Added Jan 19 2011: you may also be interested in reading Ian Clothier's tips on Building Kalimbas.
Ever since I started selling spring steel for kalimba tines, people have been eating it up like candy. I realize that I am in a position to provide some guidance as to how to make tines from the spring steel and how to make kalimbas using the spring steel tines—even though I am not the expert that some of you are, or will become.
When you get the spring steel in the mail, consider it to be under pressure. Take it out of the box cautiously, as it is wrapped up in a long section, ready to spring and whip you. In addition, the cut ends may be sharp. The spring steel will be held in a circle either by wrapping the ends around the rest of the steel (much as a guitar string is held in a small circle), or by tape.
You will need to cut the tine material to length. See the section on tine lengths below to learn how long your tines need to be. I bought a heavy pair of pliers, and I grasp the spring steel with the pliers and bend the tine material at a right angle, back and forth, until the metal fatigues. You may have a better way.
The sharp ends of the tine - both the playing tip and the far end - need to be smoothed. An efficient way to do this is to get a grinder from your local hardware or tool store. Most grinders have a rough stone and a smooth stone. I think mine are 36 and 80 (the larger number being the finer grit in the grinding wheel). Use the coarse grind to shape the tine like a U, and use the fine grind to smooth it out.
The tine will get hot when you grind it, be careful. Also, be careful holding onto the tine. The grinder could pull the tine out of your hand. Wear eye protection. There are flying sparks. While grinders can be used safely, this is not the kind of thing young kids should be doing. I think my son started using the grinder at age 14 under adult supervision. Use your own judgement.
After the tines are smoothed, select the smoother or better shaped of the two tips to be the playing end. With the pliers, grasp the last 3 or 4 mm of the playing end and bend slightly down - this will make the playing smoother.
Of course, you are free to experiment with different methods. I don't know anything about plating, but at this stage you could do some electrolytic plating to get nicely finished tines. You could also paint. I recommend enamel paint.
We draw a distinction between two different meanings of tine length. First, the full tine length includes both the vibrating end of the tine plus the 5cm or so that you need to attach the tine to the kalimba. The vibrating tine length is the distance from the vibrating tip of the tine to the metal bridge. If you are cutting steel, you need to know the full tine length. If you are studying the physics of vibrating tines, you will be more interested in the vibrating tine length.
For a given type of spring steel, the longer the vibrating length of tine, the lower the pitch, or the shorter the vibrating length of tine, the higher the pitch. There is a specific relationship between the vibrating length and the pitch: when you increase the vibrating length of the tine by a factor of 1.41, the frequency of vibration is cut in half, or the pitch decreases by an octave. Conversely, cutting the length by a factor of 0.71 will increase the frequency by a factor of 2, and the pitch goes up an octave.
This behavior only holds when comparing tines of same thickness and same springiness. Kalimba Magic sells tines of three different types - 3mm wide, 5mm wide stiff, and 5mm wide floppy. The table below indicates the vibrating length, in cm, of tines of the three different types which you need to get various pitches. For pitches not listed, you can interpolate or, better yet, use the equation relating frequency to the vibrating length of the tine.Vibrating Tine Length [cm] for various notes and tine materials. Using the data in this table, you can verify the octave scaling relationship mentioned above.
|196 Hz||294 Hz||392 Hz||587 Hz||784 Hz||1175 Hz||1568 Hz|
Adding 5cm to get the full length (your additive factor will depend on the details of how you attach the kalimba tines to your kalimba, but 5mm is similar to the length which is added to the Treble kalimba's tines).Full Tine Length [cm] for various notes and tine materials.
|147 Hz||196 Hz||294 Hz||392 Hz||587 Hz||784 Hz||1175 Hz||1568 Hz|
Note that you may need to cut 2-5 mm extra in tine material that will be lost in the cutting and smoothing process. You will discover how much extra you need after you've made a few tines. Also, be sure to adjust this table for the actual length you need to fasten the tine to the kalimba.
For comparison sake, the 5mm width is similar to the width of the Alto kalimba. The Treble tines are 4mm in width, and the 3mm width of tine material we sell is what is used on the Goshen kalimba. Also, the Alto has a range of G3 to G5, so D3 is lower than the Alto's lowest note and G6 is an octave higher than the Alto's highest note. The Alto kalimba tine stiffness is between the 5mm stiff and 5mm floppy tine material.
Another note: if your kalimba's face wood is thick, it can support any of the kalimba tines. If your kalimba face wood is thin (1/8 or 3/16 inch wood), it will absorb the vibrations from the 5mm stiff tines, so you should look into getting either 3mm tines or 5mm floppy tines.
By the way, the equation that describes the vibrational frequency is this:
frequency = A/L^2
You can easily find a chart to map the frequency into a pitch (e.g., 440 Hz = A4). Here is one. In the equation above, L is the vibrating tine length, and A is a constant of proportionality, which depends upon the spring steel density and strength. In other words, different types of spring steel will have different A constants. Doubling the vibrating length will increase the frequency by a factor of 4, dropping it by two octaves. Small changes in tine length correspond to big changes in frequency.
If you are an expert box maker, you will probably make beautiful box kalimbas. But if you are not, you might want a shortcut. Nature provides us with a fantastic resonator box: the gourd. Gourds do take time to process, but this is still a lot easier than making a box. They have a great rustic look as well.
Some time back, we ran a series of tips on using gourds for an external resonator, or for using gourds as the body of your homemade kalimba. These tips are not exactly a step by step guide to making your own gourd kalimbas, but they should provide you with enough information for you to find your own path and make your own kalimbas!
Several folks have been making kalimbas with the new tine material. These people are excited and proud of their creations, and they are inspiring other people to build and play kalimbas, which is a great thing. To honor the best of these individuals' creations, I am going to start a new contest. The contest will have two categories:
OK, I'm trusting that you won't just pull out your Hugh Tracey or Sansula and play it on the sly! (But, of course, if you do, I could very well recognize those familiar tines.)
Prizes: $50 gift certificate to Kalimba Magic for the best looking and best sounding kalimbas.
We'll give you some time to work on your kalimbas. Let's have a deadline of October 20, 2009, and we'll feature the winners in the November Kalimba Magic Newsletter.
To enter the kalimba-making contest, just contact me.