Design Issues Paper Accessible Manufacturing Design Team 2 Felix Adisaputra Jonathan Brouker Nick Neumann Matt Prewett Li Tian For engineers their first priority is always to design a device that will accomplish the task that has been assigned to it. There are almost always other issues that need to be considered and designed for also. Some of these issues are the lifecycle of the product being designed, how accessible the device is to its users', the liability the engineer has, and how safely the machine operates. In today's modern world information is readily accessible to consumers. Therefore, if a product is going to be successful taking into consideration such issues is vital to the success of the product otherwise, the product might end up being the next Toyota brake recall. Product Lifecycle Management Society is beginning to take more responsibility for the disposal of used products. Recycling is becoming more commonplace and in the case metal recycling, very profitable. The ribbon cutter has a simple function to fulfill so it assumed that the machine will not become obsolete from technological advances. The machine is limited in output by the user, so in the interest of making the accessible it also assumed that a higher rate output that could result from more advanced technology is also unnecessary. Also, it has been assumed that this machine will not be mass produced. The parts that were not ordered as pre-made are mostly brackets for holding the machine together. These parts were made mostly from reused scrap metal, and no hazardous chemicals were involved. The ribbon cutter has been built using mostly parts fabricated from steel and aluminum. The parts that were ordered as already assembled include numerous integrated circuits (IC), a guillotine cutter, and a LEGO Nxt brick. A reused computer power supply is being used as the power source of the machine. Using reused parts in the construction reduces the amount of resources consumed during the constructionof the device, but also had the added benefit of reducing costs. When the machine is no longer being used it is assumed that it will be mostly disassembled and scrapped for the high value of the metal used in most of its construction. Batteries. It would also be possible to continue to resuse the power supply. Since the machine is to be maintained by high school students participating in a LEGO based competition is assumed that all LEGO parts could be reused as well. The ICs, LED display, and audio circuits could be recycled as a part of a growing e-waste recycling market. Another design feature was that the NXT brick will be connected to the computer power supply this will have the effect of eliminating the need to change batteries, which would added significantly the amount of waste produced by the machine during its lifecycle. Other than the consumption of electricity to power the power machine is assumed that the machine will not consume any other resources, or produce any other output besides cut ribbon. Product Accessibility This project was designed to be operated by a disabled person. Therefore, the accessibility of this final product becomes the major issue of this whole project. During the design process, this ribbon cutting machine was expected to have all the important features that would help a disabled person to operate the machine. Some essential features that are thought would be useful are 7-segment LED display that will show the input length for the ribbon to be cut, speaker which creates output voice of the length summary of the ribbon that will be cut, and also buttons that would be used to navigate all the important features on the controller box. The 7-segment LED display is designed to make it more accessible for people with difficulties in hearing so they could only read the LED display in order to recognize the length of the ribbon that will be cut. The speaker would also be built in the system for visually impaired users in order for them to identify the resulting ribbon length without the need of reading the LED display. The simplicity to navigate all these essential features described above plays an important role to accomplish the accessibility purpose of this machine. Therefore, buttons will be used in an uncomplicated way to give the disabled user a feeling of the user-friendliness of the machine itself. The accessibility of this overall machine could be improved by implementing additional important features such as a display or voice feedback of the actual length of every ribbon that has just been cut. Therefore, the length accuracy of the cut ribbon could be easilychanged by the disabled user. Another option in order to improve the accessibility of this machine is to build a system that will automatically remove the ribbon if jamming occurs. Disabled users would not need to manually stop the process and fix the jamming problem by themselves since it has already been taken care of by the machine itself. There would be many ways to improve the accessibility of the finalized machine, but as long as it meets the requirements of the desired customer, the machine would be adequately accessible to be operated. FCC Standards for Unintentional Radiators: Wired Emissions One of the standards our project needs to conform to is FCC Title 47 CFR Part 15 specifically parts 15.101-15.107, regarding Conducted limits for class A devices. The FCC divides electronic devices with a clock speed over 9kHz into two categories class A and class B. Class B devices are sold for use in the home while class A devices are for industrial use. Class A is the less stringent of the FCC classifications. Our project is A class a device because it will be used in an industrial setting not in the home. This means that any signals leaving our device via the power cord must be less then 1mv for frequencies up to 1.5MHz and less then 3mV for frequencies higher then 1.5MHz. While it is likely that we could get away with not conforming to the FCC regulations it would be unwise to try. The high frequency noise generated by a switched mode power supply or even our LEGO MINDSTORMS NXT brick could enter the wiring or the building it is being used in through its power cord. The wiring of a building can then act as a large antenna and potentially interfere with other devices. To test our device we can plug it in through a Line Impedance
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