Re: Individual HW -Application of Ethics to your project. This individual paper is graded for writing quality (50%) and content (50%) and is worth 20 points, see rubric on Bblearn for grading details. The paper must be uploaded into BBLearn in essay format by the due date specified on bblearn. Assignment In this paper, you will be analyzing the ethics around your design and relate it (hypothetically) to one of the following five categories: public safety and pubic welfare, conflict of interest, ethical engineering/fair trade, international engineering ethics, and data selection. You must select one of the case studies and identifying the relevant ethical issues. Your paper must be 3-5 pages single spaced and have the following sections: 1. Project and Scenario Introduction 1.1. Brief Introduction of your project. 1.2. Identify your primary ethical scenario and additionally describe: - What are the relevant facts of the scenario? - What missing information is not provided that you would like to know? 1.3. Who are the applicable stakeholders for this scenario? (this may differ from your actual stakeholders) 2. Ethical Codes and Theories 2.1. Identify relevant professional codes of ethics related to your scenario that you have chosen. 2.2. Identify relevant ethical theories related to your scenario. 3. Alternatives Generation and Comparison 3.1. Identify at least two alternative actions to your scenario - What are the consequences to each action? 3.2. Discuss how this scenario and your alternative actions might affect the stakeholders you have identified in section 1.3. 3.3. Evaluate those alternative actions by applying the professional codes of ethics and ethical theories - Note: each could have competing reasoning based on the code/theory selected 4. Action Selection and Justification 4.1. After carefully evaluating your options (apply the professional codes of ethics and ethical theories), select the best course of action. 4.2. Justify your decision thoroughly. Page 1 Ethical Scenarios1: (1) Public safety and public welfare: Public 1: You have been promoted to team lead of your project. Because of budget concerns raised by the chairman of the company, the team has been unable to hire a sufficient number of qualified individuals to perform quality assurance/inspections that will impact the safety and health of the public. This makes it difficult for the current quality assurance/inspectors to do a good and thorough job. At the same time, a new and tougher design code was adopted by the company that you working for/with. While this code promotes greater public safety than the last one, it also contributes to the difficulty inspectors have doing a good and thorough job. As a result, you set up an appointment with the chairman of the company to discuss both of your concerns. The chairman, agrees to hire additional code officials for the team on the condition that you agree to permit certain specified projects under construction to be inspected under the older, less rigid enforcement requirements. Should you agree to concur with the chairman's proposal? --adapted from NSPE Cases No. 98-5 Public 2: You are an engineer on your team who has been tasked with designing a specialized software package to aid in your design with respect to the impact on public health and safety, such as those that control air and water quality. Testing the software is part of the design process. Because of this, you conduct extensive testing and find that the software is safe to use under existing standards. But you are aware that new draft standards are about to be released by a standard setting organization-- standards that the newly designed software may not meet. You could suggest that the company and its client perform more tests on the software to see if it meets these new safety standards. Such tests would determine whether the company should move forward with the use of the software. But the client is eager to move forward and the company is eager to satisfy its client and protect its finances and existing jobs. Doing the tests would be extremely costly and delay the project at least six months. This would put the company at a competitive disadvantage and cost the company a lot of money-- putting the goals of protecting its finances, existing jobs, and pleasing the client in jeopardy. Testing would also result in a significant rise in the product/service price to the customer during the six months the new testing would delay the project. But at the same time, the management of the company wants to be sure that the software is safe to use. The company requests your recommendation concerning the need for additional software testing. What should you recommend? --adapted from NSPE Cases No. 96-4 1 Adopted from the NSPE BER and modified into scenarios from the discussion cases presented on the Online Ethics Center. Page 2 (2) Conflict of Interest: Conflict 1: One of your tasks on your design team is to perform a study and recommend the best location for your project. The choices have been narrowed down to two parcels of land. The first parcel is undeveloped and is owned by a person who plans to build a second home there. The second parcel, a developed piece of land, is owned by you. Because of this, you inform the County of your ownership of the second parcel of land, then go on to recommend that the County build on the first parcel for the following reasons: (1) it is a better location from an engineering standpoint, and (2) it would be cheaper to acquire the land. Should the County accept your recommendation, knowing of your property ownership? --adapted from NSPE Case No. 88-1 Conflict 2: You have been tasked by your team to conduct a study regarding the construction of your project. The client is considering building the project in an area next to your neighborhood. Upon learning this, you advise the client that your home is near the proposed project, and that this could represent a conflict of interest. But, the client retains your team’s services anyway and you then conduct the study and ultimately recommend the construction of the project – which was just completed. Is there a danger that your recommendation may have been biased? Did the State act appropriately after your disclosure? Despite the disclosure, was there still a conflict of interest? Were you morally required to do more than disclose the potential conflict of interest? --adapted from NSPE Case 85-6 Page 3 (3) Ethical Engineering/Fair Trade: Fair 1: You just left your company that you are working on the current proposal with to go and work for a competitor company. The project on which you were in charge of while at the first company was virtually completed before you left, but you did not sign or seal the construction/build documents before leaving. Bernard, your old boss, requests you to sign and seal the drawing packet. What are your obligations with respect to the work he left behind? Can you refuse to sign or seal the construction documents? Can you ask company A to pay you for signing the documents? --adapted from NSPE Cases No. 96-3 Fair 2: Your team has submitted preliminary data to the client so they could include that data in a proposal intended to secure additional funds for the project. During this time, the client held many informal discussions with your company, leading the company to believe it would be awarded the contract if the project were approved. Several months later, the client told your team that the public and private funding it had received would not be sufficient to fund the full scope of the project. The firm was then asked to evaluate the possibility of a more limited scope of the project. Believing that you would be awarded the design contract, your team investigated the possibility of a more limited project--at its own expense of several thousand dollars--and submitted a revised proposal to the agency. At this point, what is the client’s obligation to your company? What does your company have a right to expect from the client? Subsequently, the chief engineer that works for the client informed you that it had turned over all of your data to a second company and was conducting initial negotiations with that firm. The chief said that if these negotiations fell through, the agency would contact you for negotiations. Having received your data, the second company was aware of your team’s involvement in the project – who neither contacted your company for discussions of the project nor for its earlier submissions to the State agency. How should your company respond to the State engineer's information? What should your company do? What obligation does the other company have to you, if any? --adapted from NSPE Case No. 77-5 Page 4 (4) International Engineering Ethics: International 1: You are a legally recognized engineer here in the United States, a resident in your home country, and an NSPE International Member. Assume your project with your American company has a client in your home country. Under the laws of your home country, it is legal for individuals to provide cash payments to public officials in order to obtain project assignments. In fact, doing so constitutes a tax deduction for you back home. Because of this, you want to provide cash payments to public officials in your home country to get the project, but you know that this practice is against NSPE's code of ethics. Should you proceed? --adapted from NSPE Cases No. 98-2 (5)Data Selection: Data 1: Amory, an engineer, is retained by the City to design a bridge as part of an elevated highway system. Amory retains the services of Carroll, a structural engineer, with expertise in horizontal geometry, superstructure design and elevations, to design certain parts of the bridge. Carroll drafts plans for the bridge's three curved welded-plate girder spans, a critical part of the bridge's design. Months later, Amory enters the bridge design into a national organization's bridge-design competition, and it wins first prize. The entry, however, fails to credit Carroll for his part in the bridge design. What, if anything, should Carroll do? --adapted from NSPE Case No. 92-1 Page 5 SAE BAJA BRAKE ANALYSIS [1] Eric Kooinga SAE Mini Baja 2018-2019 – Team 18F08 ME476C-007 Northern Arizona University 11/9/18 Table of Contents Introduction to Brake System Components 1 Brake Analysis of an SAE Baja Vehicle 2 Assumptions and Variables 2 Static and Dynamic Loads 3 Braking Forces 4 Pedal Design and Evaluation 7 Appendix A: Brake Force Calculations 8 Appendix B: Manufacturing Drawings 12 References 13 Introduction to Brake System Components A braking system consists of multiple moving components that convert kinetic energy into thermal energy using friction. For vehicle use, there are 2 main types of braking systems used: drum brakes and disc brakes. Drum brakes consist of a cylinder, or drum, around the axle of the vehicle connected to the hub, which uses brake shoes on the inside of the drum to press against the inside edge of the drum brake using both driver pedal effort and springs within the drum brake. Drum brakes were considered but quickly decided against as the stopping power to weight ratio was not desired for this application. Disc brakes consist of a rotor and caliper, in which the caliper contains two pads that will be compressed around the rotor by a clamping force. Manual brakes were only considered for this analysis as the use of a brake booster vacuum will not lead to an advantage to the team as it would be adding more weight without providing any advantage to the driver in a light weight vehicle. For manual brakes, the force applied by the driver’s foot to the pedal is increased by the pedal ratio to the master cylinders. This mechanical advantage is designed into the pedal, which is based on the distances between the input force, the pivot point, and the location on the pedal which actuates the master cylinders. The master cylinders provide a hydraulic pressure based upon the amount of driver input to the brake lines which lead to the calipers. When this pressure is applied to the calipers, a clamping force gets translated across the caliper to the rotor, which produces thermal energy and leads to stopping the vehicle. For a hydraulic braking system that consists of rotors and calipers, it is recommended one of the two components are floating. Floating rotors are mounted to the hub, but have bushings around the mount in order to adjust to the caliper, opposed to fixed calipers which do not have bushings and are rigid bodies. On the other hand, floating calipers are placed on slider pins and compress to one side of the rotor where the rotors will apply an equal and opposite force back on the caliper. Due to this force, the caliper will slide back to engage the other pad creating an equal clamping force on both sides of the rotor from the caliper. If the rotor experiences a minor deflection, the caliper will be able to adjust based on this deflection. It is important to have a system in place where either the rotor or the caliper is floating, otherwise any deflection or issue with perfect mounting positions will cause brake rub. With this in mind, a fixed rotor and floating caliper design was analyzed. An example of the type of system analyzed is shown below in figure (1). Figure 1. Disc Brake System [2] 1 Brake Analysis of an SAE Baja Vehicle The analysis of a braking system and all its components is rather extensive and requires the use of many assumptions for the vehicle the team is designing towards. This analysis is conducted to find the required braking forces needed in order to have all 4 wheels of the vehicle lock. Once educated assumptions were created, both static and dynamic loading cases were applied to find the required values. These values were then designed for when choosing how to size the brakes properly, a problem that almost disqualified NAU to compete in the previous competition. Assumptions and Variables Most of the assumptions that were used for this analysis included many specifications of the vehicle from the year prior, while some were made based on team goals for this year. Important assumptions made include weight, static weight distribution, max speed, center of gravity height, as well as both average pedal force and max pedal force. The assumptions are outlined in table (1). The factor of safety was found from the Brake Design and Safety textbook by Rudolf Limpert which is published by the Society of Automotive Engineers (SAE) [3]. A factor of safety of 1.20 was chosen for preliminary calculations, but once the spreadsheet shown in Appendix A.1 was created a variable factor of safety was set. The goal weight of the vehicle with a driver was chosen to be 550 lbs and was used in the static and dynamic load case calculations. Another assumption made was the average pedal force. This was found by sitting in a similar position on the floor and applying pressure to a bathroom scale against a wall, and a comfortable amount of force applied by the foot was roughly 30 lbs force. The max force tested was 250 lbs but was not realistic conditions to a vehicle. A realistic max pedal force applied by the driver was determined to be 400 lbf, which was found from NASA’s Leg Strength at Various Knee and Thigh Angles graph which displayed knee angle versus maximum push shown in Appendix B [4]. Other values for assumptions were taken from the previous project’s specifications. Table 1. Brake System Assumptions Knowns/Assumptions Curb Weight Weight w/ Driver Weight Distribution Max Speed (flat) Max Speed (DH) Wheelbase Front track Rear Track Ground Clearance Tire Size Rim Size Avg Pedal Force Max Pedal Force Variable M MT V Vmax wb 2 Value 350.00 550.00 40:60 40.00 45.00 59.00 54.50 49.00 10.50 23.00 7x10 30.00 400.00 Unit lbs lbs front/rear mph mph in in in in in in lbf lbf Pedal Apply Speed Theoretical Deceleration (GVW = 600 lb) Max Pedal Travel Pedal Force/Decel Ratio Pedal force ratio Center of Gravity Height (empty) a Factor of Safety FS 3.00 1.60 5.00 100.00 5.6 to 1 24.00 ft/s g in lb/g in 1.20 The assumptions and knowns provided in table (1) will be used in determining the both the dynamic load case of deceleration and braking force calculations. Static and Dynamic Load Cases The static and dynamic load cases were important in determining how much braking force would be needed to be applied in order to efficiently stop the vehicle. First off, the forces acting on a nondecelerating vehicle had to be calculated as a static load either at stand still or moving at a constant velocity [3]. Since our vehicle based on assumptions of past years, the static weight distribution is 40% in the front and 60% in the rear. Since we know the weight of the vehicle, it was relatively straightforward to find the static axle loads for front and rear. The relative static front axle load is given by: 1−Ψ= 𝐹𝑧𝐹 𝑊 (1) where FZF is the static front axle load, W is the weight, and Ψ is the ratio of static rear axle load to the total car weight. The center of gravity must be known in order to determine the application of moment balance as well, which is needed in order to determine a lightly loaded vehicle for careful brake balance analysis and avoiding brake lockup prematurely [3]. The moment balance around the front axle of a static vehicle is given by: 𝑊𝑙𝑓 = 𝐹𝑧𝑅 𝐿 (2) Where L is the length of the wheelbase and lf is the horizontal distance from the center of gravity to the front axle. The horizontal distance was also found for the rear axle defined as lR. Once the static vehicle load case was found, the dynamic loading case was applied. When the brakes are compressed, the torque created by the brakes is resisted by the tire where it touches the ground. Although the brake design goal is to lock all 4 wheels, the brake performance must be able to perform much under the goal in order to provide efficient braking while racing. Before the wheels lock up, the force is a direct function of the torque produced by the brakes at the wheels [3]. The front axle dynamic normal force is given by FzF,dyn and equation (3) shows the application of moment balance about the rear tire to the ground contact point: 𝐹𝑧𝐹,𝑑𝑦𝑛 = (1 − 𝛹 + 𝑥𝑎)𝑊 (3) Where a is the deceleration in units of g, and found by dividing the total braking force by the weight. The value 𝑥 is the center of gravity height divided by the wheelbase. When calculated the deceleration was about 1.6 g’s, and was used to determine dynamic axle loads while decelerating under braking. Figure (2) shows some of the forces being analyzed in the dynamic load case. 3 Figure 2. Dynamic Load Forces [3] In congruence with the front axle dynamic force, the rear axle moment balance about the front tire to the ground is given by: 𝐹𝑧𝑅,𝑑𝑦𝑛 = (𝛹 − 𝜒𝑎)𝑊 (4) Once these dynamic forces were found, optimum braking forces were found by utilizing the braking traction coefficient. More detail to these forces were found using hand calculations, and then plugged into excel for reassurance. This is shown in Appendix A. Braking Forces The braking forces were calculated on an excel sheet with multiple input parameters including rotor sizes for front and rear, caliper sizes and number of pistons, master cylinder bore diameters, tire sizes, pads used (coefficient of friction), balance bar proportioning, and pedal ratio. By creating numerous inputs, it allows the user to fine tune each component for both front and rear in order to reach the required braking force found using the dynamic vehicle load cases above. With a factor of safety of 1.20, the 4 wheel lock force required is about 1302 lbf. This was found by hand as well as in excel and inputted as a minimum requirement of braking force needed to achieve. The calculations are shown in Appendix 4A. The forces and pressures being applied to the brakes follow a logical process that will ultimately determine the clamping forces needed to be supplied by the caliper to stop the vehicle under quick and dynamic braking scenarios. First off, it is important to understand the amount of kinetic energy the vehicle will have when moving at a rate of 40 miles per hour. The equation for KE is shown below in equation (5): 4 1 𝐾𝐸 = 2 𝑚𝑣 𝑣𝑣2 (5) where mv is the mass of the vehicle (loaded) and vv is the velocity of the vehicle. This is important in determining the deceleration rate and the amount of g’s to stop the vehicle. For simplicity’s sake, the governing equations for determining the proper amount of clamping force needed are shown below. The amount of braking power supplied by the brakes to fully lock the vehicle entails quite a few variables and equations beyond the scope of the report, but the excel contains a more detailed outline of the equations used. The braking force output from the pedal assembly is defined by multiplying the pedal ratio by the force supplied by the driver. Under dynamic braking conditions, the value supplied by the driver will vary drastically based on the situation it is in and must be designed on a varying scale to achieve the desired results. Average pedal force was reconstructed using a bathroom scale up against a solid rigid body, with the driver being braced. This force was found to range from 30-40 lbf, while a maximum driver pedal force achieved was 230 lbf. This is not a very accurate experiment for this application but gives a good estimate of to what forces can be seen by the pedal assembly. Once the braking force of the pedal assembly was calculated, a governing equation used based on the master cylinder piston bore area determines the line pressure. This is shown as a relationship below: 𝑃𝑚𝑐 = 𝐹𝑏𝑝 /𝐴𝑚𝑐 (6) The master cylinder pressure is the relationship of force over area, where the pressure is assumed to be constant through the lines to the calipers, equating the pressure supplied to the calipers to the pressure at the master cylinder [3]. From here, the force supplied from the caliper is found by taking the pressure found at the caliper and multiplying by the piston area of the caliper. This will give the clamping force supplied by one caliper but must be multiplied by a factor of 2 as the clamping force is generating by both halves of the caliper body [5]. The force of friction must be considered between the rotor and pad, which was an assumption of 0.4 based on data found regarding coefficients of friction between steel rotors and BP-20 composite pad material [6]. The relationship below shows this coefficient of friction being applied to the clamping force: 𝐹𝑓𝑟𝑖𝑐𝑡𝑖𝑜𝑛 = 𝐹𝑐𝑙𝑎𝑚𝑝 ⋅ 𝜇𝑏𝑝 (7) The torque of the wheel must be compromised by the braking system, meaning the force of friction multiplied by the effective radius of the rotor must be equal to or greater than the wheel torque, and can be found utilizing equation (8) shown here: 𝑇𝑟 = 𝐹𝑓𝑟𝑖𝑐𝑡𝑖𝑜𝑛 𝑅𝑒𝑓𝑓 (8) The torque of the wheel and tire must equate to the torque generated by the rotor, therefore set a synonymous relationship is set up between the two different torques. Another important characteristic in determining braking force is the amount of slip generated in order to react to the torque in the rotating assembly [5]. This is found by creating a variable for the force between the ground and tire, which 5 assumes friction between the tire and the ground, and then is a function of the effective rolling radius of the tire. This relationship is shown below in equation (9): 𝐹𝑡𝑖𝑟𝑒 = 𝑇𝑡 /𝑅𝑡 (9) This process up to this point is determining the braking force required considering a single wheel brake assembly, in which is not the case for Baja where the team is designing for a set of 3 brake assemblies including outboard/wheel brake assemblies in the front and an inboard/gearbox brake on the rear. Since the torque of the output on the gearbox is still unknown, it is assumed to be consistent with the wheel torque applied but will be fixed once this is known. Once the drivetrain team knows this, it can be updated easily within the excel file. With this kept in mind, the total braking force was the force of the tire multiplied by a factor of 3. This takes assumptions that include a consistent and ample amount of friction between the tire and ground, as well as a large enough contact patch to do so. Table 2 below shows the summary of results comparing last year’s braking variables and final braking force to the new recommended design with variables and total braking force required to lock all four wheels. The values found for this use the excel brake force calculator shown in Appendix A. Table 2. Braking Force Calculation Results Old Car 52 New Car 44 Master Cylinder Bore 0.5 in 0.625 in Caliper Piston Size 0.79 in2 1.23 in2 Rotor Size 7 in 8 in Tire Size 23 in 23 in Pedal Ratio 2.4 5.6 Pedal Force Required to Lock (with factor of safety) 191.43 lbf 71.7 lbf As seen in the table of results above, the required for the lock all 4 wheels on the previous car 52 would have taken nearly 200 pounds of force in order to do so. The new design will only need about 72 pounds to reach the same goal. This also assumes a factor of safety of 1.20. The new design would utilize primarily Wilwood braking products. This includes two 5/8” bore GS Compact Remote master cylinders, three GP200 Calipers, 2 sets of BP-20 Pads, and custom in-house 8” steel rotors. This design would also be utilizing a bias bar or balance bar set up, which would be able to adjust the amount of stroke the pedal applies to each of the master cylinder, therefore proportioning the amount of braking force from front to rear. This will be very useful in tuning the braking system to allow all 4 wheels to lock consistently for the tech inspection. 6 Pedal Design and Evaluation Once the known pedal forces were calculated, the design process started on the pedal assembly. A few types of systems were thought about, and due to space requirements 2 types of designs are being considered. First type of design is a floor mount design with master cylinder’s being actuated behind the pedal. The second type of design includes a top mounted pedal assembly to allow for more space in the front nose of the vehicle for the steering rack and pinion. Currently these two designs are still being considered as the team is now transitioning into creating the CAD assembly together. The advantages to running a floor mounted pedal include lowering the vehicle’s center of gravity, having mounting positions readily available based on the 4130 tubing already in place, as well as more sturdy for a pedal assembly as the forces acting on the pedal by the driver are towards the floor of the car. This means forces are acting towards the mounting on the ground rather than opposing all the mounting that would be required for a top mounted pedal [3]. The team is striving to make the floor mounted pedal assembly shown in figure (3). Figure 3. Floor Mounted Pedal Assembly The advantages to running a top mounted pedal would primarily be to save space as well as having easier access to the master cylinders in which would make bleeding the braking system easier. A major disadvantage to a top mounted pedal, which is not shown in this report, is that it requires quite a bit more mounting towards the top of the nose of the vehicle. This not only adds more weight than it is currently, but also must be designed stronger than a floor mounted pedal as the forces applied oppose the mounting position. Finite element analysis (FEA) must still be performed on the pedal assembly to ensure it will not fail for the duration of the competition. This will be conducted along with a top mounted pedal within the near future. 7 Appendix A: Brake Force Calculations 1A 8 2A 9 3A 10 4A 11 Appendix B. Other materials used [4] 12 References [1] A. Leanse, “How Disc Brakes Work,” YourMechanic Advice, 30-Nov-2015. [Online]. Available: https://www.yourmechanic.com/article/how-disc-brakes-work. [Accessed: 09-Nov-2018]. [2] “Difference between fixed and floating caliper ...,” Quora. [Online]. Available: https://www.quora.com/What-is-the-difference-between-fixed-and-floating-caliper. [Accessed: 09-Nov-2018]. [3] R. Limpert, Brake design and safety. Warrendale, Pa: SAE International, 2011. [4] “Human Applied Forces,” NASA. [Online]. Available: https://msis.jsc.nasa.gov/sections/section04.htm. [Accessed: 09-Nov-2018]. [5] “The Physics of Braking Systems - STOPTECH,” Stop Tech High Performance Brake Systems. [Online]. Available: http://www.stoptech.com/docs/media-center-documents/the-physics-ofbraking-systems. [Accessed: 09-Nov-2018]. [6] “Coefficient of Friction,” Coefficient for Static Friction of Steel Chart. [Online]. Available: http://www.carbidedepot.com/formulas-frictioncoefficient.htm. [Accessed: 09-Nov-2018]. 13 Memorandum The NAU Baja SAE capstone team is the Baja Team client. Baja SAE is a competition of engineering students from across the United States who design and build single-seat all-terrain sporting vehicles to compete in a 4 hour endurance race [1]. The client must meet the SAE requirements to compete, and the vehicle must be a “prototype for a reliable, maintainable, ergonomic, and economic production vehicle that serves a recreational market” [1]. One of the essential tests during the competition is the dynamic brake test, in which the vehicle must begin braking and come to a full stop with locked tires within a certain distance. In order to successfully compete in the endurance race as well as pass the dynamic brake test, the client needs a robust, effective, and lightweight braking system. [1] https://www.sae.org/attend/student-events/ Project Need NAU’s Baja capstone team is dissatisfied with commercially available brake calipers due to their bulk and large caliper distance which requires wide, heavy rotors. Additionally, according to the client calipers available off the shelf range from $150-$200 apiece – a total of $600-$800 for a full set. This expense inflates the overall vehicle cost which is a key criterion judges will look at during the competition. Project Goal Team Baja’s primary goal is to design a lighter weight low cost brake caliper with a smaller grip length in order to minimize the rotor width. In addition, the caliper must cost less than commercially available calipers but maintain enough resilience for a four hour endurance race without cracking or overheating. In the process, the team will explore rotor designs to match the caliper grip, including possible slot designs and different materials. Furthermore, the vehicle must retain full braking capability as outlined in the competition rules. Constraints The final design must be some variation of the caliper brake system and the finished product must meet competition requirements and retain full braking capacity (i.e. the design must pass the dynamic brake test). Additionally the NAU engineering machine shop must be capable of manufacturing the finished design and the design cannot exceed the client’s current caliper weight or cost. Objectives The highest priority of team Baja is to minimize the weight of the design and reduce the distance between caliper pistons so that the caliper can be fitted with a thinner rotor. Additionally, the team will explore design variations in order to find the lowest cost option. The team will accomplish this without compromising the strength of the caliper or rotor so that the risk of over-heating and cracking are acceptably low. The final design must be adequate to pass the dynamic brake test, and field repairs must not be complex or time consuming. Deliverables The team will be responsible for delivering fully dimensioned SolidWorks part and assembly files of the caliper and rotor to the client, as well as a Bill of Materials (BOM) and cost analysis for manufacturing a full set of calipers and back up replacements. Additionally, the team will model the design in Matlab to ensure the robustness and efficacy of the proposed design. Summary The current Baja SAE capstone team is discontent with aftermarket brake calipers due to their bulk, high expense, and wide caliper grip length. In order to fix this problem they require a light weight, high performance brake caliper that is easy to manufacture with available resources and machinery. The cost and weight of the brake calipers will determine the success of the design for the client, but these priorities will likely conflict with the durability and effectiveness of the caliper. The final design must meet all competition guidelines, pass the dynamic brake test, and complete the 4-hour endurance race without overheating or cracking. To accomplish these goals Team Baja will explore different designs to find the most appropriate solution and deliver CAD files, a BOM, and Matlab analyses to the client. Tables Table 1. Summary of project definition and needs statement NEED Aftermarket brake calipers are too bulky and expensive for SAE Baja applications PROBLEM DEFINITION Design a lighter weight low cost brake caliper with a smaller grip length in order to minimize the rotor width. Additionally, the caliper must cost less than commercially available calipers but maintain enough resilience for a 4-hour endurance race without cracking or overheating Objective 1. Lightweight caliper 2. Small grip distance 3. Inexpensive 4. Easy field repair Basis for Measurement weight of caliper distance between caliper pistons manufacturing cost for 8 calipers and rotors* time to replace caliper in field braking distance Temperature reading on brake fluid Units kilograms millimeters USD minutes 5. Retain braking capability meters 6. Brake fluid will not degrees kelvin overheat during 4-hour endurance race 7. Rotor will not crack during Visual inspection for cracks millimeters 4 hr. endurance race The team will test objectives 6 and 7 under competition conditions in 4-hour endurance race. *So that each wheel will have one replacement caliper/rotor Constraints Engineering machine shop must be capable of machining parts. Objective 5 must meet competition requirements during dynamic brake test. Name: Ethics Rubric Exit Grid View List View Incomplete Needs significant improvement Novice Competent Proficient Exemplary Identification of Ethical Issue(s) 1.26 (6.30%) 0 (0.00%) No description of ethical issues mentioned 1 (5.00%) Little or incorrect description of ethical issues, ideas are vague. 1.5 (7.50%) A brief, yet not 100% complete description identifying ethical issues. 1.74 (8.70%) Describes variety of ethical issues, but does address in detail. 2 (10.00%) Thoughtfully identifies and describes a variety of ethical issues. Identification of Stakeholders 1.26 (6.30%) 0 (0.00%) No description of stakeholders or interests 1 (5.00%) Identifies at least one stakeholder that may be affected, overlooks main stakeholders and their interests. 1.5 (7.50%) Identifies two more more appropriate stakeholders and highlights some of their interests. 1.74 (8.70%) Describes a variety of stakeholders but does not give a full reflection on their interests 2 (10.00%) Accurately identifies several stakeholders and meaningfully reflects on their interests. Ability to identify Facts Present and Missing 1.26 (6.30%) 1.74 (8.70%) 0 (0.00%) no mention of existing or missing facts 1 (5.00%) Describes very few facts of missing or present information. 1.5 (7.50%) Highlights several points of information present and missing but does not give full description of importance 2 (10.00%) Thoughtfully identifies several facts both present and missing and reflects on the overall importance. Ability to identify Codes and Cannons 1.26 (6.30%) 1.74 (8.70%) 0 (0.00%) no mention of codes and cannons 1 (5.00%) Mentions one code or cannon applicable, no reference to those that are not 1.5 (7.50%) Identifies most relevant codes and cannons but has basic understanding of importance. 2 (10.00%) Identifies all relevant codes and cannons, high regard of importance Alternative Generation and Comparison 1.26 (6.30%) 0 (0.00%) No mention of alternatives 1 (5.00%) Considers at least one alternative without regard to comparisons 1.5 (7.50%) Highlights 2 or more alternatives and compares them thoroughly. 1.74 (8.70%) Identifies 3 or more alternatives but lacks significant comparison between them 2 (10.00%) Accurately identifies 3 or more alternatives and describes meaningful comparison between them. Action selection and Justification 1.26 (6.30%) 1.74 (8.70%) 0 (0.00%) no action mentioned 1 (5.00%) Has difficulty identifying appropriate course of action and is unclear on justification 1.5 (7.50%) Describes an appropriate course of action but only addresses basic justification 2 (10.00%) Provides meaningful course of action and justifies choice with well-rounded case. Spelling, grammar and punctuation 0 (0.00%) No regard for correct spelling, grammar and punctuation. 1 (5.00%) Little to no proofreading. 1.26 (6.30%) Many errors in spelling, grammar and punctuation 1.5 (7.50%) Correct spelling, grammar and punctuation. Some recurring errors noted 1.74 (8.70%) High regard for correct spelling, grammar and punctuation. Only minor errors noted. Clear use of proofreading 2 (10.00%) Memo is nearly free of spelling, grammar and incorrect punctuation. Format 1.26 (6.30%) 0 (0.00%) No table or memo formatting used. 1 (5.00%) Little regard for correct formatting of a memo or table. Did not use paragraphs to build ideas. 1.5 (7.50%) Followed memo format. Missing 1-2 sections, or sections were not executed correctly. 1.74 (8.70%) Format of memo or table is nearly correct. Minor adjustments needed. 2 0.00%) Correct memo format, yet still provides information in paragraphs that build from one another. Correct table format. Table supports the writing Ability to identify Facts Present and Missing 1.26 (6.30%) 1.74 (8.70%) 0 (0.00%) no mention of existing or missing facts 1 (5.00%) Describes very few facts of missing or present information. 1.5 (7.50%) Highlights several points of information present and missing but does not give full description of importance 2 (10.00%) Thoughtfully identifies several facts both present and missing and reflects on the overall importance. Ability to identify Codes and Cannons 1.26 (6.30%) 1.74 (8.70%) 0 (0.00%) no mention of codes and cannons 1 (5.00%) Mentions one code or cannon applicable, no reference to those that are not 1.5 (7.50%) Identifies most relevant codes and cannons but has basic understanding of importance. 2 (10.00%) Identifies all relevant codes and cannons, high regard of importance Alternative Generation and Comparison 1.26 (6.30%) 0 (0.00%) No mention of alternatives 1 (5.00%) Considers at least one alternative without regard to comparisons. 1.5 (7.50%) Highlights 2 or more alternatives and compares them thoroughly. 1.74 (8.70%) Identifies 3 or more alternatives but lacks significant comparison between them. 2 (10.00%) Accurately identifies 3 or more alternatives and describes meaningful comparison between them. Action selection and Justification 1.26 (6.30%) 1.74 (8.70%) 0 (0.00%) no action mentioned 1 (5.00%) Has difficulty identifying appropriate course of action and is unclear on justification 1.5 (7.50%) Describes an appropriate course of action but only addresses basic justification 2 (10.00%) Provides meaningful course of action and justifies choice with well-rounded case Spelling, grammar and punctuation 0 (0.00%) No regard for correct spelling, grammar and punctuation. 1 (5.00%) Little to no proofreading. 1.26 (6.30%) Many errors in spelling, grammar and punctuation. 1.5 (7.50%) Correct spelling, grammar and punctuation. Some recurring errors noted. 1.74 (8.70%) High regard for correct spelling, grammar and punctuation. Only minor errors noted. Clear use of proofreading 2 (10.00%) Memo is nearly free of spelling, grammar and incorrect punctuation, Format 1.26 (6.30%) 0 (0.00%) No table or memo formatting used, 1 (5.00%) Little regard for correct formatting of a memo or table. Did not use paragraphs to build ideas. 1.5 (7.50%) Followed memo format. Missing 1-2 sections, or sections were not executed correctly. 1.74 (8.70%) Format of memo or table is nearly correct. Minor adjustments needed. 2 (10.00%) Correct memo format, yet still provides information in paragraphs that build from one another. Correct table format. Table supports the writing Professional Register 1.26 (6.30%) 0 (0.00%) Unprofessional writing 1 (5.00%) Heavy use of colloquialisms and hyperbole. 1.5 (7.50%) A number of colloquial phrases and hyperbole that need to be improved. 1.74 (8.70%) Nearly free of colloquial writing or hyperbole. 2 (10.00%) Memo avoids the use of conversational or colloquial phrases and eliminates instances of hyperbole Clear and Concise 0 (0.00%) Writing is not understandable. 1 (5.00%) Ideas can barely be understood 1.26 (6.30%) Ideas can be understood after carefully re-reading and deciphering your sentences. Writing clarity and conciseness can be improved throughout 1.5 (7.50%) There are a number of instances of unclear writing or redundancies. Clarity or conciseness needs to be improved. 1.74 (8.70%) Nearly free of vague ideas/pronouns or redundancies. Writing is mostly clear and concise. 2 (10.00%) Writing is clear. All ideas are clearly developed and there are no vague pronouns are phrases. There are not redundancies. Name:Ethics Rubric Exit
Purchase answer to see full attachment