Kalimba With Love

About 4 months ago I met a charming Filipina with love for music, she got my knees weak singing me Sunday Morning. Christmas was closing in, it's a no-brainer that any self-respecting man would want to slay his crush with a beautiful Christmas present and so was the inception of this. welcome everyone, to another love-inspired Instructables.

I made her a Mbira, an African-origin musical instrument that's relatively easy to build, setup and play. There are of course a lot of other Instructables and tutorials on how to build a Mbira aka Kalimba aka thumb piano in a much simpler way, but I get my daily-fix by wrecking my brain over building lovely little things.

If you want to get straight to the build-relevant information and skip my engineerings stories, hop through the italicized text in steps 2,3,4,5 and 6.

Research: In a lot of the DIYs, things are just put together without paying much or any attention to how the different parts would affect the performance of the instrument and surprisingly all of them seemed to sound satisfyingly great no matter how they were built, like the Krazy Kalimba which uses popsicle sticks for tines that I would never have thought could work, Kalimba by ravenking that uses kebab skewers; KEBAB SKEWERS!! Also my favorite, The Minty Kalimba built on an Altoids tin.

However, there are a few observations I noted that possibly made me more decisive during the design phase.

• Although it looks like a handheld instrument, the more-avid Kalimba enthusiasts prefer to place the instrument on a hard, flat surface to minimise resonance damping and produce consistent notes.
• Referring to the previous point, it's best to use a hard, dry wood that resonates well. Especially, tonewoods if you have access to them.
• Customizing the tine spacing, arrangement and the size of the resonator box that suits you. I can't comfortably play The Minty Kalimba for sure or possibly the ones with a very dense set of tines considering I have no long nails or slender fingers.
• If you're planning to use the instrument with an amplifier, make sure your pickups are located in prime resonance zones to avoid odd-sounding blunt notes -- more on this further down.

Design: I'm a bit fanatical of the idea that less is more when it comes to design philosophy and I did my best to not reflect visual or functional complexity throughout the process.

For the 3D modelling, I pretty much just made blank foam shapes of the resonator box and once I fine-tuned the overall size and ergonomics in the crude foam blank, I recreate the same dimensional outline in CAD, generate a 3D model and then add all the other parts on to it.

Materials: I chose wood for the resonator box mostly because of the aesthetics, the ease of working and also for its acoustic properties.

The tines are made of spring steel stiffeners found in windscreen wiper blades.

The tensioners are chrome-plated mild-steel rods.

I have used water-based wood glue to put most of the parts together. An epoxy-based adhesive is used in a few places to add extra strength and a synthetic varnish coat at the end to seal off everything from moisture and dirt.

All of the 2D and 3D modeling work was done using Solidworks as per the design principles mentioned in the previous step.

I had some 3mm Balsa ply and 7mm Pine ply sheets laying around, so I decided to make the resonator box out of it. The 3mm Balsa ply made up for the deck and the base plate, the 7mm Pine ply made up for the bulk of the structure.

I also decided to electrify my Kalimba and the easiest, most effective way I could find is to use piezo buzzer disks. The electronic circuit itself is very simple, but apparently, the placement of the piezo pickup disks can sort of affect the way your Kalimba sounds through an amplifier. The most obvious place is right below the tines, but my design wouldn't allow for such a placement. What I did next could be a controversial theory and a complete overkill, so I performed an analysis on Solidworks Simulation to find out the region of maximum amplitude on the deck for a particular set of frequencies the instrument shall produce and that way I localized the placement of my piezo pickups.

Things you'll need:

1. 3mm Plywood
   
2. 7mm Plywood
3. Flat spring steel strip or used windscreen wiper blades
4. 5x80 metal rod (diameter x length) [1 Nos]
5. 3x70 metal rod [2 Nos]
6. M3x25 screw [2 Nos]
7. M3 nuts [2 Nos]
8. M3x10 screws [8 Nos]
9. M3x15 metal spacers [4 Nos]
10. Piezo disks [2 Nos]
11. 6.3mm Mono socket [1 Nos]
12. Electrical wire

• Basic hand tools like screwdrivers and pliers
• Access to a non-metal laser cutter (80W to 100W) or a CNC wood router.

All dimensions mentioned in millimeters (Metric).

Fabrication is one of the tricky parts of this build. The design tolerances are set to laser cutting requirements. However, you will have to play around with your laser cutter's power and speed settings to ensure a high tolerance cuts and to not burn off the edges too much.

I suggest you do a few test cuts before you get down to cutting the Kalimba parts.

The settings I used:

3mm Balsa Ply Engraving: Power 35 Watts, Speed 350 mm/s

3mm Balsa Ply Cut: Power 50 Watts, Speed 18 mm/s

7mm Pine Ply Cut: Power 75 Watts, Speed 8 mm/s

The assembly part is pretty straight-forward and the easiest step. Throw in some glue, screws, nuts and just clamp it all down for a few hours.

It was so fast and short lasting that I almost forgot to take intermittent pictures, so please refer to the exploded CAD views for help in assembly.

This was relatively the most difficult part for me because I had never tuned a musical instrument before and so I had to go about some basics of music before I could make the Kalimba sound right.

After a whole bunch of YouTube videos, reading blog posts and help from a few friends, I got the Pano Tuner app on my phone and began the slow tuning process. I still can't be certain my kalimba sounds like it's supposed to, but this was the best I could do.

There are a lot of videos on how to tune a 9-tone Kalimba, But I'll link the ones that I found helpful,

New Tuning for Sansula Kalimba

How to Fine Tune A Kalimba or Thumb Piano

I made a hot-wire cut foam case for my Kalimba because it was flying across oceans and I didn't want a rough bump to knock its tines out.

She finally received the Kalimba and I can be certain she loves it! I can't want to listen to her play me a piece!

Also, Valentines' day is around the corner and I made Love Spark a couple years ago for my then you know who. Check it out, you can crank one out in a couple days really!

Happy making!