Introduction: Instant Thumb Piano: How to Make a Set Screw Lamellaphone

Picture of Instant Thumb Piano: How to Make a Set Screw Lamellaphone

This is a method to quickly and easily make a musical instrument capable of melodic percussion and noise experimentation.

The thumb piano, known as a kalimba or mbira and by many other names, is a lamellaphone that uses plucked prongs called tongues, keys or tines to generate acoustic vibrations. The length of the tine determines the pitch.

Generally, the thumb piano uses some kind of mechanism to create a great deal of pressure to anchor the tines across 2 bridges which allows the free lengths of the tines room to vibrate. The tines are usually of the same material and gauge (thickness) to ensure consistency so the pressure is distributed equally holding everything in place and in tune.

The method shown here is simplified and wonderfully versatile. It allows the use of more fragile, delicate, and unusual materials for the body of the instrument, and it provides a way to use oddly shaped tines of different materials at the same time while permitting the tines to be swapped out and tuned with ease.

There are interesting possibilities here: a simple armature or jig that becomes a tool with which to investigate the sound that different materials make - how they vibrate, how they resonate and how different combinations of factors can change the sound quality.

Experiment and explore and find configurations that work for you.

More photos:
Flickr set

Video link in Step 6.

Step 1: The Grounding Bar

Picture of The Grounding Bar

The grounding bar is an item used by electricians to ground house circuit wires. It comes in a variety of lengths and can be found in the electrical section of most local hardware stores or builder/contractor supply centers.
The bar shown is about 4 1/2 inches long and 1/2 inch in width.
The 3 empty slots are drilled all the way through, this is where fasteners can be used to attach the bar to something.

Step 2: Fasten the Grounding Bar to a Surface

Picture of Fasten the Grounding Bar to a Surface

All you need to do is make 3 holes with a hand drill into the surface you want to become the body of the instrument.
The screws shown in the photo are hex head 10-32 machine screws. They are used in the thumb piano shown in Step 9 by using a tap to thread the holes. Otherwise, these need washers and nuts to tighten for anchoring the grounding bar, or instead of washers, some kind of plate for the nut to press against. Smaller and different types of machine screws could be used adding washers and maybe lock washers as needed.

If you are going to mount the bar on wood or thin metal like a tin can, then you may only need a hammer and nail to make the 3 holes.

With wood, just use wood screws or something similar. Nails alone might possibly do the job with a bit of wood glue - start the holes with a nail, add a bit of glue to the holes before driving them firmly.

Heavy duty epoxy, riveting, welding or even slotting a surface with a milling machine or router are some other ways to anchor the bar.

Step 3: Shims Might Be Necessary

Picture of Shims Might Be Necessary

The tines need room to vibrate, so depending on the type of surface chosen and the way the bar is mounted, it may be necessary to lift the grounding bar up off the instrument body using a shim. This just requires 3 more holes using the grounding bar as template.

The photo shows a steel bar and a wood square dowel for shims. Plastic, clay, bondo, rock hard water putty or other materials could be used.

The shims in the photo are trimmed and clean but they could be made of scraps, rough and irregular of edge, as long as the thickness is consistent.

Metal tines can be bent away from the instrument to give more vibration room (action), the more action the easier it will be to play.

Later steps show examples where no shims are needed.

Step 4: The Grounding Bar Open on a Shim

Picture of The Grounding Bar Open on a Shim

The grounding bar provides a set screw method to hold tines.
The photo shows the bar on a shim with the screw slots opened.
You need a regular flat blade standard tip screwdriver or a driver with a Robertson bit.

Step 5: Adding a Tine

Picture of Adding a Tine

Inserting a tine.
The tine can be anything that will vibrate and can fit the hole.
This photo shows a blue tempered spring steel tine.

Crank the screw down tight to anchor the tine.
This grounding bar can hold 12 tines.

Step 6: Body and Tine

Picture of Body and Tine
The grounding bar mounted on a small wood crate from a thrift store.
This demonstrates what is great about this method - you can use tines with a variety of shapes, sizes and materials at the same time.

Tines shown in the photo below the video from left to right:
blue tempered spring steel
street sweeper bristle
unknown steel lattice debris
electrician's snake
knitting needle
street sweeper bristle
bicycle spoke
spring steel
umbrella rib
plastic hobby/craft brush
plain steel wire - the end splayed by hammering

There is a video of this thumb piano being played.

Very roughly tuned and I used a guitar tuner pickup to run signal into a delay and guitar amp. Normally I would put the pickup closer to the bar but I was using a rubber band to hold it in place so where I placed it suited the size of the rubber band. The audio is just what the little point & shoot camera microphone was able to catch.

Step 7: No Shim Needed

Picture of No Shim Needed

By using something for the body with a lip or edge, like a wood box or desk drawer, the tines are free to vibrate over the receptacle so a shim is not necessary.

Step 8: Cigar Box Lid

Picture of Cigar Box Lid

The inside of a cigar box lid can provide a shallow receptacle that fits well in the hands. Again, no shim necessary.

The tines shown in the photo are bamboo teriyaki skewers.

Step 9: Other Emphases

Picture of Other Emphases

This is an example of the grounding bar used on unusual materials but in a conventional way.
The tines are spring steel and uniform across the span.

The body is aluminum, a 3/4 inch thick block, and there is an aluminum shim.

I wanted to make something sleek that looks machined but I really just used a cheap, much abused drill press. I used a tap to thread the anchor screw holes, putting the tap in the drill press and turning the chuck by hand.

Surprisingly, the thing is so heavy that a hollow door on sawhorses makes a good resonator for the instrument.


Picture of TRY THINGS
Here is a conceptual conglomerate.
The photo near the bottom of the page shows a zither from a thrift store mounted with the grounding bar kalimba which holds uniform spring steel tines. The bar is sitting on a steel shim and the tines are slightly bent to get above the zither strings.

Example of instrument using plastic swizzle sticks for tines

Soundcloud page

New 2008 all thumb piano audio album:
Lamellaphone -

For more of my thumb piano experiments:
thumb pianos by RP Collier

thumb piano demos:
faux fur demo
chopping block lamellaphone
more mostly thumb piano videos:
videos by RP Collier

Example for tapping, scraping and bowing:


Greg Bossert of also provides a great example of using mallets or drumsticks to tap long tines in the grounding bar which results in good bass tones:
Check out the sound sample:


CHAPSGENSTORE (author)2015-01-01

These are three of the several kalimbas I've built from cigar boxes. Currently working on one using bamboo skewers and a small metal tray for the sound board. The metal tines have the superior tone but I like the ones I've made using popsicle sticks as well.

tahoma (author)CHAPSGENSTORE2017-10-19

The cigar box with popsicles looks fun and accessible to make. Do you have the instructions? or advice?

yapruder (author)2016-05-21

Just released an album of solo thumb piano music.
A collection of extended loops, sketches and songs selected from 15 years of recordings of experimental lamellaphones I build.

Album title: Trundlebox

Now at Bandcamp, and soon at iTunes, CDBaby, etc.

CRAZEDCLAM made it! (author)2016-03-01

Mine worked. It plays a G scale.

yapruder made it! (author)CRAZEDCLAM2016-03-01

Glad you liked the result. Here is one I made with the tension I mentioned. The tines are so fat they would not even fit into the ground bar slots without a bunch of filing and grinding.

CRAZEDCLAM (author)2016-02-16 You even used the same words, or did they copy you?

yapruder (author)CRAZEDCLAM2016-02-16

That was me. There was also a version for Craft Magazine if I recall correctly.

CRAZEDCLAM (author)yapruder2016-02-17

oh, didn't mean to sound rude, it's really cool, I'm making one right now with rake ends for the tines!

yapruder (author)CRAZEDCLAM2016-02-17

Rake tines are great. They work best I think when you put real tension on them. The set screw method really limits the pressure to a single screw (per tine) which is not that much.

TinyBotics (author)2014-01-17

1) Is it possible to make an "alto" kalimba tuned for the C3-C4 range? Do you know the relative sizes for the box and the tines? (I know exact tuning would be up to me per tine).
2) Do you think it would be okay to use an old metal rake for the tines for this tuning? I see them referenced in some comments. Have you ever tried tines from a wooden rake?!

yapruder (author)TinyBotics2014-01-17

1. Surely possible. Don't know the sizes, maybe 2" length past the bridge for C3 using a 3/16th" tine. The box used by Hugh Tracey kalimbas is something like 9" x 5" with a 2" depth. I would suggest getting a tuner or a tuner app and experiment.

2. I'm not sure, all you can do is try, depends on the thickness as well as length. There are tuning tricks such as grinding under the tip that can help. I have not tried a wooden rake tine, should be similar to a teriyaki skewer. The sound is much more percussive -- you get more sound tone versatility by using a contact mic in that situation.

TinyBotics (author)yapruder2014-01-17

Thank you for writing!!!

I just found a pre-made hinged box from a craft store that is 8.5 x 5.5 x 2 with 1/4" walls. Think maybe that is big enough then to give a whirl? It is at least in the ball park. I'll have to figure out where to place the bridge and make a hole, etc. For tuning, I've been using the gStrings app on my Android phone and Spectrum Analyzer on my iPad to try to tune some homemade instruments.

We won't have the opportunity to use a contact mic in this situation. So, we are probably better to go with the metal tines but can experiment. I just checked the wooden rake tines and they appear to be bamboo.

Of all the tine materials you've tried (looks like a lot!) what is your favorite?

yapruder (author)TinyBotics2014-01-17

The type of wood and solidity of the build will determine how the box handles vibrations.
My favorite tine for a medium size thumb piano with no contact mic is 3/16th width and .032 gauge spring steel.

Oledoug (author)2012-05-21

One of the best tines I've used come from Windshield wipers.....Check with you local repair shop and have the save you the stainless strips from the old wipers....The work great and are easily found.....

marktreefrog (author)2012-01-23

by gluing down the grounding bar and finding more screws I was able to use all of the ports. So no gaps. I used JB weld for this.

yapruder (author)marktreefrog2012-01-23

Good, thanks for posting.

The way I like to do it is to use a tap to thread the bottom of several of the holes and then screw in place from underneath to free up all the horizontal holes.

Another way is to use speed nuts which are flat, square and springy. You find the size that fits in the hole, screw in from the top down past the horizontal hole and use a hex nut to again anchor from underneath. Then the top of the anchor screw becomes the floor of the set screw.

I'm sure there are other ways people will come up with as they experiment. This instructable was trying to keep things as simple as possible.

marktreefrog (author)yapruder2012-01-23

I like that idea. I will have to try that. Another fun addition is a piezo pickup and jack. this picture shows every thing tape in place temporarily before glue and soldering for a more permanent fix.

blacksmith_tb (author)2007-10-08

What's the source of the 'blue spring steel tines'? They look like a nice, uniform choice.

mmbutler (author)blacksmith_tb2009-07-21

A typical metal-tine grass rake will give you a lifetime supply of one width of blued spring steel tines, though they'll typically be overpainted some other color . :)

DublA (author)mmbutler2011-11-19

Of course!! A rake! You can't imagine the time I spent wandering around Home Depot aimlessly trying to find something approaching spring steel.

yapruder (author)blacksmith_tb2007-10-08

I get the blue tempered spring steel from a local Machinery & Tool Steel Co., a big industrial distributor. They do have a minimum, but even so I think it is only 10ft. rpc

insanepotato (author)2009-04-09

I'm in Australia, would Bunnings have "grounding bars"? I've never seen or heard of them in my life.
I'm planning on using cheap Asian tongue scrapers as tines, since its possible to find some that are almost identical to that blue steel (just not blue), although I'm not sure what I'll mount it on xD

thanks for sharing the idea btw =D

yapruder (author)insanepotato2009-04-10

I don't know Bunnings but as a home warehouse it ought to have some version of the grounding bar. Tongue scrapers as tines is a great idea. Probably interesting sounds and good hygiene!

Warlrosity (author)yapruder2009-07-18

It is more of a ... Hardware store! Massive,green,amazing! Btw nice work!

insanepotato (author)Warlrosity2009-07-18

turns out, they dont have them, so still no kalimba for me haha

yapruder (author)insanepotato2009-07-18

There is always the web option. A search for grounding bar or kit will give a bunch of results that you will have to refine for Australia or a firm that will ship there. Make sure you use a product photo to select from, in some cases "grounding bars" can actually be more like flat metal plates with holes rather than bars with set screws.

mmbutler (author)yapruder2009-07-21

In the Commonweath there's a tendency to use the word "earth" where Americans would use "ground". Insanepotato, you might try to use "earth bar" or "earthing bar" as search terms. Schneider Electric makes them, I think, but even if not, a bit of looking for "electrical supplies" in the phone directory should point you in the right direction. Rexel Electrical is one Aussie company name I have heard. Good luck!

wocket (author)mmbutler2010-08-29

i wonder if anyone actually ended up finding some in Australia? (author)wocket2011-10-22

Apologies for the late reply. Yes, I did - under the name "earth bars" or "neutral bars". I ordered a handful of brass ones from Metroid Electrical Products in Victoria, and they were in my mailbox the next day. Work well with bike spokes and street sweeper tines, but Australian designs often have a doubled row of holes for attaching the earth wire.

Explain what you want - after I explained it to their sales guy, he provided me with engineering drawings for a variation which isn't on the website.

Warlrosity (author)insanepotato2009-07-18

too bad

Make friends with an electrician who does rennovations a lot, the piece you want is inside a circuit box(panel). It is where we tie down the neutrals in USA we have 110-120 volts ac, not 200-210 v ac . There should be a strip inside the box that has a grounding strip. When we do a rennovation (say pullout a 60 amp or 100 amp house service, the box is garbage and sent to the scrap heap. I no longer do electric work, but people toss them out occassionally. I made a Kalimba with my kid so I will need to look around for one of these.

This is a great idea I never thought of!!! But where does one get better boingers, err reeds. Regular pulling snake is fine for about 8 notes that's it.



yapruder (author)spark master2010-09-27

>But where does one get better boingers, err reeds. Regular pulling snake is fine for about 8 notes that's it.<

Using a piezo pickup should help expand the range. There are some instructables and Youtube videos that describe how to build one.

spark master (author)yapruder2010-09-27

wow a hot wired kalimba , are the piezo's cheap?


yapruder (author)spark master2010-09-28

The most common diy uses a Radio Shack "buzzer", probably about 3 bucks. That piezo is thin and flimsy. Piezos come in many sizes and thicknesses. Search online for sources, they are generally low price but because of that there is often a minimum purchase maybe from 10 to 100. I had good luck with an electronics & science supplies liquidator, I think it was 12 for 5 bucks.

tankdo (author)2011-10-17

Well, first, good instructable! i have the same problem trying to find the "gorunding bar" because im in latin america and i didn´t knew the spanish name, that piece is also known as Terminal Bar or link bar conector, in this case, a 15 way Terminal Bar, i hope this help!

Para los amigos hispanohablantes: la pieza se consigue como Bloque De Terminal de metal o latón o Barra Terminal de latón, o Bloques de Tierra de 8 vías (o de las vías que sea dependiendo del nùmero de hoyos) está catalogado en la electrónica como accesorios de puesta a tierra, por eso en inglés lo llaman Grounding Bar.

Espero que les haya servido la informaciòn, realmente es un instrumento hermoso y vale la pena hacerlo!

rhysc (author)2010-10-19

Did anyone from Australia figure out where to buy ground bars? The closest thing I could find was this:

Dagless (author)rhysc2010-11-08

I'd try electrical suppliers/wholesalers such as Lawrence & Hanson or Rexel. I worked at a similar electrical supplier in New Zealand and we stocked these in varying lengths. We called them busbars (pronounced 'buzz bars'), so they're possibly called that in Australia too.

cheveux.boucles (author)2010-01-02

That was a great instructable - thanks!  I ended up using hammered-out bicycle spokes as the tines, and a cigar box as the resonating chamber, and it sounds great - especially with a contact microphone right under the bar.  Keep it up.

mistic (author)2009-08-31

made one years ago- I eventually drifted to stringed instruments- made a mini-zither- but found some minor problems such as boxes giving unusual strange resonances -unwanted discords ,etc. still it plays like a harp and goes nicely with my kalimba. {see my instr- Mini-zither}

amplex (author)2009-08-21

awesome sounds, i love the creative tines and the difference in tones you get from them, im definitely going to build one of these asap!!!!

agis68 (author)2009-03-05

Very cool..i will make one five stars...excellent project and well done

8bit (author)2009-02-17

Five stars! Excellent!

yapruder (author)2008-12-09

UPDATE: Here is a good example of using mallets or drumsticks to tap long tines resulting in great bass tones, check out the sound sample:

Courtesy of Greg Bossert of

Immrwrite (author)2008-10-12

This is awesome! I'm on my way to the hardware store right now! finally a use for all those small wooden boxes that tend to collect around me. Thank you very much for a great Instructable!

sarandi (author)2008-05-16

I was just thinking...I've seen tines like that somewhere - and then it hit me: Old windshield wiper blades have similar metal inserts! Thanks for the wonderful ideas - the grounding bar is genius. It could also be used to build a stringed instrument!

AndyGadget (author)2008-01-24

Cycle spokes make excellent keys. Mount them with the mushroom shaped bit pointing up and it's much easier on the thumbs if you're a nail-biter. Tune the thing to C Major (CDEFGABC...) if you want to play 'real' tunes on it, or to a minor pentatonic scale (e.g. ACDEGA...) and any 'improvisation' will sound harmonious. A software tuning aid is essential if your musical ear is anything like mine. The Mk2 version will have a thin wooden top as I suspect ply is not the best choice for a soundboard.

yapruder (author)AndyGadget2008-01-24

In the photo in step 6, the box has a cycle spoke mounted about 5 tines in from the right side. I used the other end from the shroom screwcap, the tip is flattened with a hammer. For delicate thumbs, you can coat the end of a tine in the dip coating stuff from hardware stores -- called plasti dip or similar. I made a kalimba using 1/8" Luan plywood with umbrella rib tines that sounds fairly good. The entire box was made of the Luan glued together though, not just the soundboard. Some configurations of materials will bleed off vibrations or dampen the sound. Quirky materials and unpredictable results means much room for experimentation.

aeray (author)2007-12-22

Just built one for my brother using the ground bar method, pegged black walnut for the box sides, dense, almost-instrument-grade spruce for the top and bottom, and tines from an old rake for the keys... total cost $6 for the ground bar. Looks good and those I have shown it to who don't have a tin ear like me say it sounds good too. Excellent idea.

mikecraghead (author)2007-12-07

Time to go ground-bar shopping, indeed!
And then... plug it in!

estevan (author)2007-10-24

i need some suggestions as to where i could get some decent tines. i went to a home depot and my options were severely limited and i was uncertain as to how to describe what i'm looking for in terms of tine material. Any places online i could order materials?

About This Instructable




Bio: RP Collier - artist, musician, writer
More by yapruder:Instant Thumb Piano: How to make a set screw lamellaphone
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