One of the projects for Design Nature, the freshman introductory design course, is to work with a team to build a toy for 4th graders that can climb up a vertical glass surface. As with the hopper project, the majority of the device had to be build out of laser cut plastic.
This time, however, we were given a commercial product that already successfully walked up glass. We dissected them to figure out how they work, and took suction cups and bellows from them for use in our own walkers. The walker had to be bio-inspired, so for my group’s walker, we chose to mimic the motion of a snail. Since forth graders were our target audience, we decided that having our "snail" leave a slime trail behind itself would be a big hit.
After a few prototypes, we constructed what might be the simplest walking mechanism of all the walkers. It relied on two independently cammed gears: one for the walking motion, and another to control the suction cups 90 degrees out of phase with the walking motion. One of the hardest parts of the project was getting our ideas into workable concepts, then CADing them into parts, then assembling those parts in real life. A few times, we wound up designing impossible mechanisms and had to go back to fix them.
Our final walker was able to walk up a 42 degree incline, which was fairly good. No one was successfully able to climb a completely vertical surface.
Below is video of us testing out of final walker, the Fire Snail.
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