They can identify cause and effect relationships between these elements and the robot's movement. There are many other design factors your students will have to consider when building their robots. Slanted legs can be used to give a robot directional friction so it moves forward. However, robots with legs that are angled to the ground will experience lower friction in the direction the legs are angled and cause the robot to move in that direction.įigure 2. When vibration based robots have legs that are perpendicular to the ground the motion of the robots will be random as horizontal friction forces are equal. Robots with slanted legs will tend to move more consistently in the direction with less friction. The same concept can be applied to junkbots by giving them slanted legs (Figure 2). Now think about petting a dog or rubbing your finger along a toothbrush with slanted bristles-it will feel smooth in one direction but rough in the other direction. Think about rubbing your finger along sandpaper-it will be rough in any direction. The key to making them move in a (relatively) straight line is directional friction, or making sure the parts of the robot that contact the ground have more friction in one direction than the other. However, without some careful design choices, junkbots will tend to move randomly or spin in circles. This is the same concept used to make cell phones and video game controllers vibrate-they have tiny motors with off-center weights inside. This makes the motor vibrate, causing the robot's entire body to wobble. Your students will attach an off-center weight (a cork) to the motor's spinning shaft. If the positive and negative leads between a battery and motor are crossed then a short circuit occurs and the motor receives no power (motor does not spin).įigure 1. In a closed circuit, the positive and negative leads are connected and the motor receives power (motor spins). In an open circuit, there is no connection between the wires of a battery and motor so the motor receives no power (motor does not spin). Open floor space on a smooth surface (not carpet)Ī battery must be correctly connected to a motor for both to function properly.Optional: hobby knives (adult supervision recommended for young students).Optional: hot glue guns (adult supervision recommended for young students).Assorted craft materials (pipe cleaners, googly eyes, etcetera).Assorted recycled materials (cardboard, clean plastic bottles, etcetera).Other household items include a cardboard box, glue, rolls of tape, scissors, plastic cup, plastic bottle, cork, popsicle sticks, paper clips, plastic straws, metal cans, and a cardboard tube.įor each student or small group of students building a robot, you will need these items in theīristlebot Robotics Kit from our partner Home Science ToolsĮnough parts for two Junkbots, as well as parts for two To build a junkbot you will need a motor, a battery pack, and two double A batteries. Structures can be designed to serve particular functions by taking into account properties of different materials, and how materials can be shaped and used. Cause and effect relationships may be used to predict phenomena in natural or designed systems. A solution needs to be tested, and then modified on the basis of the test results, in order to improve it.Ĭause and Effect. Evaluate competing design solutions based on jointly developed and agreed-upon design criteria.ĮTS1.B: Developing Possible Solutions. This lesson focuses on these aspects of NGSS Three Dimensional Learning: Science & Engineering PracticesĮngaging in Argument from Evidence. Develop a model to generate data for iterative testing and modification of a proposed object, tool, or process such that an optimal design can be achieved. This lesson helps students prepare for these Next Generation Science Standards Performance Expectations: Apply the engineering design process to iteratively test and improve a robot.Understand the difference between open, closed, and short circuits.No previous robotics experience is required! In this lesson, your students will learn about engineering design as they compete to build the fastest robot. Junkbots are easy-to-build robots that you can make using a simple circuit and some recyclable materials. Create Assignment Create Announcement Overview