It is only our third week in Turlock; but, I already have repeat students, which compelled me to come up with new STEM (Science, Technology, Engineering, Mathematics) projects during our break-out sessions. This wasn’t very hard given the scope of STEM-related fields.
However, this also meant that new students missed some of the previous experiences, which include dancing ballerina (a homopolar motor), kinetic gearbox, balancing levers, self-propelling rubber band car, straw tower, wall rebounding car, hashing and sorting algorithms, and more…
At the risk of repeating an activity and a discussion, I shared previous ideas, which served as a review to repeating students. Some of these ideas are shown in above image and I will go over them in them in this blog.
The top right corner of the image is an H-Bridge model, which is used to change the direction of a DC; thereby, controlling the rotational direction of a DC motor. After playing with the model, the students got an opportunity to take a closer look at L298N Integrated Circuit, which is used in small robotics as H-Bridge to control the direction of the robot motion.
The robotic arm to the right of the image is a six Degrees Of Freedom (DOF) robotic arm, which presented numerous discussion points. We compared the robotic arm to human arm (7 DOF), talked about the gripper gear that uses only one motor, how rotational movement translates to linear motion, and how we would need to calculate the location of the end-effector.
Next, we discussed the mechanics of gears and demonstrated them with a lego technic set (bottom right of the image). Students were able to see and feel how gear ratio affects torque output. We discussed engineering trade-off and rationale for choosing higher torque for power (truck or jeep) as opposed to a race car. We also got an opportunity to review the benefit of the worm gear and how it can be used to hold a robotic arm in place.
During one of our breaks, students built a scissor gripper, which is essentially half of the “scissor lift” (in the middle of the image). Again, students had an opportunity to build and play with a lever system that is used in numerous applications.
We also took a closer look at a rover robot (left-middle of the picture), which was another important point of discussion because every student has been programming a character (monkey, zombie, bee, etc) to advance and move in multiple directions. Their coding knowledge of conditions, loops, and modules is directly applicable to programming the robot and it was important to highlight their new found skill, which is controlling robots and the physical world.
The last item in the picture (top left) is a DIY model of a simple robotic arm. I shared with my students that we can build a simple robotic arm for about $5-$10 (as opposed to $150 arm to the right of the image). Coming up with a cost-effective model to test/play with has been the theme of STEM Learning Education; so, it was important to me to showcase how kids can be resourceful and build useful and tangible elements.
Lastly, we closed out the day with a fun activity of building and firing rings of smokes through a vortex cannon.