P10811: The Ultimate Tailgate P10811: The Ultimate Tailgate Detailed Design Review February 12 th, 2010 Jonathan Brooks – Project Manager Spencer Herendeen - EE Matthew Piatkowski - ME 1Ultimate Tailgate Prototype

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Agenda  Project Overview: Scope and Background  Project Objectives  Updated Customer Needs  Meeting Outcome  Project Progress  Renewed Risk Assessment  Mechanical System ◦ Design ◦ Feasibility Analysis  Electrical System ◦ Design ◦ Feasibility Analysis  Budget and Bill of Materials  Preliminary Test Plan  Next Steps 3Ultimate Tailgate Prototype

 The main purpose of this design project is to provide a fully functioning prototype to show proof of concept and satisfaction of customer needs.  Tailgate hardware and detailed documentation is to be provided for Mark McVea and MTM Tools, LLC by end of MSD II May 21, 2010  Provide basic functionality with the understanding that future iterations will have additional features 4Ultimate Tailgate Prototype

Project Objectives: Prototype  Design is to provide: ◦ Structure of steel tubing with a sheet metal or fiberglass skin providing a flat work surface ◦ A main Black & Decker Workmate clamp and an auxiliary quick release clamp ◦ Pull out storage drawers ◦ Electrical power capable of converting power from a vehicle battery to standard 120 V AC /15 A AC outlet power via an inverter ◦ A set of relays to turn the power on and off during critical conditions ◦ A LED indication bank to communicate with the user ◦ A standard kill switch for manual electrical shutdowns 5Ultimate Tailgate Prototype

 Finished preliminary detailed design  Finished preliminary design analysis  Awaiting approval for finalizing design  The following slide shows the breakdown of tasks completed since last meeting 6Ultimate Tailgate Prototype

Project Progress: Prototype 7Ultimate Tailgate Prototype

 By the end of this meeting we hope to achieve the following: ◦ Approval on system designs ◦ Constructive input ◦ Suggestions on design improvement ◦ B.O.M. approval 8Ultimate Tailgate Prototype

9 IDRisk ItemEffectCause Likelih ood Severi ty Impor tance Action to Minimize Risk Owner 13 Excessive Losses in wire Battery drained prematurely Wire too long and/or thin 326 Choose proper wire diameter SH Wire unable to carry sufficient power 14 Electronics damaged by weather Electrical system inoperable Poor choice of system location 236 Ensure proper weatherproofing MP Electrical system lifespan reduced Insufficient system protection 17 Tailgate too heavy to lift manually Assistance required for lifting Components and features too heavy 339 Design assisted lift mechanism MP, JP Drawer capacity too high Reduce drawer capacity 18 Raw materials ruined during fabrication Increased material cost Poor craftsmanship 236 Ensure proper fabrication techniques are used JB Increased fabrication time Order extra material

TailgateElectricalInverter Location Type Charge assess ment Current mode switch Over current/ voltage protection Mechanical Material Storage Clamp Lock Latch Outlet location

Ultimate Tailgate Prototype11 Workmate Electrical Components Drawers Work Surface Clamp Mount

 Relocated Workmate ◦ Moved to one end of the tailgate and rotated 90 ° ◦ Allow for parts to overhang off tailgate  Relocated drawers ◦ Moved to one side and side by side ◦ Allow room for workmate  Changed drawer shape ◦ Changed from pie shaped to rectangular ◦ Slide out instead of pivot out ◦ Ease of use Ultimate Tailgate Prototype12

 Changed auxiliary clamp mount ◦ Removable modified clamp with dedicated mount ◦ Ease of use, modular clamp location  Changed latching mechanism ◦ Single handle with cable actuated side latches ◦ Ease of use  Changed locking access door ◦ Recessed into tube structure, not weatherproof ◦ Ease of production ◦ Drawers and outlets are independently weatherproof Ultimate Tailgate Prototype13

 Changed tailgate thickness ◦ From 3.5 in stock to 4.5 in ◦ Account for taller drawer Ultimate Tailgate Prototype14

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Electrical Schematic Design: Prototype  The next slides will show both the electrical system breakdown and all necessary circuit designs that need to be implemented to meet customer needs. In addition, there is a flow diagram of the system operation  For this meeting: Dr. Hoople could not be here today, so all electrical system collaboration and criticism will occur at a different time 20Ultimate Tailgate Prototype

Electrical System Design Block Diagram Hierarchy: Prototype 21Ultimate Tailgate Prototype LEGEND Outputs Critical Shutoff Circuits

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 The following slides will demonstrate an FEA analysis of the drawer ◦ The study was conducted with a 50 lb load applied to the inside surface of the drawer ◦ The bolt holes to the sliders were constrained ◦ The results shown are displacement, stress and factor of safety 24Ultimate Tailgate Prototype

25Ultimate Tailgate Prototype Max Displacement: in

26Ultimate Tailgate Prototype Max Stress: psi Yield Stress: 47,900 psi

27Ultimate Tailgate Prototype Min FOS: 3.2

 The following slides will demonstrate an FEA analysis of the tube structure ◦ The study was conducted with a 500 lb load applied to the top surface of the tube structure ◦ The two front and two rear joints were constrained ◦ The program used only allows joints to be constrained in beam structures, looking into different methods ◦ The results shown are displacement, stress and factor of safety 28Ultimate Tailgate Prototype

29Ultimate Tailgate Prototype Max Displacement: in Elastic

30Ultimate Tailgate Prototype Max Stress without stress concentration: ~40,000 psi Yield Stress: 47,900 psi

31Ultimate Tailgate Prototype Max Stress without stress concentration: ~40,000 psi Yield Stress: 47,900 psi

32Ultimate Tailgate Prototype Max FOS without stress concentration: ~1.4

33Ultimate Tailgate Prototype Max FOS without stress concentration: ~1.4

 The following slides will show the force required to lift the tailgate at various angles ◦ One concern is that the tailgate will become too heavy to lift ◦ The force needed to lift the tailgate with fully loaded drawers (50 lbs each) is 91 lbs ◦ Counter methods include  Spring assisted supports  Actuation  Garage door style torsion spring 34Ultimate Tailgate Prototype

 The following graph shows the force required to lift the tailgate as it swings up from opening to closing  Angle of zero represents tailgate in the open position, angle of 90 represents closed  Forces shown are normal to tailgate work surface  Force shown applied at top edge of tailgate Ultimate Tailgate Prototype35

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Electrical Design Prototype: Feasibility Study  The next slides show calculations relating to the time that the electrical system should run. From these results, it can be summarized that: 37Ultimate Tailgate Prototype Time at which battery is drainedTime at which truck needs to be started Truck Off21.6 minutes7.2 minutes Truck On25.44 minutes11.4 minutes This means that, under these numbers this is how long under max load the system can last For example, if the truck is on it is safe to run a circular saw continuously for 11.4 minutes

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Bill of Materials 40 Ultimate Tailgate Prototype Mechanical Total$ Electrical Total$ Shipping Estimate$ Total $1, Already Spent$ Left to Spend$1,355.23

Bill of Materials 41 Ultimate Tailgate Prototype PartSourceP/NPrice Per UnitQTYPrice Mechanical 3/8-16 x 1.25 Flat head socket cap screw (10 Pack)McMaster92210A626$6.862$ /8-16 Half height nuts (100 Pack)McMaster94846A031$7.871 Black and Decker WorkmateLowes176390$ Irwin Quick Bar ClampLowes $ TailgateJunkyard---$ x 1.25 x 0.065Metal SupermarketsHTSQ ft$72.93 Sheet MetalMetal SupermarketsHSH ft x 4 ft$48.83 LumberLowes--- $20.00 Hinge for Locking Door and Drawer LidMcMaster 11785A23 $ Draw Latch for Drawer LidMcMaster1889A34$4.662$9.32 Push Open Drawer CatchMcMaster 10825A26 $5.244$20.96 Drawer SlideLowes50184$13.482$26.96 Bar Clamp Mounting RecessMetal SupermarketsHC ft$11.34 Bar Clamp Pin RodMetal SupermarketsCR1018/ ft$5.50 Quarter Turn FastenersMcMaster94170A535$ Drawer Sealing GasketsMcMaster1120A341$1.3920$27.80 FiberglassUS compositesFG-03438$1.9510$19.50 ResinUS compositesSM $ MoldLowes--- $50.00 Welding SuppliesMahaney--- $30.00 Surface Finishing Supplies (paint etc)Autozone--- $50.00

Bill of Materials 42 Ultimate Tailgate Prototype PartSourceP/N Price Per Unit QTYPrice Electrical Capacitors Mouser --- $5.00 Resistors Mouser --- $ timer Mouser ---$2.001 Relays Digikey ---$6.008$48.00 Circuit Protection FusesMouser 1812L260-C $0.5914$8.26 Circuit Protection Breaker Mouser 655-W51- A121B1-10 $2.794$11.16 Cobra CPI 2575 Inverter powersystemsdirect. com $ /0 Wire Discount Wire Supplier $4.0045$ Test BatteryAutozone---$ Perforated Circuit BoardMouser $10.002$20.00

43Ultimate Tailgate Prototype Test IDSystemSub-SystemDetialsOwner 1ElectricalInverter Test inverter output under load SH 2ElectricalRelay Circuits Test relays to ensure draw is not exceeded SH 3ElectricalLED bank Test user feedback system operation SH 4ElectricalWiring Test wiring withstands power output SH 5ElectricalKill Switch Test kill switch under critical conditions SH 6MechanicalStructure Test tailgate structure load capacity MP, JB 7MechanicalMain Clamp Test main clamp functionality, clamping force MP, JB 8MechanicalAuxiliary Clamp Test auxiliary clamping force capacity MP, JB 9MechanicalDrawers Test drawer stucture load capacity and sliding function MP, JB 10MechanicalHinge/Cables Test tailgate mounting load capacity MP, JB 11System Integration, and Final Test Test system component interaction and overall function MSD Team

 Senior Design II ◦ Material Ordering ◦ Design Implementation (Fabrication) ◦ System Testing ◦ Integrated Testing ◦ Write up operators manual ◦ Prepare print package 44Ultimate Tailgate Prototype

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46Ultimate Tailgate Prototype 9 Too much draw for alternator Battery Dead, can't start truck Needs exceeds capacity224 Assess max draw SH Bigger Alternator 10Electronics overheat Electronics burn/stop working Over current 133Offer bigger heat sinkSH Over voltage 11Over budget Project can't be completed Too many features 133Update budget regularlyJB Too much bought not designed 12 Resettable fuses do not function as intended Resettable fuses blowCurrent not split evenly 212 Provide enough fuses to split current SH Power delivery incorrect Parts do not provide enough protection Have breaker as back up 13Excessive Losses in wire Battery drained prematurely Wire too long and/or thin 326 Choose proper wire diameter SH Wire unable to carry sufficient power 14 Electronics damaged by weather Electrical system inoperable Poor choice of system location 236 Ensure proper weatherproofing MP Electrical system lifespan reduced Insufficient system protection 15 Overdraw on relay circuits Degeneration of relay performance Too much draw from battery or inverter 122 Choose high tolerance relay SH 16Tube structure too weak Tailgate deforms under load Tubes too small 224 Perform FEA analysis JB Poor weld quality Use proper welding technique 17 Tailgate too heavy to lift manually Assistance required for lifting Components and features too heavy 339 Design assisted lift mechanism MP, JP Drawer capacity too highReduce drawer capacity 18 Raw materials ruined during fabrication Increased material cost Poor craftsmanship236 Ensure proper fabrication techniques are used JB Increased fabrication timeOrder extra material