Arduino Dragon Wings
My daughter is REALLY into dragons, so this year we made her a set of articulating dragon wings that not only extend but flap and retract. She has three buttons to control it and can select from a variety of functions depending on the situation.
I made two YouTube videos on the project. The first one showcases the capabilities and teaches about what pneumatics can do when controlled by an arduino. The 2nd video goes into more depth about the types of cylinders and valves and what was required to make it work.
Design
At the beginning I wasn't even sure I could make a mechanism that would do what I wanted. But that's where CAD (Computer Aided Design) can help you flush out your ideas before you even pick up your first piece of material. Once I got it moving in a virtual world like I wanted I was able to take measurements and create the mechanism. Whatever project you're doing, CAD is a big help refining it and getting it closer to something that could actually be built.
Construction
I could have made this project out of a variety of materials, but I needed something strong AND lightweight. Aircraft grade aluminum (6061) seemed like the perfect material and fortunately I'd recently invested in a TIG (Tungsten Inert Gas) welder which made it much quicker without the need for special fasteners at each connection point.
For the parts that didn't require the strength of aluminum, a 3D printer made even lighter parts that I didn't have to spend time fabricating.
Components
Rather than mess with servos or stepper motors I decided to use pneumatics. I've long wanted to show people how a microcontroller can make stuff move in a cool and simple way and this seemed like the perfect opportunity to do that. The main power source is a CO2 tank like the kind used in paintball. The valves were simple solenoid valves and the air cylinders were whatever I could find off Ebay.
Unfortunately the valves were 24 volt and I wasn't about to strap 16 batteries to the back of this thing. Instead I used a boost converter. Not super efficient but it did a great job stepping the 12v battery pack up to the 24v the solenoids needed to run.
Putting It All Together
This thing looks like something that wants to destroy itself. And it actually did more than once! But in the end I was able to route all the wires and tubing in places that weren't going to get cut or smashed through normal operation. I tucked the inputs for the arduino inside a 3D printed case which so far has worked great!
Programming
A programmer I am not, but fortunately my son is quickly becoming one! Once he got the bulk of the program setup how I wanted it I was able to change the timing of the wings to my heart's content until it performed how I wanted.
Smoke Machine!
I do enough work with kids and science fairs that I have my own smoke machine on hand for situations like this. I had no idea how good it would look with the wings flapping and swirling the smoke around. I got the whole family involved for the ending to the video and can't wait for Halloween in just a couple days!!!