Organ Backpack finished!

It has been a while since my last post because my phone, which was my only tool for documentation, was broken.

Basically where I left off was trying to figure out how to produce sound. There were a number of prototypes that I went through. Cardboard, paper, and finally PVC tubing. There are many examples of PVC music projects. Probably the most famous example is the blue man group’s use of PVC in their performances. PVC was the best option because it is relatively cheap (I got 10 feet for under 5 dollars from Home Depot!). PVC is strong, easily cuttable, and produces sound, all great characteristics for the project.

The length of the tube, I found out, is responsible for producing different tones. A longer pipe will produce a lower frequency vibrations which result in a lower tone and a shorter pipe will produce higher frequency vibrations which result in a higher tone. I cut three sections from my PVC pipe, each varying by about  6 inches.

After cutting the PVC pipes to size, I modified a 3D flue pipe from thingiverse user Japa: by sizing it to fit my 1 inch diameter PVC pipes. I also modified the mouth of the flue pipe to a diameter of 55mm to fit on the squirrel cage fan.

A squirrel cage purchased from sparkfun: and attached to two 9V batteries produced enough pressure to create sound from the flue.

After successfully producing sound, I designed and built and enclosure separated by three sections. Section 1 contains the fans, section 2 contains the Arduino, and section 3 contains the PVC pipe.


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