If you are like me and every time you crack open a coconut you find the shells just too cool to throw out then this instructable is for you. The idea of making a coconut shell thumb piano came to me one afternoon while I was trying to come up with some way to entertain my 3 and 5 year old girls. Of course after making them each one I needed to see if I could amp one up for myself. This was way too cool of a project not to try. As usual with all my instructables look to the image notes for the details.
Step 1: Lets Get Wired
In this step you will have on hand half of a coconut shell that you have already sanded flat across the opening and sanded off all the stringy bits on the outside. You will also have harvested a piezo element from a Dollar Store window alarm as well as a 1/4 inch stereo or mono jack. You will also need about 6 or 8 inches of speaker wire (or the power cable off an old AC adapter). Some wood for the top and some hot melt glue.
Step 2: Sound Board Meets Body.
Here you will glue the sound board to the coconut shell. I should mention that I am using a very high quality industrial hot glue for this project. Also pick a spot on the sound board to drill about a one inch hole that will be your sound hole. Just look at the pictures to get an idea of where it should be.
Step 3: Building the Bridge
Start with a couple of dowels cut to fit your sound board , you'll have to figure out how long they need to be based on the size of your coconut shell. You will also need a piece of 1/8 inch by 3/4 inch steel bar stock. with a couple of holes drilled in the ends that will allow a screw to slide through. And of course you'll need some hot glue.
Step 4: Making the Keys and Setting Them in Place.
Now it is time to make the keys for your piano. I chose a 3/8 inch band saw blade that I cut into 5 pieces each about 3 inches long.