1. + 3D Printing By Yolanda Colon

2. + Building Bridges Original work by Yolanda Colon

3. + Learning Objective Grade Level: 4 th grade Objective for student: To understand what a truss bridge is and learn how the structure is built. Be able to conduct an experiment in groups and build their own model of a truss bridge out of the materials given to them.

4. + Description of the Lesson Students will look at the 3D model of a truss bridge I will have on display. They will look at the shape of the bridge, structure, beams, and support system in place. Students will need to be able to touch the 3D bridge to see how they should build their own bridge. Students will have prior knowledge on 3D printing from watching a video on 3D printing before this lesson. Students will work in groups on building their own model of a truss bridge out of the materials I have provided: popsicle sticks, cable ties, markers, and glue gun. There will also be older students or volunteers available to assist the students.

5. + Procedure Using the popsicle sticks, link them together by using small dabs of hot glue form the glue gun in triangular shapes. Continue step one until you have 7 triangles linked together. If there is time, students can strengthen their bridge by adding more popsicle sticks to the middle of the triangular shapes. Repeat Steps 1-3. These two parts will be the sides of your bridge. To create the bottom of the bridge, you need to use the popsicle sticks (4) to create a rectangular frame. Create for linking rectangular. If there is time, reinforce it with the “trusses” in the middle (x shaped popsicle sticks). Bring the two sides of the bridge together on top of the bottom piece and tie together with cable ties.

6. + 3D Printing Learning Activity Students will learn to understand how each part of a truss bridge is important to the structure as a whole by observing the 3D printed truss bridge model.

7. + Purpose of the 3D Printer Without the 3D printed model of a truss bridge, students will not be able to see each part of a truss bridge up close. They also will not learn the valuable information without this model needed to do the experiment.

8. + Assessment Plan I will assets students by checking for understanding on the different parts of a truss bridge. Also ask students questions on how the 3D printer printed out the truss bridge. Ask students questions on what they are doing when they are conducting their experiments and what materials they are using and why. If students are answering these questions correct then I will know the objective has been met.