The Miami-Dade Public Library hosted a series of innovative, technology-based programs for center city youth that focus on Science, Technology, Engineering, Art, and Mathematics (a/k/a STEAM).
A Mechanical Engineering class at the North Central Branch was attended by over twenty students. The class is the brainchild of Carol and Brianna Frachtman and is one of many offered by their school Engineering For Kids Broward. It focused on the creation of two hands-on projects that introduced a variety of engineering concepts and skill sets to a highly enthusiastic group of youth.
“We like to build on children’s natural curiosities and unlimited imaginations by offering inquiry-based, collaborative lessons that spark enthusiasm. It’s about discovery and play and having fun while learning,” said Carol.
The first lesson centered on the creation of a Candy Catapult. Carol explained how these simple machines were used to hoist weapons above the high ramparts of medieval villages. The youth were given all the supplies needed to create their own catapult, the foundation of which is a box of DOTS gumdrops. When several students asked if they might consume some candy, Carol quickly explained how that would compromise the volume and weight of their catapult’s foundation—the box of candy—and they might not be able to get enough tension to hurl their projectiles where they wanted.
To foster team building, the students broke into small groups and assembled their catapults. Once the catapults were completed, the concepts of accuracy and precision were discussed.
Accuracy measures how close you get your projectile to the desired target, while precision introduces the concept of aim. Aim in turn requires the youth to factor in things like the volume/weight of their projectiles (marshmallows were used) and how much tension they need to apply to get the projectile to travel all the way to their desired target as accurately as possible.

Students take aim in a Mechanical Engineering class
After testing her aim through trial and error, student Lisa was able to knock down five Styrofoam coffee cups in a row with her projectile; she was very excited about this accomplishment. Another student, Yorel, was aiming at a conventional plastic target and was quick to exclaim “I got a bullseye!”
Building self-satisfaction and esteem are clear byproducts of this pedagogical approach.
The second lesson of the four-hour program, Coasters 101, addressed gravity, inertia, momentum, and acceleration as students assembled miniature plastic roller coasters. The youth again broke into small groups to work as teams. The only requirement was that each coaster have one hill and one loop-the-loop. The hill and loop-the-loop could be anywhere, but a marble needed to be able to travel down the plastic tracks from the top of the coaster to the finish line.
Planning, designing, creating, and testing were displayed throughout both lessons. During the testing phase of the coasters, one of the teams realized that their hill wasn’t steep enough to give their marble the momentum to get from the top of the coaster through two loop-the-loops and over a hill to the finish line. Testing is an important facet of the lesson, so the group adjusted one of the loop-the-loops and also raised the hill. The result was the marble racing through the coaster to the finish line with speed to spare, much to the satisfaction of the group who cheered their accomplishment.
A Children’s staff member, observing the youth’s enthusiasm, commented “how rare it is to see [youth] this enthused about a program three hours into it, let alone a four-hour program on mechanical engineering.”
Funding for this series of programs comes through the generosity of the Knight Foundation and the Friends of the Miami-Dade Public Library.
Brian Colleary is a Branch Manager for the Miami-Dade Public Library System.
We have done a STEM program with catapults before at my branch too, and they are a big success! I love the idea of using a target too.