Individual Task 4: Describe what testing has been undertaken on your sub-system of the prototype to confirm that the analysis conducted is valid? What were the results you obtained and did this/n Macquarie Investments Project Title: Space Crane Gearbox 1. Background and Context Following the development of a long list of novel and successful space equipment, the entrepreneur Dr Diasinos has identified a new, exciting and potentially profitable opportunity. Macquarie Investments are currently seeking tenders, which will include a detailed design analysis and a working prototype, for a gearbox that will be suitable to assist with the establishment of a settlement on the moon. This document outlines the requirements that the entrepreneurs have determined are necessary for this device, and a scoring method that they will employ to deem which prototype performs most competently. 2. The Challenge The project challenges students to evaluate their engineering design skills by designing and constructing a prototype gearbox device that will be suitable to be launched from earth and taken to the moon to be used in a space crane. Your team, which consists of no less than three and no more than four students, will tender for the gearbox design. You follow the design process which includes the need for extensive analysis to demonstrate the gearbox performance prior to constructing a prototype to validate your analysis. You will also present your product to the entrepreneurs prior to the competition that will provide you with feedback on the aesthetics and perceived capability of the device. To be the successful tender, your crane gearbox must provide the best compromise in lifting capacity, mass, volume, cost, and efficiency as determined by the scoring rubric provided without contravening the requirements stipulated in this document or future clarifications. 3. Safety 3.1. Health and safety are concerned with the identification, evaluation and control of hazards and thus are of critical considerations in engineering design and product development. Engineers should know that injury and damage to equipment and the environment occurs when the control of energy in a system is lost. 3.2. To protect yourself from the hazards associated with constructing your device, you must wear appropriate personal protective equipment (PPE) such as protective clothing, footwear (closed-toed shoes), safety glasses, gloves and masks where appropriate. Although PPE can protect you, it does not eliminate the hazards and thus does not protect anyone else. Therefore, you must carry out risk assessment of tasks in constructing and running your device, and then submit it to your tutor for approval prior to performing those tasks. Note that your device will not be allowed to be operated on the competition day, and the design report will not be accepted, if the risk assessment of your device is not approved prior to the competition week. Project outline and regulations - 24-3 1 4. Competition Crane 4.1. The competition crane will be used to test your prototype gearbox. It is fabricated using welded steel rectangular hollow sections for its majority. A steel plate is welded to the frame which includes a pattern of 12 holes that will allow the gearbox to be mounted to it as described in 5.3. 4.2. The 0.9m diameter pulley will be manufactured from 12mm thick acrylic with portions machined to reduce its mass. It is anticipated that this component will not weigh more than 6kg. This will include a replaceable aluminium centre that will allow the designated output shafts to be fixed to it with the aid of a grub screw. A CREO CAD model of the crane frame and pulley can be downloaded from ilearn. 4.3. The start position for the mass being raised will be from the moment that the cable's tension is equal to the weight being lifted. It is from this point that the mass must be raised to the defined height within the allocated time. This will be measured using a switch placed below the mass and a second which will be triggered once the desired height is reached. At this point the motor will be switched off for 1 second and then reversed at the same speed as that with which it was raised. 5. Prototype requirements 5.1. Each team must present only one prototype design device that serves to supply the necessary torque and angular velocity at the output shaft to raise a mass 1.2m utilising a pulley that has a 0.9m diameter. The maximum raised mass permitted will be 28kg. The mass must be raised the entire 1.2m height no faster than 10 seconds and no slower than 15 seconds and then lowered in approximately the same time. 5.2. Power will be supplied by an Andy Mark 2.5" CIM motor. For a three person and four-person group, the CIM Motor will be coupled to a 1:100 or 1:48 CIM Sport Gearbox respectively. This will be connected to the input shaft using a direct flexible coupling. The motor can be operated at whatever speed the team deem to be most desirable. During the competition, the power consumed by the motor will be monitored and compared to the theoretical power required to raise the mass at the selected speed to determine the gearbox's efficiency. 5.3. The gearbox casing must be manufactured such that it incorporates a centre casing and casing ends on either side of the gearbox. The gearbox ends must be manufactured from machined 10mm aluminium plates while the centre case will be manufactured as required by your design utilising an FDM printer or bent from 1.0mm aluminium sheet. The centre case external shape must not exceed a rectangular shape of external dimensions 200mm wide and 75mm high. The depth of the gearbox cannot exceed a length of 100mm. Except for any tapped holes used for mounting the gearbox or motor, when assembled, the gear casing must be enclosed to prevent the ingress of moon dust or other contaminants from entering under normal operation and the specified loads. Except for the input and output shafts, no item can protrude beyond the outer faces of the gearbox side plates. 5.4. Each gearbox must be connected to the crane frame or motor mount by only using M5 screws. On the crane frame and any of the 12 5.3mm holes that exist on a 52mm PCD about where the output shaft centre should be on the gearbox mounting plate. The gearbox must also have provisions for the motor to be mounted in a similar way, using any of the motor mount will also include 12 5.3mm holes Project outline and regulations - 24-3 2 that are on a 52mm PCD about where the input shaft centre should be. It is the team's responsibilities to ensure that sufficient screws are used for the connection at the gearbox mount to be able to support the forces and torques acting on the gearbox and to support the weight of the gearbox and motor assembly. When these screws are removed, the gearbox internals must not be exposed to the outside environment. It is also the team's responsibility to ensure that all mounting holes used are accessible with the tools that will be made available at the competition. 5.5. To facilitate the machining of the casing ends, there must be at least 2 additional 4.2mm holes located as far apart to each other and the input or output shaft on each aluminium plate. No machining can be undertaken within a 10mm diameter of these hole centres. The holes may be used to screw the three components of the gearbox casing together. 5.6. With the exception of the input and output shafts, the gearbox must be completely retained within a box that has dimensions of 200mm long, 100mm wide and 75mm high. If your device does not meet the specified geometrical constraints, it will not be permitted to enter the competition. 5.7. Both the input and output shafts must be either a 3/8" or 1/2" hexagonal shaft that can be sourced from Andy Mark to facilitate the easy assembly of the pulley and a coupling that will be supplied as part of the crane. These will both be fixed to the input or output shaft using a grub screw. The input and output shafts must protrude from the gearbox case from opposite ends. The input and output shaft must extend 20mm and 30mm respectively with a tolerance of +0, -1mm past their respective sides of the gearbox end's outer face. This must be positioned such that no part of the pulley contacts the gearbox case or gearbox mounting plate when being operated with the desired load applied. 5.8. In the event that shafts require the use of e-clips, a groove width of 2mm must be used to facilitate the manufacturing process that is available. 5.9. Gearboxes designed by groups of three must only utilise gears to achieve the desired speed reduction. Only groups that consist of four team members must also include a belt or chain drive system. No wet internal lubrication will be permitted. 5.10. All gears, bearings, chains, chain sprockets, belts or belt pulleys must be sourced from Andy Mark. 5.11. Once designs are complete, teams will be required to place an order for the items that they require. All materials and components for the gearbox must be in the approved resources list attached as Appendix B. No other components will be permitted. It is recommended that teams select from the available parts list that will be shared for the quickest delivery. These will be allocated on a first to have designs approved basis. When this list is depleted, orders will be placed for any further required items, but teams must be aware that a minimum of four weeks lead time is required. Only a single order will be placed for the entire class shortly after the order deadline. If any team has not placed an order prior to the specified deadline, they will have to use components that are listed as available. 5.12. Teams must design and construct their device by themselves using the specified materials, components, and methods. To minimise the turning required to manufacture the shafts, it is recommended that e-clips or spacers be used to position gears and bearings on the shafts if required. If e-clips are being used, the groove for the e-clip must be 2mm wide to accommodate the parting tool Project outline and regulations - 24-3 3 used to manufacture the e-clip groove. The diameter of the groove must be 7mm or 10mm for a 3/8" or 1/2" hex shaft respectively. Commonly available components such as LEGO, toy or machine parts are not permitted to be used to manufacture the gearbox. The cost of the components and/or their manufacture must not exceed $300. Teams are expected to include a budget in their design reports to demonstrate that the maximum cost has not been exceeded and for the cost portion of the analysis to be evaluated. 5.13. It is permitted to 3D print components for your device, but each team will be limited to 100gr of printed plastic in total. All 3D printed parts must be printed at the University and only after a tutor has recorded for your group the mass of material required for printing your component. 5.14. Gearboxes that are deemed by the judges to be hazardous to observers or surroundings will not be permitted to run in the final competition. If the judge believes that the device may damage or contaminate the crane, either temporarily or permanently, or is dangerous, the device may be disqualified from the competition. 6. Competition Procedure 6.1. Prior to any attempts on the competition day, the prototype will be scrutineered to confirm that it has met all the requirements stipulated in this document. The geometrical properties of the gearbox, i.e., mass and volume, will also be measured and recorded by the judges. 6.2. Once scrutineering has been passed, teams will be called to the crane separately and according to a random schedule to demonstrate their prototype, teams will be required to secure the gearbox to the crane and motor in less than 2 minutes. Any additional time required to mount the gearbox will be deducted from the time available for demonstrating the device. A select number of tools will be made available as stipulated in Appendix C, any alternative tools required must be provided by the team. 6.3. Prior to any attempt, a team member will be required to designate the mass that will be attempted to be raised and the speed with which the motor should be operated. Once activated, no person may influence or contact the gearbox, crane or mass that is being raised until a judge states that it is safe to do so. 6.4. The available time for each team to demonstrate their prototype will be announced 4 weeks prior to the competition date. During this time, your team will be permitted to make as many attempts as possible with any weight or motor speed combination that the team desire. Only the highest score achieved during the competition will be used. If an attempt is unsuccessful, the team can choose an alternative weight and motor speed for a subsequent attempt assuming that the gearbox is still functional and if the time limitations permit. 6.5. Note that the judges will make the final decision on all matters pertaining to the competition, e.g., safety and performance of the device, and the recorded time. Project outline and regulations - 24-3 7. Evaluation Teams are allowed to have multiple attempts during the allocated time, and the highest achieved score will be taken as the final score for the team. The final score, out of 100, is calculated using the equation below: Score = 30(0.035714L) + 15(−1.1111M + 2) + 15(-961.54V + 1.4423) +15(-0.006667C + 2.00) + 10(2E) + A + P L The maximum lifting capacity achieved during the competition measured in kg. The maximum lifting capacity that will be rewarded is 28kg. M The mass of the gearbox as presented at the competition measured in kg assuming that the mass is between 1.8kg and 0.9kg. A gearbox that has a mass above or below this range will take the largest or smallest value respectively to determine the score. V The volume of the gearbox as presented at the competition measured in m3 assuming that the volume is between 1.50x10³ m³ and 0.46x10³ m³. A gearbox that has a volume above or below this range will take the largest or smallest volume respectively to determine the score. C The cost of producing a single gearbox as presented at the competition measured in A$ assuming that the cost is between A$300 and A$150. A gearbox that has a cost above or below this range will take the largest or smallest cost respectively to determine the score. E The efficiency of the gearbox as it performs at the competition measured as a percentage assuming that the efficiency is between 75% 50% and 25% 0%. A gearbox that has an efficiency above or below this range will take the largest or smallest efficiency respectively to determine the score. A P A score, of maximum value 9, provided by Academics judging the perception that the aesthetics provide of the likelihood that the device will be successful and robust. A score, of maximum value 6, provided by Peers judging the perception that the aesthetics provide of the likelihood that the device will be successful and robust. 8. Manufacturing requirements for gearbox casing ends To reduce the cost and time required to manufacture the gearbox casing ends, the following instructions must be followed. During the machining operation, the raw material must be attached to the bed using the holes stipulated in section 5. The raw material will be provided as an 10mm aluminium flat bar 160mm wide and the required length as long as it does not exceed 220mm. If required, only a maximum of 3 tools can be used during the machining operation. These must be any of the following: • A 4.2mm drill bit (this is the hole size required for an M5 tap) Project outline and regulations - 24-3 5/n

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