the 3/16″ hole in the neck (the orientation of the three holes is shown in Figure 13-9). The pickup wires will ultimately pass through these holes and to the jack. Don’t worry if these are a bit ragged; all the edges will be on the interior or covered by hardware later. If they are very rough, smooth them out with a few swipes from a tapered half-round file (see the appendix for details).

Place the neck face up on top of the cookie tin, lining up the 1/2″ holes. Slip the ball-end of your guitar string into the hole and then your 3/8″ bolt. Flip the diddley bow over, slide the washer over the bolt so that it sandwiches the string against the inside of the cookie tin with its ball-end peeking out, then add the wing nut (as shown in Figure 13-10). Be sure that the pickup holes in the neck and cookie tin are lined up, and tighten the wing nut into place.

Figure 13-9. The cookie tin, drilled to accommodate the bridge bolt (through the hole in the center of the silver bottom), pickup wires (through the small hole located at one o’clock), and the jack (which will be installed in the hole on the side of the tin)

Figure 13-10. Locking the string into place

Flip the diddley bow back over and thread the end of the guitar string through the eye of the tuning peg. Pull the string tight, then back it up, adding 1″ of slack. Bring the free end of the string toward yourself (i.e., counterclockwise), loop it under the length of the string, then pull the end of the string up and back, crimping it where it crosses under (these three steps are demonstrated in Figure 13-11).

Figure 13-11. The three steps to properly stringing any steel-stringed instrument: (1) Give 1″ of slack, (2) Pass the free end under, and (3) Kink it up

Begin to tighten the string with the tuning peg turning clockwise (Figure 13-12; if you’re using a tuning machine, this may mean counterintuitively turning the knob counterclockwise). In order to accomplish this with the homemade peg, you’ll need to twist the screw clockwise a turn, then hold it in place while you lock down the wing nut with your free hand. It’s a little awkward at first.

Figure 13-12. A properly wound string with floating matchstick nut

Once the slack is out of the string, slide the piece of dowel from Step 7 under the string and line it up with the saddle line. Then slide a matchstick under the string, and align it with the nut line (as in Figure 13-12). The matchstick may seem a little ridiculous, but it’s a practical choice: Matches are made from aspen (which is soft but fairly strong) and are easy to replace. Any dainty scrap of wood put under the strain of a tuned guitar string is going to split eventually; just replace this “floating” nut whenever you re-string the diddley bow. (Actual guitar nuts are made from dense plastics, metal, or ox bone. Bone blanks can be bought at most guitar shops that sell replacement parts. If you want a permanent nut, buy such a blank, shape it with a file, and glue it into place.) A strung diddley bow is shown in Figure 13-13.

Figure 13-13. A strung diddley bow

Tune the string up to G (or whatever pitch sounds good to you). The first G that you hit will actually be the G below the G on a guitar in standard tuning (i.e., the highest note on a bass guitar, two Gs below middle C). Since the lower tension will be easier to play initially, you might want to start here before tuning up to the standard G. The string will need to stretch somewhat, so expect to have to keep tuning the diddley bow back up to pitch for the first 10 or 15 minutes of playing around. You can speed this process up by tuning to your pitch, then pressing the middle of the string (near the last fret dot) all the way to the fingerboard, tuning back up, and repeating.

Either coil up the excess string or snip it off using wire snips. Do not use scissors or the diagonal cutters from your soldering kit! The hard steel of a guitar string will notch these delicate blades, ruining them.

To start your pickup, cut two 1″ diameter circles from the playing card, stack the two magnets, and Krazy Glue one circle to either side of the pair (making something like the body of a yo-yo, shown in Figure 13-14).

Figure 13-14. The body of the pickup, ready for winding

You’ll need to wrap roughly 1,500 windings of 42-gauge enameled wire around these magnets. This wire is only a little wider than a human hair and not quite as strong. When the glue on your playing-card-magnet yo-yo is dry, stick the magna-yo-yo to the side of your desk or a filing cabinet. Leaving 9″ or 10″ dangling, loop the wire once around the magnets (like winding a yo-yo), and then continue winding in this manner—don’t rush; it’s very easy to snap the winding wire (and then you’ll need to start over). Once you get the hang of it, you can put 250–300 windings around the pickup in about 5 minutes. Carefully working in 5 minute intervals, it shouldn’t take you more than 30 minutes to wind a pickup like the one shown in Figure 13-15.

Figure 13-15. A freshly wound pickup

1,500 windings will result in a nice clean pickup (no hum, little noise), but one that is also relatively low-level (or cool). If you need it to produce a hotter signal, simply add more windings (although keep in mind that hotter pickups are more prone to hum).

When the pickup is wound, you’ll want to add wires that will put up with more abuse than the 42-gauge winding wire. Cut two 8″ lengths of 24-gauge insulated hook-up wire, strip the ends, and tin them (for details on soldering, see the appendix). Solder one of these wires to each of the two 42-gauge wires dangling out of your pickup (the enamel insulation on the 42-gauge wire will melt away under the soldering iron’s heat, so you don’t need to worry about stripping them, although you can do so using coarse sandpaper). Wrap a little piece of electrical tape around one of these solder joints so that the two don’t short each other out. Solder the other ends of the insulated wires to the two lugs of your guitar jack (Figure 13-16); it doesn’t matter which wire goes to which lug.

Figure 13-16. Leads and jack attached, ready to test (note that the thin pickup wire is almost invisible when viewed from a foot away)

Test your pickup by carefully plugging it into an amp and gently tapping on it. It should boing and clatter, and it will definitely thunk when you bring it close to a magnetic screw or nail. If the pickup works, go ahead to the next step. Otherwise, make sure your amp is working, then check the solder joints on your insulated leads and jack. If those look okay, then there is either a break or short in the pickup itself, and you’ll need to pull off the 42-gauge wire and rewind the pickup. Once you have a working pickup, loop all of the trailing 42-gauge wire carefully around the pickup, followed by a loop or two of the insulated leads. Squirt a little Krazy Glue into the “yo-yo” to hold these wires in place, and set it somewhere to dry (preferably on top of waxed paper, so you don’t end up gluing it to your table).

Even a tightly wound pickup will boing and clatter whenever you touch it, since the minute shifts in the coils will generate a fluctuating current in the presence of the powerful magnets. In order to cut this noise, we need to pot the pickup, which means soaking it in molten wax to immobilize the coils. Place the beeswax in a clean glass jar, place the jar in a pot with a few inches of water, and place this over medium heat until it has just melted, then cut the flame.

Dunk the pickup in the molten beeswax for 1 minute—tiny bubbles will drift to the surface as the wax soaks into the little crevices between the windings. Pull the pickup out and let it drain and cool for 30 seconds. Then dip it for another minute, let it drain for 30 seconds. After the third or fourth dip, you shouldn’t see any more bubbles when you soak it. Leave it hanging over the lip of the jar to cool (Figure 13-17).

Once the pickup has hardened, plug it into your testing amp. Tap it, and you’ll notice that it’s now quiet (although you’ll still get a good racket when you drop a screw on it). To install it, desolder the guitar jack and thread the wires through the 3/16″ hole in the neck, then through the 3/16″ hole into the cookie tin. Resolder the jack, and mount it in the 3/8″ hole in the tin, as in Figure 13-18.