Development of a wind driven soap bubble machine for my bicycle

So now I finally have a 3D printer, what do I do with it? Printing out downloaded vases, gifts for children is one thing. Wanting to create my own 3D models I quickly came to the vast field of replacement parts for all the things that can break in a household — cool, yes, but this thing is supposed to stimulate my creativity, not just please my wife.

Volunteering at our local kindergarten’s summer party I spent 2 hours animating kids and playing with soap bubbles, small and giant. A lot of time to get you thinking. Of course there are a lot of soap bubble machines out there, but mostly they are supposed to be driven by electric motors. I imagined a large wind wheel, aligning itself with the wind, but our garden, as well as the kindergarten, are pretty much protected by any wind. It was then when I had the idea of a soap bubble machine mounted to the side of my bicycle’s back part: when cycling, a wind wheel would make a ring of bubble wands rotate, picking up bubble liquid; instead of an electric fan, the relative wind while cycling would blow the bubbles.

Of course, there are some unknowns in this:

  • how much wind do I need to create bubbles? Relative wind on a bicycle also isn’t as “focused” as the air stream created by someone blowing on a bubble wand. And: will too much wind have a negative impact?
  • will the torque of the wind wheel be enough to overcome the resistance of the bubble wands passing the bubble liquid?
  • what’s the right position for this to mount? Obviously not the handlebar as I don’t want to have all the bubbles in my face — but if I mount it somewhere behind me on the side, will there be enough wind or too many turbulences?
  • how can I keep the bubble liquid from spilling on a rough ride?

A 3D printer is perfect for this kind of fun project for several reasons: of course, creating a custom bubble wand wheel would be much more difficult without it. But there’s another reason: with a 3D printer it’s much easier to just take a plunge into this problem, just trying out things instead of spending days and weeks on meticulous calculations of air flow, friction etc. You just design something, print it out and see if it works. Then you try again, and again, and again.

My first try was promising enough so I decided to continue:

1. First Steps: The Too Simple Solution

2. Separating Wind and Bubble Wheel