Disassembly & Re-Purposing of Unwanted Consumer Electronics
Table of Contents
Motivation & Background
This is an ongoing outreach project started by officers of the Optics Society at the University of Michigan (OSUM) and the Ann Arbor Section of the Optical Society (AAOSA). The idea for the project came about via discussions with members from both optical societies as to what originally got them interested in studying and pursuing a career in science. Many members recall personal experiences with a hobby such as robotics, electronics, model building, or programming - almost all cite a general interest in and curiosity for taking things apart and figuring out how things work at a young age. These hobbies are characterized by hands-on experiences, self-motivated learning, real-world applications, immediate feedback, and problem-based projects. The skills that these types of hobbies build are strongly associated with success and persistence in engineering students. We wanted to recreate this experience for underrepresented elementary school students coming from low-income families that may not have access to the resources that would enable these types of hobbies. We wanted to encourage tinkering and playful exportation with technology outside of the classroom in order to spark this "hobby-like interest" in STEM at a young age. Thus, following the project, we gave the participants all of the parts and tools they would need to continue tinkering at home.
The project was formulated to have three phases: disassembling an item, investigating its components and subsystems, and re-purposing the scrap parts and components to build something new or to demonstrate some aspect of science. We believe the unique combination of these activities can provide young students a safe, hands-on opportunity for exploration and the tools for tinkering with technology while fostering curiosity and motivating learning. We chose to begin by disassembly unwanted point-and-shoot cameras that we acquired for $5/piece or less at local electronics recycle shops. In addition to enabling tinkering with technology, another benefit of this project is its low cost and the ability to utilize e-waste in a sustainable, productive way for outreach. We see this structured project format as a possible tool for STEM educators as well.
Over the course of the Fall 2018 Semester and Winter 2019 Semester, we were able to test the project with two different groups of participants consisting of about 30 students in total from two after school voluntary tutoring and mentoring programs. The first group consisted of second through eleventh grade students at a church’s tutoring program, while the second was fourth and fifth grade students who elected to participate in the project given other activity choices. The total activity time averaged five hours for both cohorts – the first was broken up into two sessions, and the second was scheduled as half-hour sessions held once per week for 10 weeks. We found that the disassembly of unwanted (and even broken) cameras to be an exciting and engaging activity easily accomplished by elementary-age students. Minimal preparation and no understanding of camera technology was required to initiate disassembly. Volunteers, instructors, and nontechnical parents were able to quickly learn and guide as the activity progressed. About 90% of the students reported that they liked the project overall.
The work on this project was presented and published through two conferences - the American Society for Engineering Education (ASEE) North Central Section (NCS) conference in Grand Rapids, Michigan in March 2019 and at Education and Training in Optics and Photonics (ETOP) in Quebec City, Canada in May 2019. At ASEE NCS, the project won the First Place Best Student Paper Award. Copies of both papers can be found below.
ASEE_NSC_Manuscript_Published.pdfThe disassembly and re-purposing of unwanted consumer electroincs - low-cost tools for optics outreach.pdfFocus Group & Project Brainstorming
First Test of project - Southside Church, Jackson, MI
Second Test of Project - Peace Neighborhood Center, Ann Arbor, MI
List of Recoverable Camera Subsystems and Components
Zoom Lens
Description: A motor-driven telescoping helicoid mechanism containing multiple lenses, shutter and iris mechanism. The internal focus usually utilizes a gear motor or electromagnetic actuator.
Project Activity: Touch 3V battery pack leads to motor terminals to extend lens, reverse leads to retract. Use as is or extract components. For disassembly place alignment marks on helicoid lens barrels and keep parts on clean paper plate to ease reassembly.
Internal Lenses
Description: Zoom lens contains several lenses in plastic retaining rings inside of tubular housing. Very high-quality magnifiers.
Project Activity: Once removed from the zoom/focus mechanism, internal lenses can be examined by eye and used as a cellphone microscope or in a camera obscura project.
Flash Unit
Description: Often a simple telescope with zoom capability. Units with two lenses are most common but some may be configured as periscopes with mirrors or prisms.
Project Activity: Extract unit intact as the mechanism can be operated by hand using one or more of the control levers. Can be a relatively easy reassembly activity because the unit has a relatively small number of parts.
Gear Train
Description: Used to advance and rewind film, control lens extension, and other functions. The metal or plastic plate on bottom of this camera has been removed to expose the film transport gears.
Project Activity: Care should be taken to study the gearing and mechanics after bottom retaining plate is removed, as the gears are not fixed in place. Medium difficulty to reassemble.
Flash Unit
Description: Usually found in the upper corner of camera housing. A large capacitor stores charge from a battery, which produces a high voltage. Be sure to confirm that the capacitor is discharged if unit remains on camera during disassembly.
Project Activity: Discharge capacitor and retain flash tube assembly for static electric detector. It is possible for a volunteer to carefully charge the capacitor and demonstrate the flash.
Fresnel Lenses
Description: Found in front of flash unit and sometimes glued to camera body. It concentrates and evenly disperses the light from the flash in the forward direction to illuminate the scene to be captured.
Project Activity: Can be examined with a low-power laser pointer or used as a low-quality magnifier or telescope, art, and decorating circuit animals and junk-bots.
DC Motors
Description: Typically 3 volts and ~1,800 rpm. The largest motor is used to transport and wind film, it may be hidden in film spool or attached to a gear train in camera body. Most cameras contain at least 2 motors.
Project Activity: Observe the function of a mechanism by powering the motor prior to removing it: touch battery leads to motor wires or motor posts. It is interesting to also run the motors on their own. Can be used for several re-purposing activities including junk-bots, gyro-bots, and motor generators.
Gear Motors and Speed Reducers
Description: Some cameras have speed reducers or a gear head motor that can be extracted as one unit.
Project Activity: Excellent item for disassembly and reassembly due to the small number of parts. Contain parts on clean paper plate. Moderate level of difficulty to reassemble.
LCD Screen
Description: Fixed to the circuit board at the top of the camera and used for external display and control of the device.
Project Activity: Different segments of the LCD panel can be randomly displayed by sweeping battery leads across electrical contacts on the circuit board or ribbon connectors.
LEDs
Description: Used for various external indicator lights.
Project Activity: They can be lit by connecting the battery leads to the correct wires or contact points on the circuit board. Note that polarity is important.
Solenoid
Description: Attached to the shutter mechanism or iris. An electric current runs through the wrapped wires which produces a magnetic field that triggers the shutter.
Project Activity: Demonstrate the operation of an electromagnet by attaching the battery leads to the wires ends on the solenoid or conductors. The electromagnet can attract and hold paperclips or staples.
Electromagnetic Actuators
Description: Found inside the telescoping lens tubes. The electromagnetic actuator uses a solenoid to adjust the focus on some cameras.
Project Activity: The focusing mechanism of the lens can be demonstrated by powering the solenoid. It is important to remove actuator with the ribbon conductors attached.
Miscellaneous Parts
Description: A variety of scrap parts are accumulated during the disassembly of the camera and its components. There is a broad spectrum of materials. Discard circuit boards due possible presence of hazardous materials.
Project Activity: Collect, sort, and weigh parts to explore electronic waste issues. Loose parts are useful for art projects and decorating junk-bots.
Re-purposing & Construction projects
Circuit Animals
The simplest re-purposing project idea we came up with is using the scrap parts for either art or building small circuit animals by gluing pieces together. This is most suited to a younger age group and was executed well by second grade students. Googly eyes recommended!
Vibrating Junk-bots
The circuit animals can be taken to the next level of complexity by adding a recycled motor from the cameras and battery pack to nearly any light household item to create a vibrating creature we’re calling a junk-bot. They can also be upgraded to gyro-walking-bots which uses centripetal force from a rotating CD to move around.
Cell Phone Microscope using Recycled Camera Lens
The internal lenses found in a camera’s telescoping zoom mechanism are high quality and function well to simply teach the students about lenses. Other than examining the lenses by eye, they can also be used to create a simple microscope by fixing it to a small camera or cellphone using rubber bands, as shown in the images on the right. Examples of a photos taken of the circuit boards inside the cameras using the cellphone microscope can be seen below. The students enjoyed being able to more closely examine the components and were fascinated by the intricate details of the circuits.
Camera Obscura
The lenses mentioned above can also be used to make a simple camera obscura using construction paper, wax paper, and tape. This project is a great way to help the students better understand how lenses work and how a camera images a scene. The students must determine the focal length of the lens and ensure that the construction paper is cut such that it can rolled into a tube of height equal to the focal length. A circle of wax paper is traced, cut out, and taped to the end of the tube. By placing the “screen” in the perfectly in the focal plane of their camera obscura, the student can obtain a clear image, which is shown in the photo to the left.
Static Electricity Detector
A static electricity detector can be built using the flash unit of the camera. Holding one end of the flash tube assembly by the foil or wire, generate static electricity by walking on carpet, rubbing a wool sweater or balloon. Now to release the charge that has built up, complete the circuit by touching the other wire connected to the flash tube to another object. The tube will briefly light up and although the flash is weak, it can be observed in a darkened room. The more charge you build up the brighter the flash will be.
Simple Motor Generator
The motors from the cameras can also be used to create a simple motor-generator using a battery pack and two motors connected with a plastic straw to power an LED.
Bipolar Electromagnetic DC Motor
For the most advance students, we worked with them to create a bipolar DC motor to further investigate electromagnetism.
Ref: Matsumoto, Y., Sakaki, K., & Sakaki, M., “Development of a New Method for Assembling a Bipolar DC Motor as a Teaching Material,” The Physics Teacher, 55(5), 293-297 (2017).
Discussion Forum
We welcome all thoughts and feedback on this project – ideas for new items to disassemble, re-purposing projects, and general comments about the project. Please use this discussion forum below to submit any feedback you may have. Thank you for your interest in this project!