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.

Step 1: Step 1 - Materials and Tools

The Slap-O-Fone will work by slapping the end of a tube to create a sound.  As you change the length of the tubes, the pitch changes (longer tube = lower pitch, shorter tube = higher pitch).  Any tubes will work for your Slap-O-Fone.  I have read comments where people suggest 75mm diameter (3"), 12mm (1/2"), and everything in between.  I suggest using whatever you can find plenty of for cheap.

Materials I used because they were on-hand and free:
- 75mm diameter cardboard tubes (the kind that large rolls of paper are spooled onto for plotter printers) that are 92.1 cm long
- cardboard boxes (these were the boxes that held the paper before the rolls were emptied)
- pencils
- drink coasters  (cheap cardboard ones)

Tools I used
- cutting tool (i used a knife but a saw could work depending on your tube material)
- tape measure
- writing utensil
- elastic band
- hot glue
- duct tape
- Microsoft Excel (you could use a calculator, pencil, and paper instead)
How do you know what length of tube makes what note?
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.
people have made them out of pvc pipe too
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 &quot;The Musical Organon&quot; which uses similar cardboard tubes: <a href="http://www.instructables.com/id/The-Musical-Organon/" rel="nofollow">http://www.instructables.com/id/The-Musical-Organon/</a>
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.
I loooove that name! How cool is it to say: &quot;ya, I play lead slap-o-fone.&quot;
Great project for kids. I've also heard it referred to as a tubola; see <a href="http://www.pas.org/experience/onlinecollection/tubaphones.aspx">http://www.pas.org/experience/onlinecollection/tubaphones.aspx</a> (scroll to bottom). The Disney folks used flipflops for mallets for that classic cartoon sound.<br>

About This Instructable


61 favorites


Bio: I am an educator, technologist, maker, facilitator, scientist, and artist. I have a small streak of creativity for producing new things, but I think I ... More »
More by veebz: Slap-O-Fone
Add instructable to: