Instant Thumb Piano: How to Make a Set Screw Lamellaphone

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

About: RP Collier - artist, musician, writer http://cdbaby.com/cd/rpcollier/ http://rpcollier.bandcamp.com/ https://soundcloud.com/rpcollier

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

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

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

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

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

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

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
hairpin
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

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

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

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.

Step 10: 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
http://soundcloud.com/rpcollier

New 2008 all thumb piano audio album:
Lamellaphone - http://cdbaby.com/cd/rpcollier4
http://www.doncampau.com/lw2007.htm

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 Suddensound.com also provides a great example of using mallets or drumsticks to tap long tines in the grounding bar which results in good bass tones:
http://www.suddensound.com/workshop/hammeredkalimba.html
Check out the sound sample:
http://www.suddensound.com/workshop/samples/hammeredkalimba.mp3



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57 Comments

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.

montecristo kalimba finished.jpgKalimba Oliva.jpgBobby Kalimba (1).jpg
1 reply

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

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.

http://makezine.com/projects/thumb-piano/. You even used the same words, or did they copy you?

3 replies

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

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

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.

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?!

3 replies

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.

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?

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.

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.....

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.

IMG_2738.jpg
2 replies

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.

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.

IMG_2736.jpgIMG_2739.jpg

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

3 replies

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 . :)

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

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

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