Adding Movement

A project log for Nova - A Companion Bot

Building a sweet little shoulder dragon to accompany my Color Stealing Fairy project.

Angela SheehanAngela Sheehan 05/10/2020 at 21:170 Comments

The most important part of this project, and new skill for me, was creating natural and whimsical movements. One of the most compelling things about the companion bots I have interacted with is their randomized movements that begin to feel like responses to their environment. 

My first challenge was how to create flapping wings with the least amount of parts. After a lot of research and thought, I came across a gripper attachment for a servo that looked like it might be adaptable for a coordinated wing flap - eliminating the need for two servos to drive her wings.

This worked far better than I expected! I adjusted the 3D printed wing enclosures to include a notch that matched the profile of the gripper arms. To install them, they are press fit on the arms and stay relatively secure. Over time, the print has been wearing down where they attach, so I am going to upgrade with a bolt or other fixture point for long term stability.

I programmed the movement of the wings to have a 'resting' pattern of occasional flaps, with a more excitable flapping when she is activated by a touch sensor on her face. Below is a video from early prototyping of adding the touch sensing to trigger color changes in her wings.

The next step was to add some movement in the face. Since I designed Nova's head as a single sculpted piece, I decided on a bird-like head tilt with a second servo to add the effect of a curious creature surveying her surroundings. After some testing with code to create a natural range of movement, I mounted the servos in a 3D printed body base.