In fall of 2016, we embarked on one of our more ambitious projects – converting a broken down wheelchair into a fire-breathing, animatronic dodo bird. This page was set up to catalog our build.
Concept Sketches
We set started this project by rebuilding an old electric wheelchair we picked up on craigslist for $100. The batteries and control electronics were shot, and a few pieces were missing.
We started by stripping off the chair with its associated actuators and controllers.
The wheelchair controller was dead so we needed to figure out how to wire in our own. The photo below shows the c300 wheelchair motor controller wired into an Arduino for initial testing.
Once it looked like it was working on the bench we wired it onto the wheelchair.
Motor tests with the Arduino left something to be desired, the PWM frequency out of the little guy was just not enough to drive the motor controller.
We replaced the Arduino with a more powerful microcontroller, and ARM32F0 which then allowed for smooth motion
Once we had the wheelchair platform responding to our commands we decided to try riding it around a bit!
Now that we were sure the wheelchair was working, it was time to break it down and build a model of it.
We completely disassembled the base, carefully measured each component to build a 3d model. This allows us to design large portions of the Dodo before we are at the shop throwing sparks.
The CAD model took us nearly a month of difficult work to complete. The benefit of creating this model is we can bring a complete set of spare parts in the event something breaks. We know every washer, every bolt, every spring, and every bearing on our little bird.
Since the wheelchair was now in pieces we gave it a good cleaning and got it a new set of tires.