Picture of Slap-O-Fone
After seeing this video on MAKEzine I decided that I was going to start collecting parts to build my own "Slap Tubes."  I did some research and discovered that the physics involved is fairly straightforward.  Most of my research came from this handy guide to building your own ESPAS (End Struck Plosive Aerophones - the technical name for this type of instrument.).

These instruments are extremely simple to design, build, and play.  They can also be made to be extremely cheap (free in my case) or very expensive (if you use PVC and make a huge set with many octaves.)  As an educator, I think these instruments could make for a great cross-curricular lesson involving music, physics, art, and just plain ol' fun because they are pretty simple, and have the potential to be very very cheap.

I will try to show/explain my steps in a couple different ways to accommodate for the various learning styles in the audience.  If you would like to know more about the theory behind my design please check out the guide linked above.

While I will try to be as clear as possible, bear in mind that while my steps are specific to my materials, the general process will be the same regardless of what you build your instrument out of.
tmcfarlane12 years ago
How do you know what length of tube makes what note?
veebz (author)  tmcfarlane12 years ago
Step 2 explains this. There is a spreadsheet that can do the calculations for you and 2 links to websites with additional information and tools.
ace14234 years ago
people have made them out of pvc pipe too
veebz (author)  ace14233 years ago
I have seen them made with pvc and I plan to experiment with a few pvc options. I would like to make a small scale portable one and a large scale stationary one.
Think you might like our project "The Musical Organon" which uses similar cardboard tubes: http://www.instructables.com/id/The-Musical-Organon/
veebz (author)  fish.fingercorp3 years ago
You are correct, I do like you're project. That's a pretty nifty machine. I always like finding interesting ways to blend art and technology/science. Thanks for the suggestion.
bgepp13 years ago
I loooove that name! How cool is it to say: "ya, I play lead slap-o-fone."
ToniRose4 years ago
Great project for kids. I've also heard it referred to as a tubola; see http://www.pas.org/experience/onlinecollection/tubaphones.aspx (scroll to bottom). The Disney folks used flipflops for mallets for that classic cartoon sound.