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Final Design Report
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1. 10 4 0 11 1 11 4 2 14 4 3 Concept Generaties _____ ________ _____ 19 43 A CONCE DLA 19 2 CONCO DED Drop 20 3 3 CONCE DEC Prate 21 43 4 Concept DRONE DISK araea E __________ 22 4 3 5 Concept a E A EA 23 03 0 CONCE DEF 24 4 3 7 Extending 5 25 4 3 5 DAP AINE DEVICE _ ___ __ AA 26 5 0 Concept Screening 26 5 1 26 Ble CUSTOMER NAAN NA a AT 26 52 SCV 27 5 2 Data and Calculations for Feasibility and Effectiveness 27 5 3 Concept Development Scoring and
2. 133HS 91 BILL OF MATERIAL DRAWING NO DESCRIPTION MATERIAL 3 Ra 63 2 THRU 4 HOLES 3 11 25 38 BILL OF MATERIAL DRAWING NO DESCRIPTION MATERIAL 67 THRU 2 HOLES 5310 09 19 BILL OF MATERIAL 5020 0215 1 09 008 FUNNEL TRAY COVER LASER CUT Ex NOTES 1 BEND PERFORATIONS PAINT GREEN NI CN PROPRIETARY INFORMATION OHIO UNIVERSITY DATA ENCLOSED HEREIN IS NOT TO BE DISCLOSED a ALL EINISHED RUSS COLLEGE OF ENGINEERING 4 TECHNOLOGY SURFACES 127 SENIOR DESIGN TEAM 8 ATHENS OH USA SPGEROSKG NOREASED LENGHT OF VERTICAL 251 O 25 ___ TITI rocco 3 1 PROPRIETARY INFORMATION OHIO UNIVERSITY DATA ENCLOSED HEREIN IS NOT TO BE DISCLOSED a ALL EINISHED RUSS COLLEGE OF ENGINEERING 4 TECHNOLOGY SURFACES SENIOR DESIGN TEAM 8 ATHENS 5 18 2000SPGEROSKI INCREASED LENGHT OF VERTICAL 25 REY CHECKED Co CH BILL MATERIAL DRAWING NO DESCRIPTION MATERIAL 1 fos o11 1c CATCH TRAY COVER LASER CUT NOTES 1 BEND ON PERFORATIONS 2 PAINT GREEN 2 75 1 75 4 4
3. 2008 Unfortunately machines such as these would be very expensive to design and build or buy off the shelf While the underlying concepts can aid the design process a simpler system is needed in this case The following table Table 3 1 1 uses numbers 1 3 to rate each feature as good to bad 1 being good 3 being bad and 2 being moderate Table 3 1 1 Benchmarking of Products Tablet Counting and packing Machine Weight 2 N po TOTALS 19 Note the lower the number the better the choice The best option between these products is the tablet counter because of its simpler nature However an even simpler device has the potential to be far more suitable for our customer needs There are other types of counting machines that would not work for our customer but the technology should also be taken into consideration For example money counting machines serve a similar purpose see Figures 3 1 3 and 3 1 4 Some machines can count bills while other machines can count coins However the coin counting machines would be inappropriate for our customers needs because of the size and shape of the hardware used Ribao 2008 Figure 3 1 4 Coin Sorter Ribao 2008 3 2 Standards As indicated in the features column we would like this device to be moveable but be able to secure it to the table To be movable we should follow standards for how much weight a person in the workplace should b
4. PROPRIETARY INFORMATION DATA ENCLOSED HEREIN IS NOT TO BE DISCLOSED UNLESS OTHERWISE SPECIFIED DIM TOLERANCES OHIO UNIVERSITY RUSS COLLEGE OF ENGINEERING 4 TECHNOLOGY SENIOR DESIGN TEAM 8 ATHENS OH USA
5. 27 5 3 0 6141 1 1518 8 1165151441 1 707 7 7 57 uc 27 6 0 2 AA 30 7 0 Prototype Design Development and TeSting cscsccscsccscsccccscsccccsccccscsccccsceccecsscccscessecsceccscess 31 7 22225555 AA 31 Ted DESIEN ANAY SIS 32 7 MOCK UPS EXPpErimeEntS TESTINE Pint 35 7 5 Board 35 7 352 Production amp Qualit 5 6 __ ________ 35 7 8 CONS 35 8 0 Design Refinement for 36 8 1 Final Design Development and a 4959 37 9 0 Final Design for Production 38 Sad Operahan BAGAN a AINA ANG 38 9 2 How is it Manufactured and Assembled and What Does it 41 9 2 1 Design Drawings Parts List and Bill of
6. 56 44 10 0 091 1 7 119 9 45 Referente Ssa 49 AA 50 Appendix A Additional 50 Appendix Analytical Structural aa an Ga 51 Appendix C Physical 52 to Need 52 2 ada 52 53 AA PE 54 ______ _ _ _ ___ 55 Gy RESUS aera ada AA AG 56 aba ________ 56 E 56 Appendix D 60 Appendix E Design Drawings 1 0 Introduction Team members are enrolled in the Senior Design course for Mech
7. 5 5 reco BILL OF MATERIAL 1 09 002 1 A STAND LASER CUT ES 21 11 ___________ NOTES 1 BEND UN PERFORATIONS 2 PAINT GREEN ALL FINISHED UNIVERSITY DATA ENCLOSED HEREIN IS NOT TO BE DISCLOSED 3 SURFACES 125 5 5 REMOVED 17 TAB FROM BACK ALLOW e 15 15 2009 ACCESS INSIDE NUTS AND BOLTS 2 LOWERED FUNNEL TRAY MOUNT HOLES 456 oe OHIO UNIVERSITY RUSS COLLEGE OF ENGINEERING amp TECHNOLOGY SENIOR DESIGN TEAM 8 ATHENS OH USA DATE MATERIAL 1 22 2009 14 GA SHEET METAL PROPRIETARY INFORMATION ALL FINISHED DATA ENCLOSED HEREIN IS NOT TO BE DISCLOSED SURFACES KA 55 77 2 57 658058 spccnos Olam LOWERED FUNNEL TRAY MOUNT HOLES dK BILL OF MATERIAL DRAWING NO DESCRIPTION MATERIAL 1 09 003 FUNNEL TRAY LASER CUT NOTES 1 BEND PERFORATIONS 2 PAINT GREEN O 12 INSIDE gt BILL OF MATERIAL KG 1 09 004 1 CATCH TRAY LASER CUT NOTES 1 BEND ON PERFORATIONS
8. 47 First the weight of device was an approximate value set before any design concepts were considered When approached about a preferable weight the Tri State supervisors had no immediate input The weight of 10 pounds was then suggested by Team HandiCats as a target specification to aim toward Unexpectedly the weight of 17 pounds 15 actually much safer because of the added friction it causes between the bottom of the device and the table This added friction keeps the device from sliding on the table during normal operation According to the supervisors this device will only be moved occasionally by the supervisors themselves and 17 pounds 18 well within their physical capabilities Therefore although the target specification was not met the weight of the device 15 not a failure but actually a success unexpected ways as well Second the price of the device was also an approximate value set before any design concepts were considered When approached about a preferable price the Tri State supervisors suggested less than 100 While the final production cost reaches 290 without the additional plugs Tri State remains extremely interested in our product Therefore the expected result of this price jump is that Tri State will simply buy a lower quantity of the devices then they were originally planning This does not mean that fewer employees will be able to use this device Tri State will simply need to space out the work done with the
9. Table 10 1 Product Outcomes in Relation to Specifications Customer Specification Product Achievements Comments Slider board is 18 5 wide with 1 of travel in either direction Given some clearance the required station area for table 96 6 j one device is about 22 Accuracy lt 1 error 0 error Goal achieved 46 gt 4 stations to be 8 stations could be used used 3 x 8 per 3 x 8 table 36 x 1 Usual workers Goal achieved 1 Employees understood can operate with 1 Employees understood operation basic operation within minor training enjoyed doing it Accuracy lt 10 first trials 2 Open job to new 2 Lower functioning employees workers previously successfully used device Accuracy 10 Unable to do work 50 Simplicity and Ease of Operation 2 New employees able to effectively use device The boards and stand are expected to 5 years before any achieve a much longer lifetime Stoppers maintenance inspection or bolts loosening is possible but requires only simple checks 5 years before any maintenance inspection Life Expectancy The metal and plastic boards will hold up lt 1 year maintenance to normal wear and tear More adhesive experience needed or hand tightening of bolts is extent of required maintenance 1 Metal or Plastic 1 Any material Adaptability 2 lt 1 bolt 2 lt 1 bolt length Goal achieved 3 lt 5
10. Ss 2 Ergonomics 16 3 3 2 2 2 sa 3 Quality Control 16 2 3 3 3 3 5 8 4 Productivity 15 3 3 3 3 3 5 2 5 Adaptability 09 1 3 3 3 3 6 Cost 08 3 1 3 2 1 7 Size 05 3 2 3 2 2 22 8 Sustainability 05 3 2 3 3 3 5 9 Mobility 03 3 2 3 2 3 10 Aesthetics 03 1 3 3 3 3 Total Multiplied by Weightings 2 51 2 38 2 69 2 53 2 48 Table 5 3 2 Feasibility Chart The weighting of each criterion for the feasibility chart was determined by interviewing Betty Blankenship the production manager at Tri State Industries The group met and observed each concept The likelihood of the design to meet customer needs was given to each concept on the scale of 1 to 3 where 1 15 least likely and 3 is most likely The weight factor of each customer need was explained in Section 2 1 Using the customer s ranking of the needs and the team s evaluation of the needs the weight factors for each customer need was determined Concept C and concept D were determined to be the most likely concepts to meet the customer s needs based on the feasibility chart These concepts were decided by the group to be further developed A prototype of each concept will be made next quarter to determine which concept will physically perform better 28 Figure 5 3 3 Concept 50 Hole Board Figure 5 3 2 Concept D 50 Hole Rotating Spinner Concept Figure 5 3 1 is 50 hole translating board concept Conce
11. on employee feedback Aesthetics Increase workers focus 0 0 0 0 O 4 0 Concept Generation 4 1 Problem Clarification One of the jobs of Tri State Industries is to count and bag bolts nuts and washers These parts vary between plastic and metal as well as 1 size and quantity per order Each order also varies in its total size In other words the entire order may take months to fill or 1t may take a year or more to fill However the employees or consumers as they are referred to at Tri State have difficulties counting to the specified quantity Therefore simple wooden jigs were fashioned to facilitate the process 11 Figure 4 1 1 Example of bolts washer and nut handle by workers Figure 4 1 2 Wooden jigs originally in use to fill orders The jig in the lower left hand corner of Figure 4 1 2 is currently used to fill an order of 32 bolts per bag The consumers place one bolt into each hole until all the holes are filled Once they are all filled the consumers then flip the jig over to deposit the bolts into a larger bag The bolts are then poured out of the larger bag into a smaller bag for shipping Some consumers even pull each part back out of the jigs one by one and place them into the smaller bag A similar process is followed for the nuts and washers The jig in the upper left hand corner of Figure 4 1 2 1s used to fill the same order of 32 parts per bag but this time for the nuts
12. 140 2 psi while the maximum strain was 0 0016 in in It is important to note that the highest stresses did not occur at the 90 bends where they were expected to occur Instead the maximum stresses developed in spots on the flat vertical surface much higher than the bends This can be seen in Figure 7 2 2 below 4 Maximum Stress Location pa Figure 7 2 2 Stress Analysis Stand 33 Based on this finding as well as the maximum stress being below the yield stress of 53 000 psi the stand alone has a factor of safety of 1 43 for this failure mode In order to further verify the design a model with all of the sheet metal parts was tested This analysis was performed using plate elements and refinement points for better accuracy and simulation time The results of this analysis showed that the highest incurred stress on the model was 8 772 psi with a maximum deflection of 0 02 in Again the maximum stress was much lower than the yield stress of 53 000 psi yielding a factor of safety of 6 04 for the fully assembled device Based on these analyses and the certainty of the parameters and results a factor of safety of 6 should be sufficient for this failure mode The second failure mode of the sliding board fracturing was deemed possible due to the lack of support when fully extended Analysis was run in ALGOR to determine the maximum stress of both a 25 Ib and 50 Ib load on the sliding board For 25 Ib load
13. Betty Blankenship the Production Manager for Tri State Industries The customer s needs statement is developed in Section 2 2 The concept ideas submitted by each team member must meet specific requirements based on the design criteria given by the customer listed in Section 3 3 26 5 1 2 Screening Process Three concept screening processes were done in order to narrow down the concept selection The initial screening process required a list of benchmarking concepts that already existed and a list of concepts submitted by each team member Some of the benchmarking concepts evaluated in the first screening process can be found in Sections 3 1 and 4 2 as well as some concepts submitted by the group in Section 4 3 The concept need requirements developed by interviewing Betty Blankenship were used in narrowing the concept list down to 7 concepts The second screening process evaluated seven concepts that were determined in the first screening process More time was taken to research and further develop these concepts However the concepts were still kept fairly basic in order to save time but still show basic ideas Models of the seven concepts can be found in Section 4 3 The goal of this screening process was to make a decision on two different concepts and determine the feasibility and effectiveness of the concepts with respect to the customer s needs statement 5 2 Data and Calculations for Feasibility and Effectiveness Analysis To determ
14. Table 2 1 2 Collaborative Weight Factors of Customer Needs 0 18 Adaptability 0 09 Sustainabilit Mobility 0 03 Aesthetics Table 2 1 3 shows the hierarchal list of each individual customer need including its collaborative weighting Table 2 1 3 Hierarchal Customer Needs List Safety 0 18 1 1 No sharp edges pinch points quick movements or sticking Ergonomics 0 16 2 1 Improve quality of work for current consumers 2 2 Allow additional consumers to perform tasks Quality Control 0 16 3 1 Must not generate additional error Productivity 0 15 4 1 Improve or maintain productivity for Tri State Adaptability 0 09 5 1 Can be adapted to different sizes shapes of parts 5 2 Can be used with parts of different materials Cost 0 08 6 1 Inexpensive to produce and reproduce Mobility 0 05 7 1 Lightweight 7 2 Able to be locked down Sustainability 0 05 8 1 Low maintenance 8 2 Able to withstand factory settings Size 0 03 9 1 Size appropriate for work space Aesthetics 0 03 10 1 Attractive for consumers to use 2 2 Revised Needs Statement Discussion with the customer also led to the determination that the primary focus of the project should be the ease of the system with a secondary focus on the quality of work In order to encompass these focal points the needs statement was rewritten as Tri State Industries has a need for an improved system to increase the ease of and quality of w
15. and washers The only difference here is that the nuts and washers are placed onto the pegs in the board The jig is then flipped over to deposit the nuts or washers into the larger bag only to be transferred into a 12 smaller bag or the parts are removed part by part It 15 then up to the supervisor to manually check each bag before shipment to assure it has the correct number of parts If there is a mis quantity the supervisor must fix the problem by either adding or removing parts Although the customer receiving the parts only requires Tri State to perform a check for every 1 13 bags the supervisors at Tri State feel that that leaves too much error While the Tri State employees are capable of greater accuracy it greatly depends on their mood each day Therefore there is little to no consistency leaving such a mechanical check of 1 in 13 bags ineffectual Fill Jigs Occupy all Pegs or Holes with Parts Send to Vendor Flip Jig Deposit Parts into Large Bag Supervisor Dump Parts Checks Quantity from Large Bag in all Bags into Smaller Bag Figure 4 1 3 Small parts counting and bagging process flow chart Unfortunately the current process is tedious and difficult or impossible for the employees with limited range of motion or low mental functionality Only a few of the employees are currently able to accomplish the larger orders because they have a greater range of motion and ability to count to larger
16. completely parts could be dropped into the bag prematurely causing possible error the counting process 7 0 Prototype Design Development and Testing 7 1 FMEA To ensure that our design was the best possible to solution to the problem the HandiCats performed a FMEA on the design to see if there were any areas that would need to be redesigned before construction Figure 7 1 illustrates the major concerns we have for the performance of our device These issues would render the device unusable and possibly inflict harm to the user or damage to the environment sticks misalign slips Or tips over Figure 7 1 1 Major Functionality Concerns If the slider board were to become stuck or difficult to move the device could not be used This could be caused by too much friction between the slider and the top board A possible solution for this issue 1s to use a material with a low coefficient of friction like we have with UHMW If this is not enough we may have to investigate lubricants The boards could also stick if the magnets are too powerful We must test the magnets before we permanently install them in the board assembly 31 If the holes misalign the device could not be used because this would introduce too much possibility for error to the system One possible cause of this would be if a part being counted were to not fall through completely and get stuck Another possibility could be that the magnets do not work properly and align t
17. into each hole and during one phase of the operation only one part type bolts nuts or washers are counted e Step 3 Slide the middle board laterally to the left or right about 1 5 pounds of pull are required to overcome the magnets The holes in the middle and top boards will align and the parts will drop through to the funnel The parts then slide down the funnel out the funnel opening and into the awaiting bag Return the middle board to its neutral position The magnets will catch and hold the middle board in perfect alignment for the next run e Step 4 Repeat this process two more times with the two remaining part types Once all three part types have been counted and collected the bag the bag can be removed by simply pulling down and out from the bag clip 40 Figure 9 1 4 Small Parts Counting and Bagging Process Procedure 9 2 How is it Manufactured and Assembled and What Does it Cost The manufacturing of this device is very simple it can be summarized as follows see Figure 9 2 1 43 Machining Cut multiple sheet metal parts at once Cutout Perforations for bends CNC mill all Bending Can be done in a vice by hand with perforations special bending equipment Assembly Bolt together using screw driver and wrench only No jigs required plastic board required parts Figure 9 2 1 Summary of Manufacturing Processes The metal sheets would be cut out p
18. numbers Process errors and delays occur when the employees become distracted or have difficulty removing the parts from the current equipment These failure modes call for a device that can keep the user s attention requires little input force or degree of motion from the user and is simple to use for even the lower mental functioning workers Furthermore the work area used to fill these orders is relatively small and therefore restricts the size of apparatus that can be considered see Figure 4 1 4 13 Figure 4 1 4 Workspace allotted to the process of bolts nuts and washers 4 2 Patent Searching The following are patents that were used during the concept generating phase of the design process Although none are directly applicable the concepts behind their operations are good to keep in mind while generating concepts of our own 1 Tablet Counting and Batching Machines U S Patent 2 781 947 See Figure 4 2 1 specifically details one method for delivering a predetermined number of tablets into a packaging container This method uses differential air pressure either suction or air pressure to replace a physical gate that would allow or restrict the movement of tablets through a chute Figure 4 2 1 Gate system to control flow of tablets through a chute 2 Article Counting Machine with Automatic Control of Discharge Assistant U S Patent 14 3 384 269 See Figure 4 2 2 details a method to automa
19. reach this load 1f the user leans on the board while not seated 51 Table B 1 FEA Analysis Results Max Von Mises Displacement psi in 1 165 3 495 500025 025 1 ae 82 0 37 2 298 6 894 11 824 35 472 2 093 6 279 168 0 41 3 379 21 Table 2 Convergence Justification using Scenario 1 Data Difference Case Load Ib aa 44 35 75 86 0 3 10 0 2 78 Appendix Physical Testing C 1 Introduction to Need There are a small number of situations that affect the small part counting and bagging device SPCaBD that need to be tested 1 order to ensure proper functionality of the counting and bagging process The force applied to the handle of the sliding board must be analyzed in order to determine if the device will bend deflect tip over or move when the force is applied C 2 Background Information When a force 15 applied to an object many different results can occur The object can move bend break or even tip For this experiment the tipping force friction force and moving force will be analyzed Theoretical force values can be determined using the equations below but the experimental force values will be determined using a force gage As shown in Figure C 1 below a tension force will be applied to the force gage that will be attached to the device The applied force will be continually increasing until the device slides on the table the device tips over or until the sl
20. test probe was set at 10N however when testing the force required to slide the entire device across the table the 50N setting was used According to the test probe s specification booklet its resolution at the 10 setting is 0 01N and when set at 50N its resolution is 0 05N Therefore the test probe was 0 57 accurate on the sliding force for the middle board and 1 3 accurate on the sliding force for the entire device C 8 Conclusions From the results above we feel confident that the user will be very comfortable using this device Pulling with a force of 1 75 pounds is equivalent to lifting 3 medium sized oranges or a fifth of a gallon of milk which is reasonable to ask Also this force will not be constantly held but instead only be applied for a few seconds during each operation Furthermore the workers will only use the device sparingly taking multiple breaks throughout the course of a day There is also not going to be an issue with the entire device moving laterally across the table due to the force needed to move the slider The force needed to slide the entire device was almost twice that to move the slider However as a safety precaution we will put a friction pad on the bottom of the device to increase its resistance to motion It s interesting to note that the magnets were rated at 56 1 7 pounds maximum pull by McMaster Carr Therefore 1f after field testing it s decided that the 1 75 pounds 18 too much for the emp
21. we developed a CNC program that involved drilling each hole with a 2 drill bit and then milling out the rest of the hole with endmill We encountered some difficulties in using the CNC because we were pushing the limits of the travel of the tooling Also because the piece was large 12 by 12 and made of plastic we could not just support the piece around the edges If we had the piece would have bowed in the middle under the force of drill This would have most likely have resulted slanted holes and at the worst it could have cracked the piece We had to improvise using scraps of plastic and superglue to create supports that would run down the middle of the part and hold the piece securely to the milling table Another important part of our design was the development of plugs These plugs would be used to 1 unwanted holes so that different quantities could be counted without installing a new board These plugs were done of the CNC lathe so that an ergonomic profile could be place on them and they would all be the same Our first design had to be redone after we tested the prototype plug It was too tall and therefore too top heavy and would fall out of the hole This was part because it could not extend more than 72 below the surface of the top board or it would keep the slider board from moving Also we had too much clearance for the plug to fit in the hole We shortened the plug and made it fit tighter and now it
22. 0 parts 3 lt 50 parts Target Spec 15 6 parts min lt 1 year maintenance experience needed Easy Maintenance Production Rate 20 33 parts min Goal achieved Design Criteria 50 parts min Goal not achieved But supervisors are 101 5 safe to carry 17 lbs and it provides enough friction with table to be stable No sharp corners or All corners edges are i Goal achieved Magnets provide some edges pinch points rounded pinch points nee 221 sticking effect but are easily overcome Safety quick movements are limited large quick and intended for safe operation Stoppers or sticking within movements avoided paka restrict too much motion otherwise any moving parts some sticking present Goal achieved One or two employees Workers must be had to stand up to use this device Ergonomics comfortable during Workers are comfortable however they do not operate the device normal operation for extended periods of time Increase workers Goal achieved Device makes work like a Increased workers focus l focus game Effectively keeps their attention Goal not achieved 100 per device was approximate Tri State is still willing to raise money for more devices 5290 device only Cost lt 5100 per device 357 device with plugs Two goals were not achieved by this product weight and price per device However after careful review the product is a success
23. February 12 2009 from McMaster Carr lt http www mcmaster com 85705kac kjrxh gt Carbide Depot n d Retrieved February 4 2009 from lt http www carbidedepot com formulas frictioncoefficient htm gt 49 Appendices Appendix A Additional Figures Table A 1 AHP Pair Wise Comparison Chart Quality 1 KI a a 1 2 22 333 33 33 Bee 88 88 27 2706 noo too 106 __ _ 62 526 2473 a Ergonomics _ Control 1 00 1 peg 1 06 1 79 2 pon 3 23 3 23 5 26 em 26 24 73 Productivity 064 169 soo 2327 015 adaptability oso oss os too 112 170 17 1392 oo Cost 0 45 0 50 0 50 0 53 0 89 1 00 1 59 1 59 2 63 2 63 12 31 0 08 Mobility 0 30 0 31 0 31 0 33 0 56 0 63 1 00 1 00 1 67 1 67 7 78 0 05 Sustainability 0 30 0 31 0 31 0 33 0 56 0 63 1 00 1 00 1 67 1 67 7 78 0 05 Aesthetics 50 Appendix Analytical Structural Analysis For the analysis of this failure mode the model of the sliding board was cut to represent its fully extended mode This was seen in Figure 7 2 3 in Section 7 2 The model was then imported into ALGOR The analysis was run using two different sets of constraints The first set used for the initial 0 3 in 0 2 in and 0 1 in meshes without mid side nodes consisted of the cut surface being fully fixed The second set used for the 0 2 in mesh with mid side nodes as well as a 0 2 in mesh withou
24. SMALL PARTS COUNTING AND BAGGING DEVICE Team HandiCats Nichole Blackmore Steven Geroski Eric Gillette Bruce Miller Kyle Sink Andy Tompkins 10 June 2009 Abstract The need for the project was to assist people with disabilities in the workplace Team HandiCats worked with Tri State Industries to enhance the process of counting and bagging small parts The following report contains the need benchmarking concept generation and concept selection for the project It also includes the design development and testing design refinement final design description and conclusions Table of Contents 1 0 5 221 1 22 15 Onna 1 Pro ANAL 2 1 0 3 560 __ _ ____ 2 104A OCUIVES 2 1 1 Initial Needs Statement __________ _ 2 151422 NAA 3 2 0 Customer Asse5sMENL aaa AA AA AA LAGA 3 WejghtingofCustomek NGO noes 4 2 2 Revised Needs 20 6 3 0 Benchmarking Standards and Target Specifications csccsccscsccscsecsccsccccsccsccccsccsceccscescescecescesens 7 1 kak KA AA 7 ANG 9 3 3 Target Specifications Constraints and Design
25. all into a bagging device not shown This can be seen in Figures 4 3 1 and 4 3 2 This idea would require that both ideas be made to satisfy each order independently Therefore the slots and rods would be removable so that different quantities and sizes of parts can be processed Figure 4 3 1 Slotted device for bolts 19 Figure 4 3 2 Rods for nuts and washers 4 3 2 Concept B Drop Plate This idea consists of an angled bread board with 50 holes that is set against a solid plate The holes are one inch in diameter to allow a variety of parts to be counted with one device When all the holes are full the operator pulls a lever or pushes on handles that will depress the back plate and separate it from the front Because the plate 15 at an angle the parts will fall back and through the device and into a funnel that will bag parts This idea is shown Figures 4 3 3 and 4 3 4 Figure 4 3 3 Isometric Front 20 Figure 4 3 4 Back 4 3 3 Concept Sliding Plate This concept involves two plates each with 50 one inch holes that begin slightly misaligned The operator will fill each hole with one part until all are full Then the operator pulls the bottom plate so that the holes align and the parts drop down into a bagging device The bottom plate is then moved back into its original position and the process is repeated The device can be seen as an exploded view in Figure 4 3 5 In reality the bottom plate
26. anical Engineering This year long course is three course sequence that will provide a comprehensive capstone senior design experience for mechanical engineering majors The course includes studies in the analytical techniques of design as well as the design construction and evaluation of the performance of an actual engineering system Kremer 2008 The project for the 2008 2009 class 1s to design and build a device to assist people with disabilities in the workplace in accordance with the NISH competition guidelines 1 0 1 Background Information Around 10 percent of the world s population 650 million people live with disabilities However all over the world persons with disabilities continue to face barriers to their participation in society and are often forced to live on the margins of society UN Enable 2008 There will always be people with disabilities and much advancement has been made to make their lives a little easier and enable them to perform better in the workplace Even with these advancements such as handicapped parking the No Child Left Behind Act of 2001 and powered wheelchairs people with disabilities will continuously struggle with performing simple tasks at work Every device made ensures an easier work day for these people People with disabilities often want to work or need to work but have many obstacles that keep them from getting hired Some of these include Inadequate traini
27. bility Status Report people with disabilities account for approximately 21 2 percent of working age people who are currently working This suggests that the need for assistive technologies 15 widespread among the workforce The purpose of this senior design project is to develop a technology to allow people with moderate to severe disabilities to successfully perform simple tasks in the workplace 1 0 3 Scope of the Work The scope of this project is to design build and analyze a system that will assist people with disabilities working in the Southern Ohio region The team will have direct contact with the customer in order to obtain their ideas suggestions and comments throughout the completion of the project Once the project 15 complete our customer will have a functioning device The team will meet the budget allotted in addition to the NISH competition deadlines 1 0 4 Goals Objectives The goals objectives of the project are shown below Assist people with disabilities the workplace Learn how to both manage and lead a team Effectively use project management tools PO Perform background research and benchmarking in order to acquire the information needed to understand the problem and possible solutions Work with customers to fulfill a need Design and build a functioning prototype Effectively document and present pertinent information to both Dr Kremer and the class Submit a completed application and design r
28. curing to stand 2 Middle Board or UHMW PE SD Has holes similar to but opposite of Top Board Two handles on either side provide a place to grip during operation Houses one magnet 3 Bottom Board UHMW PE SD Simple board with large hole cutout in the middle to allow parts to fall through Also provides support smooth surface for Slider Houses one magnet ergonomic angle 16 Gauge Steel Catches and directs parts toward bag 6 Funnel Opening 16 Gauge Steel Directs parts into bag Catch Tray 16 Gauge Steel Catches any dropped parts during counting Ultra High Molecular Weight Polyethylene Ultra High Molecular Weight Polyethylene Static Dissipative Slider It is important to note that the magnets in the slider and bottom board are located such that in the neutral or closed position they align correctly 39 Magnet location in middle and bottom boards held in with adhesive Figure 9 1 3 Board Assembly Closed Position Considering an order of 50 parts 50 nuts 50 bolts and 50 washers this device was intended to work as such e Step 1 Place bag on clip Slide one lip of a zip lock bag through the clip on the funnel opening Stretch the remainder of the bag around the funnel opening e Step 2 One part of one part type is loaded into each of the 50 holes of the top board while the slider 15 in its neutral or closed position see Figure 9 1 3 In other words only one part is loaded
29. d in this manual Figure 1 SPCaBD Overview 62 Setting Up the Device To ensure that the device can be used safely be sure that it is set on a sturdy surface and that it is comfortable to use in a sitting position No clamping mechanism is required though a rubber pad is recommended Using the Device 1 Insert the top of the bag into the bag clip at the top of the funnel opening Make sure the bag is open all the way and the bottom side of the bag is under the funnel opening 2 Ensure that the sliding board is in the closed position A pair of magnets is used to lightly lock the sliding board in the closed position 3 To get the desired number of small parts plug the unwanted holes with the provided plugs so that the desired number of parts is equal to the number of open holes 4 Insert all your small parts into the open holes so there is one part in each hole 5 Once all the holes are filled push or pull the sliding board form either side until it stops All the parts will fall into the bag 6 Remove the bag and repeat steps 1 5 for another bag or keep the bag on and repeat steps 2 5 to fill the same bag with a different type of hardware Note Washers less than 1 8in in thickness could slide between the top board and the sliding board if placed flat on the sliding board Washers should rest on the top board 63 Using the Device cont d Steps 1 3 0 6 6 6 9 64 Maintenance Should the dev
30. e expected to lift According to research there is no standard from The Occupational Health and Safety Regulation OSHA that has a maximum weight limit Fairfax 2008 The National Institute for Occupational Safety and Health NIOSH has developed a mathematical model that helps predict the risk of injury based on the weight being lifted Fairfax 2008 This accounts for many confounding factors Regulations only require task be assessed when there is a significant risk of Musculoskeletal Injury MSI Considering our design will not be lifted very often and it does not have to be moved by the employees with disabilities the NIOSH model is too elaborate for our circumstances We should be able to make it manageable for one person to move without assistance The production manger said it should not weigh more than then 1015 We will use this as our target specification 3 3 Target Specifications Constraints and Design Criteria We translated the customer requirements and engineering standards to target specifications constraints and design criteria in a number of steps We first went to Tri State to ask the supervisors what they needed and looked at the process Unfortunately during our first visit the employees were not present so we could not supervise their work We did however come away with a good basic understanding of the process and began to develop their needs as laid out in Table 2 1 1 We met as a team to discuss goals that we tho
31. e normal operation of the device 7 2 Design Analysis In order to verify the design before the prototype was constructed the team performed Finite Element Analysis This analysis focused on two separate failure modes of the design the failure of the 14 gauge steel stand bending due to a horizontal force and the failure of the UHMW Polyethylene sliding board due to a vertical force The first failure mode of the stand bending was deemed possible due to the lack of side support such as cross members would give For the analysis of this failure mode the model of the stand was imported into ALGOR The model was constrained at various nodes on the horizontal surface constituting the base of the stand This method was selected to produce accurate results if the stand were to bend Forces of 25 165 each 32 were then applied perpendicularly to the sides of the stand is seen in Figure 7 2 1 below There are red arrows that point to the right show where the force 15 being applied and 1 what direction The red triangles at the bottom show where part 15 constrained It can be seen how the part 15 divided up into a mesh in this figure as well These forces simulate a person leaning partial weight on the device Figure 7 2 1 Constraints and Forces Applied to Stand Model The analysis was run at various mesh sizes in order to ensure convergence of the results Upon convergence it was found that the maximum Von Mises stress in the model was 37
32. earch done in the field of magnets however most of this research involves knowing the magnetic field strength of the magnets being used This strength is then used to calculate the force of attraction between the magnets This research can be helpful as background information however the approximate force of attraction between the two magnets being used the system 15 already known Therefore the magnetic field strength does not need to be used to recalculate it The second area of interest is that of the coefficient of friction both between the middle board and top and bottom boards as well as between the stand and the table The research on the coefficient of friction between the middle board and the top and bottom boards proved to be quite useful The material being used for all three boards is Ultra High Molecular Weight Polyethylene UHMW which was found to have a coefficient of friction against itself of 0 12 More About Static Dissipative 2009 Information regarding the coefficient of friction between the stand steel and the table laminated wood was not as readily available It was determined that the coefficient of friction between wood and steel ranges between 0 2 and 0 6 Carbide Depot 2009 however this is a rather broad range and does not specify laminated wood which is likely to incur less friction While the force of attraction between the magnets and the coefficient of friction between the boards are known there ha
33. ed on a wooden table without being locked down 2 The force gauge will be attached to the handle 3 The force gauge will be pulled by hand without holding the SPCaBD with the other hand or securing it in any way 4 When it is pulled one of three things may happen The SPCaBD may tip over slide on the table or the middle plate will slide out to perform the desired function a If the SPCaBD tips over we will record the peak force required to tip the stand from that point and try to reduce the sliding force b If the stand slides on the table before the plate slides we will record the peak force which 15 the static friction force between the metal stand and the wood table We will also record the constant force vs time during the sliding time which is the kinetic friction force From this information we can also calculate the friction coefficients of the stand and the wooden table based on the stand weight c We will then clamp the SPCaBD to the table and pull out the plate and record the peak force This force is the friction force between the plates in addition to the force of the magnets d If the SPCaBD performs as desired the middle plate will slide and we will perform the test as described in c without clamping it to a table We will also perform the tests described in a and b by attaching the force gauge to another 55 part of the SPCaBD to see how close we to the friction force and tipping moment 5 We may need
34. eport to the NISH competition Remain within budget and on schedule for the duration of the project 1 1 Initial Needs Statement According to the NISH competition paraphrased here the initial needs statement 1s There is a need for creative technology that will assist individuals with disabilities to advance in or even enter the workplace These disabilities may include varying levels of physical handicaps or lowered mental functionality The solution may address the disability directly or through indirect means such as adapting their environment 1 1 1 Tri State Industries Tri State Industries is a non profit organization that provides people with disabilities meaningful work experience Tri State s mission statement 1s Our mission is to assist our employees in the development and implementation of employment opportunities and related services as well as provide quality work services and products for our business customers Currently the disabled employees also known as consumers have difficulty counting and bagging small parts such as bolts nuts and washers 2 0 Customer Needs Assessment The HandiCats decided that in order to voice the true needs of the customer it was necessary to make several trips to visit the facility and speak with both the supervisors and the workers themselves The customer Tri State Industries employs people with disabilities to work as consumers Through several visits of observation as
35. fety amp Health Administration lt http www osha gov pls oshaweb owadisp show_ document p table INTERPRETATION S amp p_1d 24876 gt accessed November 4 2008 Featured Banking Equipment Ribao Technology USA Inc lt http www ribaousa com gt accessed November 4 2008 High Speed Tablet and Pill Counter Farma International lt http www farmainternational com gt accessed October 16 2008 Kremer Greg Mechanical Engineering Design 1 Senior Design Course Syllabus 2008 NISH Creating Employment Opportunities for People with Severe Disabilities National Industries for the Severely Handicapped lt http www nish org NISH Rooms DisplayPages Container com webridge entity Entity 5 BOID 5B3289C649A4B65B4AB7 BF230AC4FSA53F 5D 5D gt last accessed November 15 2008 Rights and Dignity of Persons with Disabilities UN Enable lt http www un org disabilities default asp navid 22 amp pid 109 gt last accessed November 15 2008 Statistics about People with Disabilities and Employment US Department of Labor Office of Disability Employment Policy lt http www dol gov odep archives ek01 stats htm gt last accessed November 15 2008 Goc R n d Physics Tutorial Retrieved February 4 2009 from lt http www stafft amu edu pl romangoc graphics M4 M4 frictional force 1 gif gt More About Static Dissipative UHMW Polyethylene n d Retrieved
36. g process that would reduce the labor time reducing the overall cost One of the manufacturing processes that were changed was the way the 50 holes were milled out of the plastic For the prototype we drilled out small holes with a drill bit and milled the rest of the material out to reach the desired tolerance In the final design the initial holes drilled out by a drill bit will be larger This will reduce the milling time by about an hour for each part reducing the overall cost while staying the desired tolerance The initial prototype did not allow clearance in one of the planes for the sliding part We did not notice this until 1t was assembled For the prototype we had to slot the holes of the spacer parts and push them out so that the middle board would have the clearance needed For the final design we reduced the height of the middle board and tightened the tolerance of that dimension to ensure enough clearance for the moving part without slotting any holes The rear support piece was also interfering with the sliding This part was not needed for the final design so it was replaced by two washers to keep the same needed stack up This also reduced the weight and overall cost Parts were getting caught by the bolts holding the funnel into place This was noted by the customer during their trial period On the prototype we cut the bolts On the final design we are reducing the length of all the sheet metal bolts so we still have only two ty
37. he boards incorrectly Or the user will not bring the magnets close enough together to cause them to attract In order for improvements to be made we assigned each failure mode a rating from 1 to 10 with one being the best and ten being the worst in three separate categories probability of occurrence severity of failure and the probability of detecting the failure Table 7 1 1 Failure Ratings Ci Occurrence Severity Detection Total By doing this process we can identify the aspects of the design that need to be addressed by which category has the highest total This total was calculated by multiplying all the factor values together The acceptable threshold was 150 however the ideal would be less than 100 Only the stability of the stand is in the acceptable range at this point with both the stinking slider and the misaligning of holes being well outside acceptable The biggest factor this FMEA 15 the lack of failure being detected These failures will happen quickly and will probably not give signs ahead of time that they will happen From this we see that the greatest threat to the functionality of the device is the holes not aligning To substantiate our claim that failure by tipping or sliding 15 unlikely to occur we tested the model using finite element analysis The results of this test are explained in section 7 2 However these are not the only ways that the device can fail These are simply the most likely to occur in th
38. hed so that the mass of the total product is known Then the consumer fills one piece at a time on the hanging plate Once the weight matches the weight of the desired quantity the consumer releases the bottom plate and empties the parts in a bag The weight will have to be measured with a digital scale because some of the parts are very small and accuracy 15 paramount Figure 4 3 10 shows this idea 24 Figure 4 3 10 Grocery Scale 4 3 7 Concept G Extending Pegs This concept works similarly to Concept B however instead of the back plate dropping back pegs push the parts up out of the holes The parts then fall down the front of the board through a gathering system and are deposited into a bag This 1s displayed Figure 4 3 11 25 Figure 4 3 11 Extending Pegs 4 3 8 Bagging Device A bagging device has not yet been finalized it would have to be slightly different for each concept The use of a funnel will be most likely due to its simplicity However the details behind securely attaching the bag have not yet been discussed 5 0 Concept Screening and Evaluation 5 1 Concept Screening Each device concept submitted was observed by each group member individually The group then had a meeting to discuss each individual s observations and the devices were then compared to the customer s feedback of the need requirements 5 1 1 Customer Feedback Need requirements for the counting device were determined by interviewing
39. hown in Figure 2 1 1 was given to Tri State in order to determine the customer s evaluation of the needs The team s rankings were given to the customer such that the customer could see what needs the team felt were most important Part of our process 15 to access the needs of the project and rank them in order of importance so that we can focus our attention appropriately We have considered the needs and ranked them to the best of our abilities as you can see on the far right side of the table below We would like to ask that you also rank the following needs in order of importance 1 being the most important 10 being the least important Please save your changes and email this back to me at your earliest convenience Also feel free to contact me with any questions Thank you advance Tri State s Team s RANKING RANKING ease of use for consumers e ability to reduce error 4 4 e rate of production e ability to work with multiple materials sizes and quantities cot see Sustainability e low maintenance ability to be easily moved E Aesthetics e attractiveness to consumers Figure 2 1 1 Customer Needs Survey Using the customer s ranking of the needs See Figure 2 1 1 in addition to the team s evaluations of the needs an AHP Pair Wise Comparison Chart was created This chart which can be found in Appendix A as Table A 1 assisted the team in determining the new weightings seen below in Table 2 1 2
40. ice require any maintenance there is a preferred method to dissembling the device 1 Remove four 4 blots on side of device labeled 2 and remove the catch tray 2 Remove four 4 bolts on front of board assembly and remove board assembly one board at a time 3 Remove four 4 bolts from side of device and remove the funnel tray To reassemble follow steps in reverse This is best done with two people but can be done with one Tools needed 1 Flat Head Screw Driver 2 Adjustable Wrench 3 Adhesive Polyethylene compatible 65 66 Appendix E Design Drawings The following pages encapsulate the design drawings that detail our product 67 _____________ MATERIAL 4 09 005 0 Bortom VIEW A 6 os o07 0 7 09 008 0 FUNNEL TRAY COVER EO 8 09 0010 0 1 9 09 0011 0 catch TRAY 11 10 WASHER REGULAR 10 WASHER 12 10 24 UNC 2 LG HEX HEAD BOLT 4 13 HEX 10 24 UNC HEX NUT 4 14 1 4 1 4 20 UNC 1 2 LG HEX HEAD BOLT 15 1 4 20 UNC HEX NUT NOTES 1 SEE VIEW A FUR ASSEMBLY URDER 2 ALL PLUGS SHOWN CLARITY _PROPRIETARY INFORMATION OHIO UNIVERSITY ALL FINISHED DATA ENCLOSED HEREIN IS NOT TO BE DISCLOSED 3 SURFACES 125 a oa
41. iding board moves as desired If either of the first two scenarios occurs the device will 52 need to be redesigned to acquire the desired result If the device slides on the table the friction coefficient between the table and device will need to be increased possibly by adding a different material to the bottom of the device If the device tips some supports may need to be added to the sides to ensure that the device stays upright lt Figure 1 Diagram of Experiment 2009 3 Specific Aims The purpose of this experiment is to determine the assembly s ease of use Depending on the force required to pull or slide the middle plate how easy is the system to operate This pull force will have to overcome any friction present between the plastic boards as well as the magnetic force holding the plates in proper alignment This proper alignment refers to the holes in the middle plate being off center to the holes the upper plate this way the holes do not line up and the parts can rest within the upper holes while lying on the middle plate The plastic chosen 18 Ultra High Molecular Weight Polyethylene UHMW This plastic purposefully has low coefficient of friction similar to Teflon It 15 widely used machinery 85 friction pads to allow quick easy movements It also has very good abrasion resistance to reduce wear and prolong its lifetime For these reasons it is expected that the friction betwee
42. ine the feasibility for a 50 part counting device we first did benchmarking research to see if such machines or devices already exist or have been attempted This research can be found in Section 3 Tri State already uses wooden jigs that can accommodate up to 32 parts This proved that it 1s feasible to develop a device to assist in counting parts Figure 4 1 2 of Section 4 shows the existing wood jigs used by Tri State The goal of this project 15 to further develop and improve these jigs to accommodate 50 parts 5 3 Concept Development Scoring and Selection 5 3 1 Concept Development The goal of concept selection is not to select the best concept but to develop the best concept After the first screening process ideas pulled from observing a large list of concepts were taken and applied to a narrow list of 7 total concepts submitted by each group member Figure 5 3 1 shows the concept development chart used by the group 5 Development Statement Generation Screening Scoring Figure 5 3 1 Concept Development Flow Chart 27 During second screening process the list of 7 concepts were compared and analyzed in a Feasibility chart Table 5 3 2 is the feasibility chart used in determining which two concepts would be further developed into prototypes The chart was designed by collaborating with the customer A B 3 1 Safety 18 3 2 3 3 3
43. ities in the workplace Accomplished The employees of Tri States Industries were very excited to use our product It improved their focus desire to do the work and ability to achieve the appropriate accuracy Furthermore their supervisors are also very pleased with the results after using our device 2 Learn how to both manage and lead a team Accomplished Each team member took control of certain deliverables within the project scope at some point s within the academic year This enabled each of us to learn how to manage the work as well as lead 3 Effectively use project management tools Accomplished Management tools such as the project scheduler in Microsoft were used effectively to plan out project deliverables 4 Perform background research and benchmarking Accomplished Background research was done in the beginning of the project to determine benchmarks that already exist Further research was done as the project progressed and the device s functionality was put to the test 45 5 Work with customers to fulfill need Accomplished As stated before Tri Industries 15 very pleased with the device developed for their workers Communication was held since the beginning of the project and continuous feedback was exchanged between both parties 6 Design and build a functioning prototype Accomplished The prototype 15 fully functional and accomplishes many of its design specifications laid out in previous sections see below for
44. l through into a funnel that directs them into a bag This will have the general form 2 BB 2 Figure 6 2 Final Concept Top View Figure 6 1 Final Concept Isometric View The benefit of a device like this 15 that there 15 little effort required by the user The only input they are required to give 15 a small lateral force to the left or right depending on whichever direction 18 more comfortable for the user to slide the middle slider board left or right one inch A plastic with a low coefficient of friction would do well to further reduce the input force required Not shown here 1s a funnel not yet designed that would catch the small parts after they fall through The funnel may direct the parts to the front middle or back of the device Having the bag in the back of the device to protect it from parts accidently being dropped in the bag However having the bag in the front of the device would allow easier access by the user Further development 15 required to determine the optimum bag location Furthermore in order to simplify the process and ensure proper operation of the device either a stopper or automatic return on the middle slider board is thought to be required Currently a 30 spring system to automatically return the board to its proper starting position holes closed 15 thought to be the best option If the holes are not closed
45. loyees replacement magnets can be found Table C 1 Table of Results Average Ibs Peak Ibs LNM 046 0 64 046 066 _ RNM 048 059 RNM 043 0 37 _ RNM 050 09 _ RM 0 86 158 RM 084 155 _ RNM AVG RM AVG Ll aq 57 Force Force Ib 2 664 1 554 08 0 6 04 212 02 0 0 1 54 Statistics for Latest Force min 0 01106 at 3 240 max 0 7314 at 2 140 mean 0 4662 median 0 4922 std dev 0 16591 samples 72 2 0 25 30 Time 5 Figure C 1 Magnets Force Data Statistics for Latest Force min 5 181E 007 at 2 420 max 1 591 at 3 220 mean 0 7890 median 0 8904 std dev 0 49636 samples 57 25 3 0 35 Time 5 Figure 2 Magnets Force Data 58 1 2 648 3 933 Statistics for Latest Force min 0 02391 at 2 400 max 3 836 at 4 860 mean 3 021 median 3 399 std dev 1 0777 samples 233 Time s Figure C 3 Data for Sliding the Device on the Table 59 Appendix User s Manual The Small Parts Counting and Bagging Device SPCaBD User Manual OHIO UNIVERSITY 60 ADANGER Keep fingers away from device s openings to avoid injury SPCaBD Overview Thank you for using the small parts counter To ensure proper use of the device please this simple manual Figure 1 shows the part names use
46. more detail The prototype is ready for production and implementation outside of its primary customer 7 Effectively document and present pertinent information Accomplished Through the year project presentations have been given that effectively communicated to the other engineering students our design concepts their development and implementation Furthermore engineering notebooks have been documented with all the details of the project as they unfold 8 Submit a completed application and design report to NISH Accomplished A design report was submitted to NISH Although NISH saw improvements that could have been made the project as it applies to the NISH standards was an overall success Moreover a patent will be filed for this design for further development for similar companies around the United States 9 Remain within budget and on schedule Accomplished The budget referred to is the overall budget given to Team HandiCats at the beginning of the project which amounted to 300 Since all the labor was done by Team HandiCats the only costs relative to this project were material costs Given the simplicity of the device the prototype stayed just under budget We were also able to stay within the limits of our project schedule the entire year After delivering the product to the customer for testing for about two weeks we have determined the following characteristics of the device 1 relation to our initial customer specifications
47. n the boards is extremely low u 0 12 Therefore one of the main objectives of the experiment will be to determine the pull force needed to overcome the magnets Rare earth magnets were selected for their high strength to size ratio The magnets are Ultra High Pull Neodymium Iron Boron magnets They are rated at 10 times the strength of regular Alnico magnets approximately 1 7 155 maximum pull However that rated pull force would be directed out normal to the magnet s face It 1s expected that a force perpendicular to its face or a sliding force will be less severe Therefore the experiment will determine that sliding force needed to separate the magnets Once separated by even a quarter of an inch the magnets do not affect each other so further sliding of the middle plate will be unaffected by the magnets This portion of the sliding operation will be purely under the effects of friction As discussed previously this is expected to be low Consequently 1 15 hypothesized that a pull force of about 53 one to two pounds will be all that s required to initially slide the middle plate After that the board should slide freely with little to no effort Figure C 2 Full View of Jig C 4 Significance The two main areas of the experiment at hand involve the field of magnets and the field of coefficients of friction Both areas were researched in order to determine the relevance of past experiments There has been a great deal of res
48. ng and Discouraged from working by family and friends but the largest being No appropriate jobs available US DoL 2008 Jobs for people with disabilities need to be simple and within their limits but also need to push their capabilities The National Industries for the Severely Handicapped or NISH is an organization dedicated to helping these people As defined by the organization NISH 2008 NISH 15 a national nonprofit agency whose mission 15 to create employment opportunities for people with severe disabilities by securing Federal contracts through the AbilityOne Program formerly Javits Wagner O Day JWOD for its network of community based nonprofit agencies Providing employment opportunities to more than 40 000 people the AbilityOne Program is the largest single source of employment for people who are blind or have other severe disabilities in the United States More than 600 participating nonprofit organizations employ these individuals and provide quality goods and services to the Federal Government at a fair price 1 0 2 Purpose of Project People with disabilities often have the same or greater desire to contribute in the workplace as those without disabilities however these individuals are often unable to perform even simple tasks due to their disabilities For this reason assistive technologies are needed to allow people with disabilities to perform more naturally in the workplace According to the 2007 Disa
49. ng Magnetized Conveyer 17 Figure 4 2 8 Rejection System for Inaccurate Fasteners across Magnetized Conveyer Nut Sorting Machine U S Patent 3 613 882 See Figure 4 2 9 details a method for sorting different sized nuts This method would allow a wide range of differently sized nuts or washers to be counted without modification from the Tri State employees Figure 4 2 9 Nut Sorting Machine 18 4 3 Concept Generation Brainstorming was done outside of group meetings by each team member Then meetings would be held to present each idea During these sessions ideas were explained then dissected and analyzed by other teammates In depth detail was not generated during this period Rather allowing other members to question design ideas and brainstorm possible alternatives to general features refined concepts were created A total of seven concepts have been advanced from preliminary brainstorming sessions These are displayed below along with a description of the operation Each of these concepts has been evaluated as to whether they meet our customer s requirements and our target specifications This will be discussed in section 5 4 3 1 Concept A Rotating Devices This idea involves slots and rods that are filled with bolts and nuts washers respectively up to a certain length When the slots or rods have been filled completely the correct quantity has been achieved The device is then rotated so that the parts f
50. o exert A detailed report of the experiment is included in Appendix 7 3 2 Production amp Quality Analysis In order to test the production and quality of the device the supervisors at Tri State were asked to perform a two week trial of the device with two different employees The two employees were both timed and checked for accuracy The first employee a higher functioning employee named Corrinna was able to reduce her time 50 73 and maintain zero errors for the entire two week trial The second employee a lower functioning employee named Ben was originally not able to perform the task With the device he was able to complete the task and maintain zero errors for the entire two week trial Both employees increased production while maintaining the quality of the work 7 4 Prototype Construction 35 During the construction of the prototype a variety of methods were used The fabrication of the stand and other metal parts was contracted out to a plasma cutter to ensure that the dimensions were held The plasma cutter also added perforations to the metal to aid bending the stand and to relieve some of the stresses in the steel The plastic parts were made in house using the CNC milling machine in the Mechanical Engineering Design Laboratory We decided to use the CNC mill over the manual mill because the placement of the holes needed to be exact or there will be overlap which would result in the holes misaligning With the help of Randy
51. ork in the counting and bagging of nuts bolts and washers performed by their employees also called consumers with mental and or physical disabilities The main focus 15 ergonomics of the system such that severely disabled employees who are currently unable to participate in the work will be able to use the system 3 0 Benchmarking Standards and Target Specifications 3 1 Benchmarking Commercially available products already exist for the purpose of counting small items One of which 15 a tablet counter used pharmacies A large amount of tablets and pills can be dropped onto a tray and the machine will release the desired amount of tablets Farma 2008 This design concept could be used in the application of small hardware Bolts nuts and washers are about the same size and shape of tablets This system 15 shown in Figure 3 1 1 Figure 3 1 1 Pill Counter Farma 2008 Another automatic Counting machine 15 the Candy Nut and Tablet Counting and Packing Machine This machine can automatically sort and count parts as well as fill and seal bags This machine can pack one to ten kinds of different hardware parts into one bag It can pack all kinds of small regular or irregular hardware and plastic products such as nails nuts bolts and electronics ECplaza 2008 This machine would make the entire process automatic accurate and fast shown in Figure 3 1 2 Figure 3 1 2 Candy Nut and Tablet Counting and Packing Machine
52. over move when a force 15 applied to the sliding board The second of these tests involved a production and quality analysis 7 3 1 Sliding Board Analysis In order to analyze that the device will not bend deflect tip over or move when a force 15 applied to the sliding board a test was created to determine the force necessary to move both the sliding board and the entire device For the first part of the test a force gauge was attached to the sliding board The force required to move the sliding board between closed and open position was tested for two different scenarios with the magnets imbedded in the middle and bottom boards and without the magnets The maximum force required to move the sliding board was found to be 1 75 lbs with the magnets and 0 75 Ibs without the magnets For the second part of the test the force gauge was attached to the stand of the device The force required to move the entire device was determined to be 3 75 lbs Because the force required to move the device was more than twice the force required to move the slider there 1s low risk of the device tipping over or moving when the force 1s applied The force required to move the sliding board is also much lower than the force required to bend or deflect the sliding board according to the FEA results in the previous section In addition the force of 1 75 lbs 1s approximately equal to three medium oranges which should prove acceptable for the employees at Tri State t
53. pes of bolts overall There is one type of bolt for the plastic parts and one type for the sheet metal parts While assembling the device we found it very difficult to get a hold of the nuts for the board assembly The support tab in the back was blocking access so we had to grind out a piece of it In the final design this is now part of the initial sheet metal cutout This 15 shown Figure 8 1 1 37 Tab cutout to access nuts Figure 8 1 1 Assembly access improvement While trying it out ourselves we noticed that it was easy to drop parts onto the floor if the hole was missed In the final design we included a catch tray on the front of the device that will catch parts before they fall onto the floor This is shown in figure 8 1 2 Catch Tray Figure 8 1 2 Catch tray improvement We did not waste any material for the prototype and we did not make any changes to the material for final design Therefore there are no savings material for the final design 9 0 Final Design for Production 9 1 Design Description and Operation 38 Figure 9 1 1 Final Design Front Isometric View Figure 9 1 2 Final Design Rear Isometric View The finished product has the following features Table 9 1 1 Final Design Features ___ ______ Material Description 1 Has 50 one inch holes to place parts into during counting with four additional holes in each corner for bolts for se
54. pt D Figure 5 3 2 is a 50 hole rotating disk concept Both concepts are very broad but are different in how they operate The other major difference between the two would be the release mechanism that would be activated by the consumer to release the small parts into a bag A major cause of error in the counting process done by the consumers 15 the transferring of small parts from the jig to the bag The bagging process is an important focus to improve the quality control need required by Tri State The release mechanism for Concept C would be to pull or slide the bottom board to release the parts into a funnel or tube to the bag The board could be moved by hand or by lever We also believe a board would result in a smaller device because the holes could be placed fairly close together in a row and column pattern A Connect Four game concept was taken into consideration for this idea 29 The release mechanism for Concept D would be rotating the upper disk so all the parts fall below into a funnel It would be fairly difficult to fabricate a disk with 50 holes in it however 1 may function better than a board 6 0 Final Design Concept The Final Design Concept chosen for further development is a combination of Concepts B and C There will be a middle slider board sandwiched between to stationary boards When this middle slider board is pulled laterally holes in the top and middle boards will align and the small parts hardware will fal
55. referably but a laser cutter into the following shape see Figure 9 2 2 Figure 9 2 2 Metal Stand Cutout including Perforations Assembling this device is also very simple Once the metal stand Figure 9 2 2 is bent into shape and the plastic boards are cut into shape they only require nuts and bolts to be secured This hardware also doesn t require any special torque loads when tightening Therefore the only tools required 15 a flat head screw driver and an appropriately sized wrench The plastic boards will receive four bolts the funnel will receive four bolts and the shield located at the base of the plastic parts used to catch any parts accidently dropped during the loading process will receive four bolts as well All the holes to receive bolts are predrilled Adhesive is also used is some locations such as the stoppers on either side of the slider board and the foam pads on the handles if pads are desired The stoppers are extra pieces of UHMW cut to fit on the slider 42 handle to restrict undesired motion Please refer to the User s Manual for additional information on safety See Appendix D The approximate cost of such a production plan would be Table 9 2 1 Production Cost Rundown Cost Total 5170 Operations Basic Operations 100 Overhead 50 Equipment 560 Factors 12 hour Special Operations Added 25 Tolerance Factor S60 520 hour Ultra High Molecular Weight Polyethylene 5120 Ul
56. se devices Although not a good strategy for other facilities Tri State Industries is not run totally by volume output As long as the orders are filled in time which they have sufficient quantities they succeed Furthermore the plugs are simply a delighter in the overall product concept they are an optional feature depending on the needs of the individual customer Given these product outcomes the device 15 ready to be released to the customer Tri State Industries CNC programs have been written for manufacturing the plastic boards and CNC programs can be attained through the initial metal fabricator Detailed part drawings are already made see Appendix E Before the device is fully production ready more detailed production plans with actual fabricators would need to be set Also 1 enough of such devices are requested based on market review the per unit production cost may decrease to a more widely accepted value allowing the product to be more production ready 48 5 Candy Nut and Tablet Counting and Packing Machine ECplaza lt http www ecplaza net tradeleads seller 4911144 candy nut and_tablet html none gt accessed November 4 2008 Erickson W amp Lee C 2008 2007 Disability Status Report United States Ithaca NY Cornell University Rehabilitation Research and Training Center on Disability Demographics and Statistics Fairfax Richard E Standard Interpretations Occupational Sa
57. t mid side nodes consisted of the board being allowed to slide The cut surface was constrained in the Z and X directions while the back surface was constrained in the Z and Y directions A load was placed in the negative Z direction on the handle to simulate the user pushing downward on it The load was varied between approximately 25 and 50 for each case After running all several analyses it was determined that the part will likely fail with a load of approximately 50 Ib Just before this load the maximum deflection is approximately 0 84 in sample of the stress results was seen Figure 7 2 3 The complete results of the analyses can be seen in Table 1 below Scenario 1 1s without mid side nodes and the cut 15 fully fixed Scenario 2 1s without mid side nodes and the cut is not fully fixed and Scenario 3 is with mid side nodes and the cut is not fully fixed The convergence of the analyses was tested by calculating the percent differences of the maximum Von Mises stress and the maximum displacement for the 0 3 in 0 2 in and 0 1 in meshes of Scenario The results of these calculations can be seen in Table 2 below Although the maximum Von Mises stress was determined to reach the tensile strength with a load of approximately 50 Ib the load is unlikely to reach this amount in normal operation This 15 due to the fact that the user will be seated while reaching upward to slide the middle board However it is possible to
58. the sliding board was found to have a maximum stress of approximately 1 700 psi at the location indicated in Figure 7 2 1 below This would give a factor of safety of 1 82 for a 25 15 load von Mises Ibfifin 2 Ly Load Case 1 of 1 X Maximum Value 1583 08 Ibf in 2 7 ang A E Minimum 1 2603 052 Figure 7 2 3 Von Mises Stress 0 1 in mesh 25 force cut fully fixed 7 2 1 however the stresses for this load indicate that the sliding board would fail at this load Upon physical testing it was determined that this was fact incorrect Upon be subjected to a ad much greater than 50 165 the material simply bent there was no fracture of the materia The testers were able fo bend hinear picee of the materiaHnto a circular Shape without failure It is believed that the reason for the discrepancy between physical wales and the finite element analysis was a result approximation of the material properties in ALGOR Because UHMW 34 Polyethylene was not in the material library of ALGOR its Modulus of Elasticity Poisson s Ratio and Tensile Strength were added in order to simulate the material Further details of the analysis are shown Appendix 7 3 Mock ups Experiments Testing In addition to the simulations run in ALGOR several physical tests were performed to validate the prototype The first of these tests involved determining if the device would bend deflect tip
59. tically count cylindrical parts The system uses a specially designed gear to collect one rod at a time and deposit it into a trough The rotational speed of the gear can be varied to control the speed of discharge The rotation activates a clicker that mechanically keeps track of the number of parts NA i Sal 2 6 1G Ao XX 6 ALAS 7772 N 22 O 77 222222 ENE 21150022 NA 25 29 WIA SY gt 63 gt Sorting Machine U S Patent 2 156 822 See Figures 4 2 3 and 4 2 4 details a sorting machine that first gauges the acceptability of bolts The machine then accepts correctly dimensioned parts or discards incorrect parts The important concept pulled from this patent was the method of transporting bolts down the line 15 Figure 4 2 4 Side View of Bolt Sorting and Gauging Machine Sorting Machine U S Patent 6 787 724 See Figures 4 2 5 4 2 6 4 2 7 and 4 2 8 details a method for aligning transporting and rejecting dimensionally inaccurate parts This patent details several concepts could be used to satisfy our customer needs including the ability to automatically orient parts transport parts through a system and for depositing parts 16 YO GA SS 126 2 14 22 Figure 4 2 5 Method to Align Fasteners for further processing 22 ss Figure 4 2 7 Continued Fastener Transportation usi
60. to adjust the clearances of the plates and magnetic force to get a comfortable sliding force We should set a quantitative goal based on the strength of the users the friction forces and the tipping moment and try to meet that goal to make 1 easy to use and prevent the need of a clamp 6 We will repeat each data recording five times and take the average to get an accurate value C 6 Results The results from our experiment can be seen below in Table C 1 The data for the slider pulled without magnets is recorded as LNM right no magnets and left no magnets respectively For the slider pulled with the magnets installed the abbreviations RM and LM were used Graphs made from the data all resemble the graphs below Figure C 3 below shows the results of sliding the entire device alone on the table The maximum force needed came to be about 3 75 pounds The maximum force to pull the slider without the magnets was approximately 0 75 pounds The maximum pull required to move the slider and overcome the magnets was approximately 1 75 pounds C 7 Uncertainty Analysis Due to the simplicity of the prototype and experimental procedure error was kept to a minimum However some error was present in the data acquisition device used to measure the required input force The Vernier Force Probe has two settings where 1t can measure a maximum force of ION 503 When measuring the force required to pull the middle board across the
61. tra High Molecular Weight Polyethylene Static Dissipative TOTAL 290 For the operations section the labor cost was calculated as 1 Basic Operations 2 hours for stand production and overall assembly i 2 hours xi x 1 1 0 5 60 hour 2 Special Operations CNC Milling 30 min for top board b 30 min for middle board 5 for bottom board 65 min x x 1 1 0 5 0 25 60 min hour If the customer would also choose to have plastic plugs made to restrict the number of holes available for counting the cost estimate is as follows 1 Materials a 5 ft of UHMW PE 52 37 2 Special Operations a 60 min for 35 plugs 1 hour 20 60min hour i 60 min x 1 1 0 5 0 25 55 43 3 Total Cost a 35 plugs would cost an additional 12 55 67 b Final cost of product with plugs 15 357 9 2 1 Design Drawings Parts List and Bill of Materials The design drawings further detail the product They show manufacturing tolerances exploded views of more detailed sections as well as parts lists These drawings are given in Appendix E In order to professionally and efficiently draft all parts of the SPCaBD a drawing border was developed specifically for Team HandiCats The drawing border contains important information pertaining to each part s tolerances and features Figure 9 2 3 shows the information block within the drawing border Proprietary Information Re
62. ught we should include as well After meeting we came up with an initial list of target specifications that highlighted all the needs but did not quantify everything We went back to Tri State a second time to observe the consumers at work to try to get a more detailed understanding of their needs We asked them questions and watched them work We did time trails to see how long it would take different consumers with different abilities to do different tasks The supervisor and the production manager for this process were also consulted to get quantitative target specifications After our second visit we met as a team to finalize and quantify all the design criteria and target specifications Our design criteria and specifications are as follows 10 Table 3 3 1 Target Specifications Based on Customer Feedback Customer Specification gt 4 stations per 3 x 8 table lt 1 error Ease of Operation 2 Open job to new workers previously unable to do work Metal or Plastic Adaptability lt 1 bolt size lt 50 parts able to be counted production Rate Target Spec 15 6 parts min FF Criteria 50 parts min Weight labs Safet No sharp corners or edges pinch points quick movements or unintended y within any moving parts Ergonomics Workers must be Workers must be comfortable when using Based on employee feedback when using Workers must be comfortable when using Based on employee feedback
63. ve been no documented experiments found in our research where both 54 of these factors have been taken into account Additionally little research has been done into the effects of using a steel stand such as with this system on a laminated wood surface For these reasons the experiment at hand is quite important The workers also known as Consumers by Tri State Industries have limited mobility which suggests that the force required to slide the middle board between the top and bottom boards should be minimized without allowing the stand to slip on the table Both the safety and well being of the consumers are of the utmost importance in this project The system should be designed such that the force required by the consumer is minimized and that the system will not slide on the table upon which it 15 set up The results of this experiment will impact whether the system will be attached to the table and how so If the system is found to slide only slightly a solution such as rubber feet could be employed However if the system is found to slide more than slightly clamps could be purchased in order to attach the stand to the table C 5 Experimental Procedure A force Gauge will be needed for this experiment The force gauge will be attached to the middle handle of the sliding middle plate Refer to figure 2 1 for the apparatus diagram Data acquisition from the computer can be used to record the force vs time 1 The SPCaBD will be plac
64. vision Block Tolerance Specifications PROPRIETARY INFORMATION UNLESS OTHERWISE SPECIFIED DATA ENCLOSED HEREIN IS NOT TO BE DISCLOSED TOLERANCES SURFACES 125 USED OR DUPLICATED FOR ANY PURPOSE EXCEPT SENIOR DESIGN TEAM 8 AS AUTHORIZED IN WRITING BY OHIO UNIVERSITY FRACTONAL 1 64 ATHENS OH USA RUSS COLLEGE OF ENGINEERING amp TECHNOLOGY XX 100 SENIOR DESIGN TEAM 8 BREAK ALL SHARP EDGES DRAWN BY DATE MATERIAL po AK APA sam vo DWG 1 Figure 9 2 3 Drawing Border Information Block The information block of the drawing border states that unless specified in the drawing specific tolerances are to be followed based on the number of decimal places present in each dimension Figure 9 2 4 is a close up of the Tolerance Specification block 44 UNLESS OTHERWISE SPECIFIED ALL FINISHED DIM TOLERANCES SURFACES 125 FRACTONAL 100 BREAK ALL SHARP 010 EDGES N 5 SQUARENESS ANGULARITY RUNOUT TRUE POSITION PARALLELISM CONCENTRICITY Figure 9 2 4 Tolerance Specification Block 10 0 Conclusions The goals objectives of this project as stated in Section 1 0 4 were concluded as follows 1 Assist people with disabil
65. well as phone calls the HandiCats were able to create an initial list of customer needs These needs shown below in Table 2 0 1 are driven by the voice of the supervisors and consumers at Tri State as well as by team discussions Table 2 0 1 Initial Customer Needs Determined by Both Customer and Team Size Quality Control Ease of Use Low Maintenance Adaptable Productivity Moveable Safe Cost This initial set of customer needs led to the following needs statement There 15 a need for the advancement of jigs to assist in the counting and bagging of nuts bolts and washers for employees with physical and or mental disabilities After discussing the initial customer needs list with the customer it was determined that all of the included needs should remain on the list In addition the supervisor and consumers thought that aesthetics should be placed on the list 2 1 Weighting of Customer Needs Although all the customer needs are important their levels of importance vary greatly For this reason the team assigned an initial weight factor to each of the ten needs The needs were first ranked order from 1 to 10 with 1 being the most important and 10 being the least important Weightings were then assigned based on the rankings Table 2 1 1 shows the weighting of the needs based on team evaluations Table 2 1 1 Team s Weight Factors of Customer Needs Weight Factor 0 18 0 18 0 15 0 15 0 10 The survey s
66. works perfectly 8 0 Design Refinement for Production Design Refinements Cut out part of rear tab to access board assembly nuts Catch tray to catch parts that were dropped Shortening the length of the bolts so parts would not get caught in the funnel Changing the dimension and tolerance for the slider board height to allow it to slide with enough clearance without slotting any holes Changed manufacturing processes to reduce time Remove rear support part We noted the issues we had while assembling the device From the assembly process we found a lot of issues that needed changed to ease the manufacturing We also tried out the device ourselves One of the ways we refined our device was by sending the prototype to the customer 36 to get feedback We had the customer write down any problems and recommendations they had for it Overall they were satisfied with the design with some minor changes We did a cost analysis of the prototype to look at possibly reducing the cost for the final design 8 1 Final Design Development and Validation All the validation is described in section 7 for the prototype validation We did not do any additional validation for the final design changes The changes were small and did not require any FEA or physical tests The impact of our DFMA and design changes made it easier and quicker to manufacture and assemble These changes also made it function better We made changes to the manufacturin
67. would never be separated from the top Figure 4 3 5 Sliding Plate Assembly 21 4 3 4 Concept 0 Rotating Disk This concept 15 similar to concept but instead uses rotation Two disks with 50 holes each lie on top of each other but the holes are misaligned The operator fills each hole with one part and turns the top plate when each hole is filled The bottom plate remains stationary so when the top holes align with the bottom holes the parts fall through into a bagging device Figures 4 3 6 and 4 3 7 show this idea Figure 4 3 6 Isometric Front 22 Figure 4 3 7 4 3 5 Concept Roulette Wheel Our final concept is similar to concept D in that it rotates however the part layout 1s much different This idea has separate places for the bolts and the nuts and washers The bolts are laid down in the inner two rings with the place for the nuts and washers the outer ring Unlike other concepts an entire order can be done in one step Once the desired number of parts has been placed the operator activates a trap door that opens under the parts The operator then turns the device 360 to allow all the parts to fall through the trap door in a bagging device This is illustrated in Figures 4 3 8 and 4 3 9 23 Figure 4 3 8 Isometric Front Figure 4 3 9 Top 4 3 6 Concept F Grocery Scale This concept is based off of a grocery scale in a produce department A completed order is weig
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