Creative Cantilever Challenge
Hosted by: UT Austin Architectural Engineering Institute
Visit our Booth: Saturday, February 27, 2021, 12 p.m. - 4 p.m.
Build your own cantilever, a balanced bar that is supported by a wall or the ground, like a pool diving board.
Recommended Grades: 6th, 7th, 8th
The Challenge: Create your own cantilever that reaches a maximum distance beyond the edge of a tabletop without going below the top of the table. How far can your cantilever go?
A cantilever is a balanced bar that is supported by a wall or the ground, like a pool diving board. Cantilevers can be built with any materials you have at home. See below for recommended materials and more information about the challenge. Check out the "Steps" tab for the process one of our own engineers took to create a cantilever.
- Straws, sticks, popsicle sticks, or toilet paper rolls
Additional Instructions and Tips:
Share your design on Flipgrid.
What did you learn?
A cantilever's length depends on the size and shape of the bar. In some cases, short cantilevers are needed like the ones you made. Other times, cantilevers are used in buildings. These cantilevers have to be made carefully so they always remain in balance and not fall. Which shapes and sizes did you notice were best when you built your cantilever?
How did a UT Austin Architectural Engineering Student Approach This Challenge?
First, I tried making a cantilever from a deck of cards.
I placed the cards on top of the deck, each one a little bit more outside than the previous. I was able to place 14!
Then, I tried making a cantilever with a chopstick.
When I placed the chopstick in the middle of the deck of cards, it was balanced! But, I could make the cantilever longer by pushing the smaller end of the chopstick out until the point before where it is not balanced. I also tried pushing the bigger side of the chopstick outward, but it lost balance faster than my previous attempt.
Lastly, I experimented with a toilet paper core, the cardboard part. First, I placed the cylinder in the middle of the deck and pushed it out until it was about to fall. The cantilever was not long, so I tried changing the shape of the core.
I folded the toilet paper cardboard into a triangle, like a triangular prism, and moved the cantilever in the same way as the previous step. It seemed like the length of this cantilever is the same as the one before.
I changed the cardboard core again into a square shape, like a rectangular prism. And I moved it, as usual, but it provided the same length result.
Finally, I folded the core into an "I" shape, like the beams that are used in building construction. After placing the cantilever, I noticed there was a tiny improvement to the length of the cantilever.