Teach Sound with 3D Printed Passive Speaker/Amplifier Part 2

thingiverse

This is part two of this lesson. Part one talks about the initial use of 3D printed passive speakers/amplifiers, characteristics of sound and how to measure sound. Here it is:http://www.thingiverse.com/thing:1724605 In this lesson we will be discussing how students can use the information in part one to design their own speakers. I will also provide examples of their work and talk about some of the problems that came up. Print Settings Printer Brand: MakerBot Printer: MakerBot Replicator (5th Generation) Rafts: Doesn't Matter Supports: Doesn't Matter Resolution: .3 Infill: 10% Notes: Print times vary by style of passive speaker. Some can take an hour some can take three. I would print with a minimum of 10% infill and increase it on the same model to explore density vs sound output. Overview and Background It's important that students complete part one of the lesson for the purpose of background knowledge. They'll be gathering the dimensions of their cell phones by measuring them using digital calipers or a ruler. Then they'll base their designs on those measurements and the principals of sound observed in the part one. Here it is:http://www.thingiverse.com/thing:1724605 Objectives Students will use what they learned in part one to produce a passive speaker of their own design demonstrating their knowledge of the properties of sound. Audience This lesson is designed for 3rd-5th grade students but can be applied to higher grades with a bit of modification. I leave that to you since you know your students. Subjects This lesson covers design principals and measurement. Skills Learned (Standards) Using NY State STEM Standards: Standard 1: Students will use mathematical analysis, scientific inquiry, and engineering design, as appropriate, to pose questions, seek answers, and develop solutions. Standard 5: Students will apply technological knowledge and skills to design, construct, use, and evaluate products and systems to satisfy human and environmental needs. Standard 6: Students will understand the relationships and common themes that connect mathematics, science, and technology and apply the themes to these and other areas of learning. Lesson Plan and Activity Have students begin by measuring their cell phone with the case on if desired and to take note where the sound output on the phone is located. Once the dimensions and sound output are known tell them to start with a base design from some of the examples and begin designing it around the specifications of their phone. 1st Start with making sure the sound output on the phone rests flush to the input of the passive speaker. 2nd Remind student that the sound chamber should provide enough space for the sound to expand. 3rd Make sure they make it their own. It supposed to be portable as one group of students last yeat made one with a handle. Lastly the input for the phone should be very exact so sound doesn't escape and can travel through the sound chamber they designed. Next Steps for more advanced students or to continue the project: Change infill percentage to experiment with depth of sound vs infill percentage How far does sound travel? Which type of passive speaker can be heard from how far away and how does that relate to decibels? But a cover on the output of the speaker (plastic wrap works well) and use sand to demonstrate and physical property of sound Different infill percentages can also mimic different materials and touches on commonalities like why speaker boxes are usually made of wood. Materials Needed Besides the items below a basic understanding of Tinkercad.com is required. Buy filament, a lot of it. Buy one or two digital calipers. These are more precise than rulers.https://www.amazon.com/gp/product/B017KUC6XQ/ref=s9_simh_gw_g469_i2_r?ie=UTF8&fpl=fresh&pf_rd_m=ATVPDKIKX0DER&pf_rd_s=&pf_rd_r=C4MHMKCSP18A32RJ172K&pf_rd_t=36701&pf_rd_p=6aad23bd-3035-4a40-b691-0eefb1a18396&pf_rd_i=desktop Buy a decibel meterhttps://www.amazon.com/Leaton%C2%AE-Professional-Digital-30-130dB-Included/dp/B01CCD6CNG/ref=sr_1_5?ie=UTF8&qid=1471541903&sr=8-5&keywords=decibel+meter Duration of Lesson This part of the lesson can be very open ended. It should take students about 2-3 class periods to finish designing their passive speaker. Preparation Things to focus on during the design process: Using negative space to create the sound chamber Be aware of a resting spot for the phone, the idea is not for the phone it fall into the speaker but for the sound output on the phone to rest inside of it Make sure you measure the phone with the case on to create the input slot After you measure the phone make sure you add some space in every direction so the phone can go in and out with ease, I added about 1mm all the way around It's ok to guide students but remember that they will learn best from their mistakes One input but can have multiple outputs Project Designing your own 3D Printed Passive Speaker/Amplifier Now that your students have finished learning about sound and passive speakers it's time to put them to the test. You can have a contest to see who produces the loudest phone passive speaker. I found having students use their own cell phones got them excited. You can do groups for younger grades and individual for upper grades. Tell them they get to keep the speaker once they are done and you'll have plenty of eager students.