Latabonkers !

I call these instruments latabonkers because you bonk them with a drum stick and I made the first ones out of tin cans ("latas" in spanish). Basically, they are springs attached to an amplifying surface such as the bottom of a tin can, or a flat cafeteria tray.

Inspirational in their development were two things; the kalimba, an African thumb piano instrument that has vibrating metal units attached to an amplifying wooden sound board, and a sound making toy I once saw that had a long spring attached to a flat surface set at the end of a piece of PVC pipe. When shaken, it sounded like thunder.

I make my own springs, either by hand with pliers, or with a special winding tool I made. They are made out of regular galvanized wire from the hardware store, usually mounted to the base with nuts and bolts. A simple latabonker using a discarded tuna fish can costs about 15 cents to make, including the nut and bolt. The plastic cafeteria trays (Sam's Club) add another few dollars to the cost, but they are still cheap for the sound they make.

Check out the audio files throughout the instructable to hear what they sound like. There is lots of variety to the sounds. Due to the fact that many of the sounds linger and overlap, you can get a pretty full sounding percussion section with just one person playing.

Even a straight piece of wire is springy and can vibrate when struck. Every time you make a change to it, it will sound differently. Longer usually means a lower note, and shorter means a higher note. It is easier to cut off wire than it is to weld it back on, so the tuning process usually means snipping off the tips of the wires until the desired note is reached.

Wires that have been wound into helical springs can be stretched to lower the tone, or compressed into a tighter winding configuration with needle nose pliers to raise tones.

A helical spring sounds about the same when struck anywhere on the spring. Some straight wires can be given elbow bends to create straight segments of different lengths in the same wire. There will be different notes for each of the straight segments. The tuning process can be complicated, but that's what makes it keep on being fun.

You can see some of the various spring shape families in the pictures. Long helical springs held down at both ends, zig-zag springs, springs with helical winding near their bases, or out at their tips are just some of the variations possible.

The sounds available in a set of latabonkers flavor the music one can make with it. They are very good at doing music with that flavor, but if you want another flavor for the music, you have to make another set of latabonkers. As you can see, my collection of latabonkers has grown quite a bit.

The springs are usually mounted to the amplifying surface with a nut and bolt. I prefer the bolts and square locking nuts used on louver window cranks. The sharp corners of the square nuts are bent down and lock into the base material.

My system for winding helical springs is pretty simple. The wire wraps around a rod, pipe, or tapered mandrel (my favorite because the springs pop off easier when done). I use 1/4 inch rebar for my smallest diameter springs. The rod goes through a guide hole in a piece of 2 X 4 held in a vise. The tip of the rebar, or pipe has a channel cut into it that the tip of the wire locks into to start the winding. A roofing tack near the hole is a guide for the wire.

When finished, the spring is supposed to just slide off the rod, but it usually takes some fighting to get it off, because the wire can get stuck on rust pits or other irregularities in the rod. My tapered ring mandrel solves that problem but is limited to making tapered springs.

At one end of the spring, you have to take pliers and make a sort of horse shoe bend that the mounting bolt can hold onto.

Avoid situations where metal can vibrate against metal in loose connections, or you will get unwanted buzzing sounds. Mount springs with enough distance between them that they won't bang into each other.

Different diameter wires have different sound qualities.

Tuna cans make good bases for latabonkers. My hand is large enough to cover the can's opening and create a wah-wah effect when it is opened and closed. Many people have hands that are too small to do this. You can sometimes find smaller cans in the trash that will fit smaller hands. I prefer iron cans, but aluminum cans can also work.

Drill a hole in the center of the can and bolt the spring to the can. Hit it with a stick and off you go. These are entry level latabonkers.

Click on the audio files to hear how they sound.

Larger cans have larger bottom surfaces and more space to mount more springs. The result is a more complex, multi-tone instrument. I eat a lot of peanuts from Sam's Club, and these are the cans they come in.

Since the mouth of the can is too large to cover with my hand to create a wah-wah effect, I get a similar tonal warp by pulling down on one of the springs with my thumb, which warps the bottom of the can and distorts the sound. Pulling down on that spring affects the sound of all the springs since they all are amplified through contact with the same flat can surface.

I hold the can on my hip with one hand and bend the wah-wah wire to reach that thumb for easy wah-wah control.

Click on the audio files to hear how they sound.

Trying to get more and more sounds available to me while I play, I came up with a way to mount two parallel pieces of wood on folding keyboard stands. The wood is held to the stand with rubber bands. Each stand supports three trays and each tray has lots of sounds. The trays are buffered from unwanted vibrations against the wood by rubber pads. Flat head crews in the wood hold the edges of the trays against the rubber pads. By pushing in and warping the tray a little, it can be replaced without having to remove the screws.

When a plastic cafeteria tray is used as the amplifying base, the sounds tend to be more like wooden instruments. Metal bases sound more metallic.

Click on the audio files to hear how they sound.

If you strike a metal spring with a metal drumstick, the sound is different from what a wooden stick makes. There are more high overtones, for one thing. My favorite drumsticks are made of wood "pincho" (shish-kebab) sticks wrapped with yarn and either hot melt glue, or silicone rubber. The silicone is softer than the hot melt glue, which is in turn softer than wood, or metal. Contact with softer materials tends to cut out some of the higher overtones. Any sound can have its uses in music but I find the ones with softer drum sticks to be a little sweeter to my ear.