8 Tooth Gear

thingiverse

Students work with diverse toothed gears and design different scenarios where gears can be set up for either torque or speed. This engaging hands-on activity allows students to grasp gear ratios. How I Designed This We previously explored Autodesk 123D Design for Education in class, and the images represent the creation of different gears with various numbers of teeth created by students. The images below outline the steps to create their gears. Standards NGSS Overview and Background Students create and build a range of different-sized gears and assemble them into simple gear trains. Students receive a brief overview of how to create gears in 3D modeling software and convert files for print. Students then use their mechanism to demonstrate the differences between building a mechanism for torque and building a mechanism for speed. Students count the number of teeth on the input gear and count the number of teeth on the output gear, dividing the counts by each other to determine the gear ratio. Once different simple gear train mechanisms are created and gear ratios calculated, students set up their designs and quiz their fellow classmates. Lesson Plan and Activity This is a 4-day lesson with variable duration for each step based on classroom setup and materials. Background and Preparation: Students have already demonstrated mastery in designing with 3D modeling software. Students have received background information on different mechanisms that create torque and speed. ~Makerbot 3D Printers and filament ~Computers with modeling software ~Paper, pencils, other note-taking materials for students Day 1 (55 minutes) - Attendance, students prepare personal notes for the lesson (5 minutes) - Review previous lessons on mechanisms and simple gear trains; students take notes where needed (15 minutes) - Review 3D Modeling software and how to design; students take notes where needed (25 minutes) - Teacher checks understanding and addresses student questions, cleanup (10 minutes) Day 2 (55 minutes) - Attendance, review of expectations for today's lesson (5 minutes) - Students begin designing gears on computers. Higher-level students start printing and assist others while waiting for the printer (45 minutes) - Teacher checks understanding and addresses student questions, cleanup (5 minutes) Day 3 (55 minutes) - Attendance, review of expectations for today's lesson (5 minutes) - Students continue designing gears on computers. Finished students print their gears and help others while waiting for the printer (45 minutes) - Teacher checks understanding and addresses student questions, cleanup (5 minutes) Day 4 (55 minutes) - Attendance, review of expectations for today's lesson (5 minutes) - Students finish printing gears; those with all gears assemble simple gear trains (20 minutes) - Students answer mechanism and gear ratio questions (10 minutes) - Students set up their mechanisms and have fellow students solve their ratios (15 minutes) - Teacher checks understanding and addresses student questions, cleanup (5 minutes) Rubric and Assessment