The Kawika Hula Girl Shaker Break-In Tool for Ukulele and Guitar

While I'm waiting for my shipment of bridge blanks to arrive, I need to find some other trouble to get into.  I had been reading David Hurd's ukulele pages and was intrigued by the "Hula Girl" shaker.  I decided to make one, since I happen to have a new ukulele that could use some break-in.

There has been a lot of experimentation into and discussion of "breaking in," or "dedamping" acoustic instruments.  The first time I became aware of it was in Tom Wheeler's "The Guitar Book," where he briefly mentions it, and says that "violins kept in museums must be periodically played to keep up their tone."  Roger Siminoff, well-known author and luthier, even offers a dedamping service.

Making the Kawika Hula Girl Shaker is pretty straightforward.  You need one garden-variety small speaker. 

I have three 4 inch speakers on hand.  I need one for my GE radio restoration, but I can sacrifice one for this project.

Cut out the speaker cone, except the part where the coil wires are glued on.  It felt very strange doing this!

Then cut the speaker frame off, except the arms where the terminals are mounted.

Drill a groove and a hole in a closepin (see the Kawika page for more detail), and glue a dowel to the speaker and to the clothes pin.

Wire up the speaker to a headphone connector (I used a 1/8 inch connector) and to the speaker terminals.

Put the groove over your strings, and use the pin (I cut a brad) through the hole in the clothespin.

Here's my Hula shaker on my new Lanikai O-8 uku being driven by one of my Hacker radios.  I tuned it to a local classical station - I thought the wide frequency range of classical music would be a good thing. 

The ukulele actually becomes a speaker!  The vibrations from the speaker coil are transmitted to the clothespin and then the ukulele body.  You can hear the radio via the uku.  And you can feel the vibrations.

I'll leave it on for about a week and see what tonal changes there are.