Make an Inbindi

This page contains instructions for making an electric inbindi. You could call the instrument an electric washtub bass, but we don’t use a washtub. Instead, we use a solid body earth-board with a piezo pickup. This gives the instrument a clear tone, ultra-low bass notes and long sustain. The electric inbindi is really its own instrument.

We believe Walley Electric Inbindis are the finest in the world, but we also want as many people as possible to give the instrument a try. So, in the hopes that together we can spread the popularity of the inbindi, here are some instructions for making your own. We have tried to keep them simple but detailed enough to create a high quality work of musical art.

We can’t teach woodworking or electronics skills as these subjects are simply too big. We don’t specify all details because, as discussed below, every instrument should be unique. Also, the techniques you use will depend on your choice of materials and the tools and skills you have. We can show the results of each step, but we can’t always show you exactly how to achieve them.

Safety is the most important skill.
Do not attempt the project described here without taking all proper safety precautions. If you are not familiar with the proper safety precautions, do not attempt the project. The authors accept no responsibility for damage or injury resulting directly or indirectly from following these instructions or attempting this project. Use these instructions at your own risk.

Look and Feel

Custom inbindi (in stand)
Custom inbindi (in stand)

In its most basic form, inbindis are easy to make. It is an ideal project for a woodworking shop class. However, you may not want its most basic form. A complete stage performance is not just about playing the right notes, it is also about looks and a few other intangibles.

At this time, most audiences will be seeing the electric inbindi for the first time. The instrument and its player will be under extra scrutiny. Assuming you have something to say musically, you will want the audience to listen with open ears and open minds. A poor looking instrument will be difficult for the audience to get past.

Audiences are more likely to open their ears if they get a sense of the historical and artistic context of the instrument. The inbindi is an ancient instrument that has played a role in the development of Jazz, Blues, Rock & Roll and many other styles from around the world. You are missing a golden opportunity if your instrument does not touch on its roots and weighty musical contributions.

We have audience-tested a number of different looks including hillbilly, comedy, home-built simplicity and ultra-modern sleek. In our experience, a nicely finished, carefully constructed but low-tech traditional African look gets the best response – hands down. A simple instrument built in a day is enough to learn how to play, and may sound excellent, but for the stage you will want your instrument to look sharp.

Tradition

The European tradition has seen instruments evolve to a somewhat standard form, but not the African tradition. African instruments are unique works of art. Instruments are thought to have individual personalities and sing with their own voices. Square corners, straight lines, symmetry, precise measurements or perfect materials are not needed nor desired. The plans on this page may not be as exact as you are used to – remember you are creating a unique work of art.

African tradition also includes the use of local materials. Our Jamaican-made instruments use materials from the Jamaican jungle. Our Canadian-made instruments use diamond willow and maple from the northern forest. Wherever you live, look around for materials that will sing about your home.

Just as adversity can shape human personalities, adversity can strengthen the personality of the instrument. Bob Marley sang “the stone that the builder refuse, will always be the head cornerstone”.
Knots, cracks, roughness or bits of bark may be reasons to choose your materials, not reject them. Ancient inbindis used bark to cover a pit, so a bit of bark on the earth-board is a nice touch. Your local lumberyard may be delighted to give you a good deal on imperfect but beautiful wood.

We like diamond willow because it is actually the result of a fungus that attacks willow branches – the beauty results from the willow’s struggle to grow around and past the trouble spots. We like maple for the earth-board because it is a strong hardwood that finishes beautifully, and – well, we’re Canadian – but also because one day we stumbled on a rough board that just seemed to sing.

The African tradition is also that great care is taken to make and maintain instruments. Imperfect wood should not be confused with dirty wood. Using local, stressed materials is not an excuse for sloppy work.
Materials should be cleaned, sanded, decorated and finished with care and patience.

You may want to consider some of the symbolism of the instrument. The earth-board represents mother earth, while the staff represents a tree reaching for the sky. The earth-board is female and the staff is male, and the two parts are married into one instrument when tied together with the string. The staff can reflect ancient roots, while the earth-board, with its electronics, is modern. Rather than making the two parts match perfectly, you may want them to reflect these symbolic differences.

Sound

Raw materials make a difference to the final sound of the instrument. Some of the difference is intangible, but a bit of physics helps point the way.

Much of the difference between acoustic and electric instruments is in the ‘ring’ or ‘sustain’ of the sound. An acoustic stringed instrument is designed to transfer energy from the string to the air. To get a loud sound, lots of energy needs to be transferred, but this means the string quickly loses energy and volume. In an electric instrument, only a small amount of energy needs to be transferred to the pickup – the amp solves the loudness problem. A slower transfer means the string vibrates longer. This also means the player of an electric instrument does not have as much physical work to do.

The staff can lose vibrational energy to internal friction and to the player’s hand. A heavy staff will vibrate less and reflect some energy back into the string. A hefty and strong staff will result in the best sustained ringing tone.

Strength also helps to eliminate creaking and cracking. This may not be much of a problem with an acoustic instrument, but with a pickup a tiny bit of creaking can be amplified into loud cracks and pops.

Practical Considerations

There have to be limits to tradition – unless you want to make an authentic inbindi starting with a pit in the ground. One of the great things about the Electric Inbindi is its portability. For even more portability, breaking the staff into two pieces is a nice touch. Doing this without weakening the staff requires some skill and patience and may change the sound of the instrument, so it is not always recommended.

As explained above, we purposely do things by eye, avoid making measurements, and prefer some imperfection. There should be some balance to this design philosophy, though. If the staff is too crooked the vibrating string might hit it. Any imperfections that significantly weaken the instrument, including crookedness or too much arc in the staff, are not good. Sometimes precise measurement is needed, for instance, where modern electronic parts are involved.

Making a String-Pickup

The Electric Inbindi uses an integrated string-pickup, that is, the pickup is a permanent part of the string. The bottom end of the string has a pyramid of epoxy with a piezo pickup element embedded inside. You make a mold by folding a piece of cardboard into a pyramid. The pyramid shape distributes forces evenly while holding the pickup steady.


You will need:

  • 6 feet (180cm) or more of 1/8 to 1/4 inch (3cm to 6cm) rope, such as woven nylon;
  • Piezo element (can be found at an electronics store, or online suppliers such as Digi-Key;
  • Card stock, cardboard or heavy construction paper;
  • 2-part, epoxy glue;
  • Masking tape;
  • Mixing sticks, toothpicks.

Pyramids

You will need to fold a couple of cardboard ‘pyramids’ – one to act as a mold for the pickup, another as a reference for carving the pickup cavity. For the reference pyramid, start with a 21/2 inch (65mm) square of card stock or heavy construction paper. Fold along the 2 diagonals.

Pinch one side so that it folds inward while the other three sides form a triangular pyramid. Secure with tape. Keep this pyramid as a reference for carving the earth-board.

Make another pyramid. This one will be used as a mold for the pickup. Eventually it will be trimmed to less than 2 inches (5cm) on each side, but you can start with a larger square. The 2-inch measurement is the maximum size that will fit in a Walley Electric Inbindi. In most cases the pickup can be kept smaller than this, making it easier to add felt padding later on for eliminating outside noise.

 

 

 

Choosing a String

There can be a great deal of debate about the ideal rope, wire or other material for making strings. It comes down to individual taste. To make a long story short, get some 3/16 inch (5mm) woven nylon rope (simple braid with no core). To make a short story long, click here to read more about factors for choosing a string – strength, weight, looks, stretch, consistency, comfort, noise and durability.

Piezo Element

A piezo element converts vibration into an electrical signal. Typically, they consist of a metal disk with a white ceramic substance glued to one side. Most will have two wires, one connected to the metal and one to the white substance. Some do not have any wires, which is a problem – soldering a good electrical connection is difficult or impossible, so it is best if the connection has been made for you.

The size of the disk is not a big factor in sound quality – adjusting your amp usually makes much more of a difference. A small disk is preferred because a smaller overall pickup makes it easier to add extra felt padding to cut down on outside noise. At least in theory, you can cut a piezo element, but if you break or crack it you may lose too much signal strength, or create a buzzing sound from loose pieces.

Piezo elements convert vibrations into electrical signals, but also convert electrical signals into vibrations, so in a pinch you can find one inside a piezo buzzer. Break or cut open the case and fish out the element (without bending or breaking it). If there are bits of glue stuck to it then cut or clean off as much as you can. Some will have a third wire connected to a small section of the element – trim off and ignore this connection. You may need to solder on some longer wires (a ‘coax’ cable is the absolute best).

Piezo element inside buzzer
Piezo buzzer showing parts after top is sawed off.

A piezo element is very sensitive and will pick up vibrations from anything it touches, including any bumps and scrapes caused by simple handling of it or any solid it is attached to. Careless handling while connected to an amp can hurt your ears and the amp. Our design calls for felt padding to isolate the pickup from outside sounds as much as possible.

Also, a piezo element is high in something called ‘electrical impedance’. Plugging directly into an amp works, but you may find the sound is a bit ‘tinny’. This is because most amps are designed for a lower impedance. With some amps, especially older amps, guitar amps or PA systems, the piezos’s impedance is just too high and the sound is horrible. If your amp has a special ‘high impedance input’ you should use it, but unfortunately a piezo’s impedance may be even higher than what this input is designed for.
The solution may be as simple as using the tone controls of your amp, turning up the bass and turning down the treble.

High impedance may cause a second problem – there is an increased chance of the patch cord acting like an antennae and picking up electrical interference resulting in an audible ‘hum’. This may be solved with a shorter, higher quality ‘coax’ patch cord.

If you are still unsatisfied, or if you plan on using different amps, you will want to add a ‘pre-amp’ as close to the piezo element as possible. If you are electronically inclined you can build one into your earth-board, or you can buy a pre-amp that sits on the floor, is part of a patch cord, or is worn on your belt so you have tone and volume controls at your fingertips.

If you are planning on going to some jam sessions (and we hope you do), a pre-amp can greatly reduce the need to adjust someone else’s amp by making the electrical characteristics of your signal closer to an electric bass guitar’s signal. In extreme cases, an amp or sound system may be unable to handle your signal without a pre-amp, and you should sit out before serious damage is done to equipment or ear-drums.

Pickup

Punch hole
Poke a hole through point of the pyramid.

Cut or poke a hole through the point of the pyramid. Tie a simple knot at the end of the string, trimming as much excess string as possible. Feed the string through the hole.

Feed string through
Tie knot at end of string and feed through hole.

Pull the string through the hole so the knot is close to the hole (but do not pull tight). Use tape to seal around string (to prevent leaks when the mold is filled with epoxy). Make some kind of stand to hold the pyramid upside-down – we cut some triangular holes in a cardboard box.

 

Seal around string
Seal around string to prevent leaks.
Mold in stand
Mold fits in support made from cardboard box.

 

 

 

 

 

 

Mix epoxy
Mix two part epoxy resin and hardener.

Mix the two parts of the epoxy glue, regular or quick-set. Pour epoxy into the pyramid mold, making sure to fill all spaces under and around the knot. Use just enough epoxy to cover the knot, with a little bit extra to cover and seal the piezo element. The epoxy should definitely be below the line marking the 2 inch edges.

Fill around and under knot
Make sure epoxy fills space under and beside knot.


Insert the piezo element into the epoxy. As the epoxy hardens, you may need to gently push the element back down to make sure it is completely covered.

Insert piezo element
Insert piezo element into epoxy.
Keep element covered in epoxy
Make sure piezo element is completely immersed in epoxy.


When the epoxy hardens, trim the excess cardboard, which should be inside the line marking the 2 inch (5cm) edges. Allow the epoxy to harden completely before testing in an inbindi – even quick-set epoxy should be left for 24 hours.

After epoxy hardens
Wait for epoxy to harden.
Trim excess cardboard
Trim excess cardboard.

 

 

 

 

Finished string-pickup
Finished string-pickup.

We have a few other tricks for making genuine Walley Electric Inbindi string-pickups, but yours should sound surprisingly good – even compared to other electric instruments. Obviously, starting with the best possible materials helps, but the best way to improve on the sound is to look for a bigger, badder bass amp and speakers. This is an electric instrument, so if you start with a clean tone, the amp and ‘effects boxes’ become the most important factors to your sound.

Making an Earth-board

Start with a board about 16 inches long, 5 inches wide and at least 1 inch thick (40cm x 12cm x 2.5cm.) A shorter board is definitely possible, but gives less leverage for your foot, which can be tiring. A thickness of greater than 1 inch is better because it gives some room for error during carving, but much thicker may mean your foot is further off the floor, which is less comfortable.

Decide where you will locate the pickup box. The first consideration is the location of the pickup hole – it should be near the center of the earth-board, but can be shifted a bit to avoid weak spots or take advantage of character features of the wood. Keep in mind that you will need room for your foot on one side, and one or more dimples 5 to 9 inches (13 to 23 cm) away on the other side of the pickup hole.

The next consideration is the phone jack socket. Its design will determine how thick the side wall of the pickup box must be for proper mounting. Don’t forget that the finish you use may contribute to this thickness.

You may want to look for a phone jack socket with a long barrel so the pickup box can be carved further from the side of the board. While checking out sockets, consider whether your board will be thick enough – not only do you need room for the socket, but you need a bit of extra maneuvering room during installation, and you don’t want any ‘hot’ electrical parts to touch the metal foil which may be installed on the inside surface of the pickup box.

Consider where the patch cord will be in relation to your foot. You will want to reduce or eliminate the chance of accidentally stepping on the cord and damaging it or the socket. You may want to consider which side you will be playing from, but it’s also nice to allow for other player’s who may stand on the opposite side.

We use a standard electrical cover plate to close in the pickup box. Its size, and the location of its screws restrict the relative positions of the pickup and the socket. Read ahead, mark the board where major parts will be (pickup hole, pickup cavity, socket, pickup box, dimples and space for the player’s foot), and check everything twice before carving.

Pickup Box

Place the electric cover plate near the center of the board and about 1/4 inch (6mm) from the side.
Trace around the plate to mark the area to carve out to the thickness of the cover plate.
You may also want to carve a notch on one side or end so you can get a finger under the cover plate to lift it out.

Trace around cover plate
Tracing of cover plate
Optional notch.

If the cover plate is too close to the side then the lip around the plate and the side wall of the pickup box will be thin and weak. If the pickup box wall is too thick then you may not be able to install the phone jack socket.

 

Cover plate sunk into board to be level with surface
The cover plate should be level with (or slightly below) the earth-board.

 

Mark screw holes and reference pyramid
Mark where the pickup cavity will go (leaving space for cover plate screws).

Check that the cover plate is level with, or slightly below, the bottom surface of the earth-board. Mark where the cover plate’s screw holes will be. Leaving space around the holes, place and trace the pickup pyramid as shown.

Carve a cavity to fit the pickup pyramid. A small guide hole drilled at the center of the triangle may help.
Sides should be flat, the three sides should meet at the center guide hole, and the corners should all be right angles.

Drill guide hole
Drill a guide hole.

The pickup pyramid should fit comfortably in the finished pickup cavity, with extra room if possible. Mark and carve out another cavity, the ‘pickup box’, for the phone jack socket, wires and connectors. Leave a strong wall between the pyramid and the pickup box.

 

 

Reference pyramid in cavity
Pickup (or mock-up pyramid of same size) should fit in hole.
Mark pickup box cavity for electronics
Mark other space to be carved, with enough room for socket without weakening pickup cavity.


Drill a hole for the phone jack socket. Ensure the side wall is thin enough to fit the socket, but not so thin that the side wall is weak. Careful sanding may be the best way to achieve this.

Completed pickup box
Pickup box carving is done, hole for socket has been drilled.
Pickup box with electronics parts
Need enough room for socket, pickup, a few wires and a terminals for joining wires.

 

 

 

 

 

 

Covered pickup box
Finished pickup box with cover plate on.

Drill holes for the cover plate screws. You may wish to insert plastic ‘anchors’ for the screws, the kind used with drywall – they can be replaced later on so you don’t have to worry about stripping the threads in the bare wood.

Top Surface

Earthboard with 2 dimples
Custom inbindi earth-board #026′

Shape, carve and decorate the top surface of the earth-board anyway you like. You need a place where you can comfortably place your foot to hold the board down, and a ‘dimple’ where the point of the staff will rest. A dimple is simply a depression that fits the point of the staff, with a felt pad at the bottom. As long as the staff can rock back and forth without slipping side-ways, the exact design of the dimple is not critical.

The dimple should be 5 to 9 inches (12 to 25 cm) away from the pickup hole, opposite from where the player’s foot will be. The exact distance is a matter of personal preference. A smaller distance means more leverage and less work, but increases the chances of the vibrating string hitting the staff and may limit the musical range you can get out of a stretchy string. The simplest approach is to make 2 or 3 dimples at various distances from the pickup hole so the player has freedom of choice.

Making a Staff

Bamboo, dowel and driftwood staffs
Bamboo, dowel and driftwood staffs.

One-piece

The staff is the most visible part of the instrument. It should tell a story about the roots and spirit of the instrument, as well as your own personal taste. The staff needs to be strong, with a diameter of 1 to 3 inches (25mm to 75mm).

A broom handle or straight dowel may be all you need to start. Hopefully you have more elaborate long-term plans, you can test the earth-board and pickup, and start learning to play with a simple dowel.

We look for a staff with character – a few kinks, bends or knots. With a bent staff, check that it will not get in the way of the vibrating string, and make sure it is not too weak (snapping it now is far better than snapping it later).

The staff should be about 5 or 7 feet (1.5m to 2m) long. Exact length is a matter of personal preference – the height of the player is a major consideration.

If you are planning on cutting the staff into two pieces, you may want to do it now. Like a pool cue, this makes the instrument easier to carry around town. Doing this is tricky, so if you aren’t sure how to put the pieces back together again without weakening the staff, then this in NOT recommended.

Bridge hole
Bridge hole

Decide where the string should be connected to the staff. You need a comfortable handle just above the connection point (i.e., where you will drill the bridge hole). Check again that the string will clear the staff when you are done.

Cross section of bridge and knot hole
Cross section of bridge and knot hole.

Drill a 1/2 inch (12mm) hole most of the way through the staff, stopping about 1/4 inch (6mm) from going right through. Drill the rest of the way through with a 1/4 inch (6mm) bit. The idea is to provide space for a knot while leaving enough wood to hold the string securely under tension.

Larger knot hole on other side
Larger knot hole on other side

Drilling a small hole all the way through is easier, but causes a problem. Consider the section of string going through the staff. During play when you change tension, this small section will stretch along with the rest of the string and may bind at the bridge point causing audible pops. The solution is to keep this section of string as short as possible.

Sharpen the bottom end of the staff, like a giant pencil (dull the point a little).

Finishing Touches

Carve, decorate, paint, stain and finish the staff and earth-board as you like.

Electrical shielding

Pickup box with metal tape lining
Finished pickup box with metal foil lining

We’ll call this next step “optional”, but it is very highly recommended. The pickup box should be “electrically shielded”. Without shielding, any exposed wire will act as an antenna for stray signals which may be audible after amplification. Signals may include anything from a nearby radio station to the ‘hum’ of household A/C wiring.

The solution is to stick metal tape or glue metal foil all over the internal surfaces of the pickup box and underside of the electrical cover plate. All the pieces of tape or foil must make good electrical contact with each other, including the cover plate when it is screwed on.

Your work does not have to be pretty, but if using tape make sure the glue on the tape is not acting as an insulator – fold over some edges of the tape so there is bare metal against bare metal, connecting every piece of foil to every other piece.

Finally, the metal should be connected to ground – it must make good contact with the outside of the phone jack socket barrel (or connect a wire from the socket’s ground connection to the metal).

Most of the photos here show a pickup box without the shielding (the photos are clearer without the shiny metal). Ultimately, you won’t know how much of a problem the stray signals will be until you get on stage and it is too late to fix.

Electrical connections
Electrical connections


Solder connecting wires to phone jack socket. We use screw-type terminal connectors to make the final connections to the string-pickup wires, but any form of semi-permanent connection will do. Install the phone jack socket.

 

Next: String