Introduction: Thumb Piano

Picture of Thumb Piano

I saw one of these somewhere a while back and always thought it would be fun to play with. A quick Google came up with several including the one in this picture. It's available online for about $33. I'm no kind of musician and I've never built a musical instrument before but this looks simple enough. I'd rather just make one.

Step 1: Materials:

Picture of Materials:

Looking at the image I found on google there is no reference to tell exact size but I'm not really worried about making it accurate. I'll guess it looks to be about 5" x 7" x 1".

For most of the parts I was looking for stuff I had sitting around. This is the parts list for what I ended up with.

(2) - 3/16" plywood - 5" x 7" for the top and bottom
(2) - 3/4" x 3/4" x 3' pine - 5" and (2) 7" for the frame
(2) - 1/4" dowel - 2-1/2" to support the keys
(1) - 3/8" aluminum rod - 4" to hold down the keys
(1) - 3 1/2" nail - cut to 3-1/4"
5/8" x 18 brads - optional
(2) - #6-32 x 1/4" T-nuts
(2) - #6-32 x 1" round head bolts
street sweeper bristles - enough to make 9 keys about 2-1/2" - 3-1/4" each.

I had to buy the T-nuts and bolts but the rest I was able to scrounge. The "keys" were made out of street sweeper bristles. They're easy to find if you get out and walk much, just keep an eye on the street.

Step 2: Cut Out the Wood Parts

Picture of Cut Out the Wood Parts

Cut two 5" x 7" plywood sheets for the top and bottom of the box and the 3/4" pine into 4 lengths at a 45 for the sides - 2 @ 5" and 2 @ 7". Glue and (optionally) nail the sides onto the bottom with small brads, then set it aside. I didn't mind using brads to hold the bottom together while it dried. They won't show much but you could just clamp it instead. Just be sure to set them in deep enough so they won't stick out and scratch things.

Step 3: Front Face

Picture of Front Face

Measure and mark the two points to drill for the T-nuts, don't make the holes too large for the T-nuts or they will fall out easily. I drilled 5/32" holes for the T-nuts 2-1/2" apart and about 1-1/4 from the one end. Measure and mark the 1" hole centered about 4-1/2" from the same end.

I drilled the 1" hole part way through the back then turned it over and drilled the rest of the way from the front to avoid splitting either side of the plywood.

When I was done I found that 4-1/2" seems a bit too close to the T-nuts you could move it a half to an inch further down. Also I found out that a 1" hole seems to make the higher notes sound louder, epically the B key. A smaller hole would tend to shift the emphasis to the lower notes. Using a 1/2" drill gauge held over the 1" hole seemed to bring out the F note.

Drill the 3 holes and tap the T-nuts into place with a hammer.

Step 4: Assemble the Box

Picture of Assemble the Box

Assemble the rest of the box (Careful not to knock the T-nuts loose!). Brads wouldn't look good on the top so just use glue and clamps. Be sure to use some sort of pad between the clamp and the box. They aren't shown in the picture because I forgot and ended up with some clamp marks to sand out.

- set it aside to dry

Step 5: Dowels and Rods

Picture of Dowels and Rods

Cut the aluminum rod to 4" and file the ends flat. I clamped it in the drill press and use the file to smooth and round the end off and used ultra fine sand paper to "clean" the aluminum. Carefully measure and mark the holes for the screws to attach the rod then drill the 2 holes at 1/8".

Cut the head and point off of the nail (3-1/4") and file the ends flat. Put it in the drill press to round the ends and clean as with the aluminum rod.Cut 2 lengths of the 1/4" dowel to 3-1/4". Flatten both dowels along the length just enough so they don't roll easily. Hollow out a channel on the side opposite the flat of one of the dowels to "cradle" the nail in place. I did this using a motor-tool while holding the dowel in a vice.

Set these parts aside for now.

Step 6: Sanding and Finishing

Picture of Sanding and Finishing

When the glue has dried, take the clamps off the box and start sanding. Sand the edges flat and sand off any imperfections or pencil marks from the front and back. I like to sand off all the hard edges and corners just enough so it feels good in my hands.
Dust it off carefully and put a coat of varnish on it. I put the bolts in the T-nuts so I could hang the box up to dry without it touching anything. When the varnish is completely dry rub it down with fine sand paper or steel wool to get a nice smooth finish. Put as many coats of varnish as you like.

Step 7: Final Assembly

Picture of Final Assembly

Assemble the whole thing as pictured. You don't need to glue the dowels or the nail in place, friction will hold it down when it's fully assembled. Be sure to place both dowels close to the aluminum rod (about 1/2" center to center) or the keys will bounce and buzz when you play it.

Insert one street sweeper bristle and tune it roughly to a C note. Mark it and "cut" it to length, actually I just put it in a vice and broke it. File and sand it carefully to round and smooth the ends, if you don't it will make a sound scraping across your finger prints or worse scraping off your finger prints! Re-insert it under the "clamp" and do the same for each of the notes you want, I added a total of 9. If you want more you'll have to either make the whole thing bigger or space the keys closer than I'm comfortable with. I put in keys for C through G then A through D in this pattern:


The pattern was suggested by a friend that had a bit more experience with musical instruments than I have, but other people have since made other suggestions so arrange them in any order you're comfortable with.

When they're all in, tune them carefully and tighten down the screws until you don't hear any buzzing when you play it.

Step 8: Finished

Picture of Finished

I added a sample sound file, it doesn't sound as good as the real thing. I recorded it with my cheap microphone on my computer.



b4k4hakujin (author)2007-03-31

Street sweeper bristles? I'm pretty sure we don't have street sweepers in downtownColumbia, SC. If we do I've never seen one. Is there anything else I could use? Rake teeth maybe? Even though rakes are kinda $$$ for ones with decent metal teeth.

BobsDogHouse (author)b4k4hakujin2007-04-01

Rake teeth sound fine, maybe a bit wide though. The sweeper bristles are only about 1/8" wide but there's lots room for wider bristles. What ever you use, as rashfreedom said it just needs to have some spring in it.

I hang around auto parts stores a lot. would the thin metal pieces inside a windshield wiper work?

I'm not sure, I don't have any old wiper blades to look at but it sounds like a possibility. Just make sure they're a fairly springy not "bendy". Also as I recall from changing my wiper blades, they're a bit sharp so you might want to blunt them a bit. Good luck and if you build one, post a picture!

SarahN95 (author)BobsDogHouse2017-09-21

I wonder about the metal from discarded hanging files.

I know this is a bit late, but yeah - i just made one out of them and it did work.

Pickles5000 (author)2011-10-24

Any ideas on what to use apart from street sweeper bristles?...
After a thorough search of my suburb i found one...

SarahN95 (author)Pickles50002017-09-21

You are looking for spring steel--old metal leaf rake tines, clock springs...I picked up a "cobra" toilet snake at the hardware store, the metal is a bit thick, but it works.

I have seen these made for kids with popsicle sticks instead of tines.

XxZombiexX (author)Pickles50002012-03-11

I used the steel from some old windshield wiper blades. Similar to the rake tongs (mentioned in other comments) just a little flimsier. I was pleased with how they sounded. Good luck!

mikas1428 (author)Pickles50002011-11-19

I think you could use chimney sweeper

Pickles5000 (author)mikas14282011-11-22


jgoodman13 made it! (author)2015-03-19

Thanks so much for the instructable! I went to the thrift store and found some wooden bowls then made the tops. They sound great! (author)2015-03-18

Really nice build and very clear instruction, thanks a lot I'm going to make one. I've ordered some electricians fish tape and downloaded a free smart phone tuning app from the Google store called Pano Tuner. Cheers and thanks - Jim

TinyBotics (author)2014-01-16

1) If I were to make an alto kalimba, do you know the relative sizes for the box and the tines?

2) Do you think it would be okay to use an old metal rake for the tines?

3) Do you think it can be tuned for the C3-C4 range?

jkbonesteel (author)TinyBotics2014-03-09

My kalimba is actually in that range, the dimensions are about 9'' by 12'' (keeping the 3/4'' height). The lowest key (C3) is about 2.5'' long, measuring from the aluminum rod. I tuned up from there. Hope that helps.

jkbonesteel (author)2014-03-09

When I made this, I found that very heavy-duty zip ties actually work pretty well. A problem that I found, though, was that the t-nuts would not stay put in the plywood, because of the pressure of the keys. I ended up just using a regular nut underneath the plywood with some washers. I found it to be much more secure.

msmith65 (author)2011-11-05

i couldn't find any street sweeper bristles so i used some metal fingers from an old rake

Timsan (author)2008-12-14
Having the aluminium rod means you can adjust the tuning if need be. You can even move the tines around to create your own custom tunings.

For example, if you use 15 tines (prongs), you can have a 2 octave major scale:
G E C A F# D B G A C E G B D F#

Or you can use an 11 tine setup to get a pentatonic scale:

The 8-note kalimba is an easy place to start. It's usually tuned to the major scale:
C A F D C E G B.

Have a dig through for more information on the types of kalimba, tunings and lessons on how to play it.

There's a stack of videos here:
I particularly like the one called "First Look Inside"

I'm amazed at what you can do with this little thing. I think I'll be making 3 or 4 of these little beauties!
BigBadgers2001 (author)Timsan2011-09-02

Truly, truly beautiful. I play Bass for blues, swing and rock, but that melody and the tone touched me so much. beautiful!

Timsan (author)Timsan2008-12-14

Just to clarify those tunings, the bold G in the middle is the longest tine. The tunings are in the key of G, but that's entirely arbitrary. You can tune it up in any key you want.

bigredlevy (author)2010-02-02

i made this one as a present for my brother. i used spring steel wire i bought from a hobby shop, and a nice piece of aluminium to mount the tines with screws for individual intonation.

ducktape.mac (author)bigredlevy2011-06-18

did you use the spring steel wire for the keys?

bigredlevy (author)ducktape.mac2011-06-20

Yeah. The wire was a bit thick, though. It wasn't very loud, but had quite a nice tone.
If you use smaller wire for the keys, the instrument will be louder, but the note will decay more quickly; this is due to more 'damping' with the air.

If you're keen on electric instruments, check this out

Yuri landman is my favorite instrument designer.

ducktape.mac (author)bigredlevy2011-06-20

thanks, i'm glad i found a substitute for street cleaner bristles.

theanzie (author)bigredlevy2011-02-03


CementTruck (author)bigredlevy2010-02-05


Just curious as to how this came out. Does it sound OK?

I have a buss bar from a house fuse box laying around somewhere and have been itching to do something with it. It looks a lot like the aluminum bar you have in your image.


bigredlevy (author)CementTruck2010-02-08

you mean one of these right? i think that would work fine. the advantage is that you can tune each note individually.
the problem i had with mine was the gauge of spring steel wire. i think mine was too thick, so the keys weren't as loud as i would have liked.

i tuned mine by ear using a piano. this would do

builderkidj (author)2011-06-18

Whats a thumb piano?

jakenzi357 (author)2010-12-13

awesome! Good job.

darkdragonv (author)2009-06-11

Have that same!

strato2598 (author)darkdragonv2010-09-20

hahahha lol SAME!!

amcasiano (author)2009-05-02

Thanks for giving me the idea to make my own kalimba. Keep it up!

BobsDogHouse (author)amcasiano2009-10-02

Very Cool! It looks great! Thanks for posting a picture.

TehLonelyOne (author)2009-09-28

This is great! definitely going to make one, is the steel you used for the keys 1/4 or 1/8 inch wide? It looks 1/8 but I can't decide which to use, since 1/4 seems to wide...

The steel I used was about 1/8 inch wide but the width doesn't really matter as long as it's wide enough to be "plucked" comfortably and narrow enough to fit and be tuned easily. I can imagine that tuning a very wide strip might be difficult but 1/4 would probably be OK.

CatMan (author)2007-03-31

Great Idea! my uncle brought one of those from Africa, when i was a kid i loved playing semi-african music on it. i've been collecting street-cleaner-bristles for other projects, but i'll defenetly use some of them for this project! i might use a premade box, being lazy, and I also like recycling stuff.

Oledoug (author)CatMan2009-10-02

We are way out in the country and have no street sweepers but one thing we have used is the small stainless steel about 1/8" wide piece of stainless steel that is in a automobile wiper blade. They are the dickens to cut but make a wonderful sound. Check with your local garage and have them save you some old wipers as they replace them for folks. Doug

CatMan (author)Oledoug2009-10-02

man, you read my mind, I discovered those a few months ago, and used them while building my anealling oven for glass-blowing. they are great because they are stainless. I didn't bother to cut them, just bent them and broke them. great stuff indeed, and for free !

yeah568 (author)2009-07-04

Heh, our local science center had like a workshop making these before. Basically, it was just a block of wood with two rubber bands holding the metal pieces in place. Wasn't as fancy as this, but it still works. Good instructable though.

ClemensY290 (author)2009-03-28

how do you tune this? do you just put a certain amount of the piece of metal on the side you play from the thing that holds them down?

MadBricoleur (author)ClemensY2902009-07-03

umm, okay. just look at it this way: the more the key (metal piece) is sticking out from where it touches the "nail support part", the lower the note, and vice versa. Just refer to an already tuned musical instrument to get the right pitch for tuning your thumb piano. hope that helped :D

Quinns (author)2007-03-31

Cool! I love making my own instruments and i'd love to do this one... but i live in australia and dont know what to use for the 'keys' any ideas?

fearme36 (author)Quinns2008-11-10

maybe you could cut up a pop can? idk but I'm gonna give it a shot. Ribs said Africans used flattened nails. if the pop can doesn't work i got some nails and a hammer =P (someone might end up dieing...)

MadBricoleur (author)fearme362009-06-28

nah... pop can metal would be really easily bendable and so it wouldn't be springy enough for keys. :( (author)Quinns2008-12-13

When I was in Zambia, many kalimba's made by hand used old stainless steel silverware handles. I bought two of them, one with part of a gourd mounted underneath instead of making a box. They both sound very different but neither of them was tuned. I think they are meant for display only. Having a tuned one would be cool.

rashfreedom (author)Quinns2007-03-31

I have used old metal rakes for the keys, it seems any steel that has more carbon than mild steel will work. Basically it needs to have some spring to it so when they are played the keys return to position. I have used Bobby Pins (hair pins) for small kalimbas (thumb piano).

spinach_dip (author)rashfreedom2007-04-04

Is the sound decent from the bobby pin ones? Of course it won't be as loud as the bigger ones, but is it audible, and does it stay in tune?

BobsDogHouse (author)spinach_dip2007-04-05

There's an audio link to a thumb piano that looks like it was built from something like an altoids tin and bobby pins, it sounds good. Start here:

MisterMissanthrope (author)2009-01-31

Still sounds good, and looks great, ive always wanted one of these, but im going to be working without saws soon, and might try making it from a box i find or tin something, nice ible.

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