Today, robotics are usually based on servos, steppers, and other electrical gadgets, but before people had access to this type of technology, simple “robots” could be made by translating movement from a rotating shaft into other motions. Linkages and cams used in industrial automation are a simple example of this, but they can also be made to look like a human or animal, like those you might see at a theme park. With quite a bit of work, you can even make your own!
Concordia University Mechanical Engineering student Ryan Bondyra decided to make his own piece of automation as as a present for his long distance girlfriend, Elisabeth. His automaton takes the form of an outdoor scene where a male and female character look at each other while the sun and moon rise, and animals interact in the background.
The project began with Bondyra braistorming and sketching everthing up on paper. He considered this a fun challenge, and also the most important part of the project. Ideas for how it worked came from different YouTube videos of similar automata, and from websites like 507 movements, which illustrate different mechanisms.
Once he was sufficiently inspired, the project was modeled in SolidWorks, then he had a local shop print the items he needed. When they arrived, the quality was better than expected, and after assembly everything ran smoothly. Once he painted the model, there were a few issues with it interfering with the movement, but after some adjustment he got nearly everything* to work as planned.
Besides being a great project in its own right, what perhaps sets this project apart is that it is excellently illustrated in several animations seen on the project’s imgur set. Since Bondyra modeled the structure in SolidWorks (he has access through his school) before building it, creating these animations wasn’t too difficult, and really illustrate nicely how everything works in this type of device.
The build only cost Bondyra $80 in materials, including some cheap paint and brushes as well as printing via William’s Hub, a local 3D printing service. Though this seems extremely reasonable for a custom piece of mechanical automation, you might consider that it also took him a long time to make. According to him:
The total time for the project was about 100 hours however 90% of the time was spent learning. This included 10 hours of researching previous projects and getting ideas, 30 hours of design, 30 hours simulating & modifying the design, 20 hours of painting & prepping parts, and 10 hours of assembly. If I were to do a similar project again, it would probably only take 20 hours from start to finish.
The build looks great to a casual observer, but with any project it seems that the creator always has a few things that he or she could improve next time. Bondyra says that:
I’m very happy with how everything turned out except for the paint. It was my first time painting anything other than walls and I was rushing to finish as my girlfriend’s birthday was fast approaching. If I had more time, I would have repainted everything. If I were to do this again, I would learn to use a different software, such as Blender, to design the characters, and then import them directly into Solidworks. I also would have made the entire thing slightly bigger. Printing the parts in the same colour plastic as their final colour would also have been a good idea.
What he thought about his creation is interesting, but what about Elisabeth? According to him:
She absolutely loved it! She said it was the best and most thoughtful gift she ever received. At first she didn’t know what it was exactly, but when I showed her how it worked and she saw everything moving, she cried and couldn’t stop playing with it. She especially loved the little details like the colours of the clothing as her jacket in real life is lime green and mine is dark grey.
It’s a really neat piece, and a great reminder that, although servos, steppers, and microcontrollers are great for maker projects, there is more than one way to create custom movements. Though certainly not easy, something like this seems like a very satisfying project if you’re willing to put in the time!
*The boy’s arm doesn’t move as in the simulation, as the painted arm sticks to the shoulder hinge.