As a final project for my Introduction to Engineering class for my high school freshman year, our class had to create a cam toy. This type of toy displays a repeating, moving pattern of objects through twisting an axle, that goes through an open box, which has “wheels” with various shapes. These “wheels” allow the same number of sticks, which go through the top of the box, to be risen and dropped at different times and at different speeds.
For our project, we could create any type of design that we wanted as long as it fit the criteria of how the motion had to be consistent and repetitive as well as other minor details. Through this, and with Avengers: Endgame coming out last month, I decided to create something based on Thor’s new weapon, Stormbreaker, and Captain America’s shield. At first, I started with this sketch of the idea:
After getting the general idea on what my creation would be, I began to work on the 3D models of the project on Autodesk Inventor. These were the final designs of Stormbreaker and Captain America’s shield along with the cams (the “wheels”):
In the design, I created a small hole in the axe on the end of the handle in order to act as a slot for the axle. Additionally, the shield had a square indent on the bottom of it so that it could fit onto the stick that would be moving up and down. Then, I tried to paint the shield with “okay” results because I didn’t sand it or use primer beforehand.
Finally, with the design of the whole toy on Autodesk Inventor finished, I began building the physical model. However, I had to make some changes throughout the course of the project that deviated from the original concept sketch. I was going to use to “snail” cams (the black one in the picture previously) but found that the timing between the axe hitting the shield and the shield dropping to be difficult to achieve because they would almost simultaneously occur in a split second. So, I changed the snail cam on the shield to be a hexagonal one. These mimicked different movements; the snail cam represented a gradual rise and a sudden drop whereas the hexagon represented a quick rattling/quivering of the object.
Also, I changed the axle to be placed higher because I wanted to take attention away from the box to the actual movement occurring and give a feeling of “openness.” There had to be borders added to the stick that was moving the axe up and down because the axe sometimes slid off the stick. Also, the stick’s end had to be rounded so that the axe would move without any interference. The axle was improvised with a bulliten board pin and a wooden dowel. The pin fit perfectly in to the Stormbreaker‘s as an axle, and the pointed end was bent and covered with hot glue in order to make it safe.
This was the final design:
Update; Here’s the video of the toy:
All in all, the experience of designing my own product taught me that function comes before visual appeal. The visuals will form after you find out who you are designing something for and why you’re designing it. It was an interesting project and at first, I wasn’t very confident in my ability to make this toy. But, I decided to try it out and that the worst thing that could happen was I would have to make something else. There were flaws, no doubt, but the major ones were overcome by looking at the simplest solutions to them. Through this course of Intro to Engineering, I learned that designing is about the function of the product and the use of the product you are providing.