P14311: PCB Isolation Routing System

P14311: PCB Isolation Routing SystemSystems Design ReviewAgendaItemTime AllottedIntroduction 2 minutesReview Problem Definition 5 minutesBenchmarking 5 minutesFunctional Decomposition 5 minutesConcept Development10 minutesEngineering Analysis10 minutesTest Plans 3 minutesRisk Analysis 5 minutesSchedule Update 3 minutesQuestions?12 minutesSarahTeam IntroductionsNameMajorRoleMatthew ClarkMELead Mechanical EngineerMarley Collier SearsMEME Interface ManagerSarah DumanIEProject ManagerRichard KalbEELead Electrical EngineerJoseph PostEEEmbedded ControlsZoe RabinowitzMEDocumentation ManagerKevin RichardEEEE Interface ManagerOur Senior Design TeamJoeProblem StatementRIT students need rapid prototyping for creation of unique circuit boardsRequires multiple revisions to perfect each circuit boardCurrently each iteration must be created off campusLong lead timesExpensiveLimits circuit refinementStudents not involved in process

Marley; At RIT, students with needs for printed circuit board technologies are often faced with a series of challenges in creating unique boards. The typical fabrication process (which includes chemical etching) can be time consuming when multiple iterations of a prototype board must be created. Sending designs to be fabricated off campus can also be very costly. To reduce lead times and cost, an isolation routing system (milling system) could be developed to be used on RITs campus.Problem Statement (Continued)Isolation Routing SystemRapid prototypingInexpensiveIn-house fabricationStudents control production processProposed SystemCreate boards to accommodate through hole componentsEx. Improved Radiation Meter (Elektor PN 110538-71)Debris management system

MarleyBenchmarking- Scott Systems Isolation RouterAble to produce double-sided BoardSmallest bits used - .016Minimum width between traces - 5mm Stepper control for Z-axisStepper control for X-Y movementAlignment pins and double sided tape used to secure boardSacrificial plastic layerUses an air gun to blow dust out during the drillingPVC with shop-vac sucks up debris Data Flow Eagle design file G-code Flashcut CNC Motors

ZoeCreate table of system- hardware, software- high levelAdd benchmarking slide from previous slide show6Benchmarking- Scott Systems Isolation Router

Zoe7Pros, Cons, Potential ImprovementsPros:Can etch double-sided boardsEasy to switch bits 5mm minimum trace width Cons:System lacks real time feedback sensorsX,Y, and Z, axis alignment is done manually.ImprovementsImprove debris managementReplace or repair Z-axis motorEnclose system

Benchmarking- RIT Robotics LabMilling set-up is not used regularly because its a painZeroing the plane is highly mechanicalSmallest tolerance is 10 milFloor of the mill is warpedDifficult to change drill bitsInterface software include expensive IsoproManual debris managementUtilizes two alignment pinsBoard is secured down with tape

Zoe9Pros, Cons, Potential ImprovementsPros:Relatively InexpensiveCons:Difficult to swap bitsPoor board alignment processZ-axis solenoid ImprovementsDebris management systemZ-axis zeroing

Customer Requirements

MattMost Critical Customer Requirements

Matt12Engineering Requirements

MattMost Critical Engineering Requirements

Matt

14Functional Decomposition

Kevin15

Kevin

16

Kevin17

RJ18

RJ19Process Flow ChartTurn on Device / ComputerOpen Design FileAlign / Secure Bare Board on BaseRun ProgramProgram Prompts For Drill Bit ChangeProgram Pauses / Swap Drill BitProgram Prompts for Mill Bit ChangeProgram Pauses / Swap Mill BitProgram Alerts User it has FinishedFlip BoardRemove Completed Etched BoardIs There Another Side to Etch?YESYESYESNoNoNoP14311 Morphological Analysis

RJ21P14311 Morphological Analysis

RJ22Pugh Analysis

Joe23Pugh Analysis

Pugh Analysis

Concept #1

X-Y axis Control of Spindle AssemblySpindle Assembly Vacuum Nest with Alignment PinsUpper and Lower Acrylic GuardsZ axis Control of BaseCyclone SeparatorElectronic Waste Collection+ Combination nozzle/vacuum with cyclone separator effectively manages debris+ Straight forward design easy to understand+ Vacuum nest and alignment pins ensure accuracy and repeatabilityPressurized Air Nozzle- Minimal guards allow access to moving parts during operation- Difficult to relocate, much larger than Ryans and Robs systems- Large weight of gantry limits maximum accuracy- Redundant systems increase complexityMarley26Concept #2+ Collet for holding tooling+ Suction debris removal+ Alignment Template system

- DC motors with encoders for X,Y,Z- Horizontal Vice for mounting

MAtt27Concept #3Concept #4Concept #5Concept #6+ X- and Y-axis control using steppers and lead screws, which offers great resolution+ Fully enclosed unit provides a much safer operating environment+ Interlock would safely disconnect power in case of emergency/unit malfunction+ Unit is overall very easy to use (assuming board is aligned)- Incineration not a feasible method of debris management- Rack and pinion Z-axis movement control would cause unnecessary backlash- Board alignment not very easily performed with electromagnets

Joe31Concept #7Hybrid Design

Joe33Pugh Total ScoresScott SystemsRobotics LabConcept 1Concept 2 Concept 3Concept 4Concept 5Concept 6Concept 7Hybrid DesignTotal +0234443434Total S0332014225Total -0544653451Total Score0-3-10-2-100-23Total Rank21062862281Joe34Hybrid Solution- Selected Concept

Stepper Motor with Lead Screw for Y Axis ControlStepper Motor with Lead Screw for X Axis ControlStepper Motor with Lead Screw for Z Axis ControlVacuum Clamping w/ Replaceable Sacrificial LayerGuide RailsVacuum AttachmentPressurized Air NozzleSpindle Motor and Collet AssemblyVacuum Clamp Sourced From Main VacuumX and Z Axis Wire Management Debris Management Vacuum AssemblyMarley35

Emergency Kill SwitchDoor InterlockAcrylic Door AssemblyTo Spindle VFD and X, Y, and Z Axis Stepper Motor ControlTo Vacuum Assembly with HEPA FilterTo Pressurized Air SourceMetal CasingDoor HandleHybrid Solution- Selected ConceptMarley36System Block DiagramMotor XMotor ControllerComputerDesign fileG-codeMotor ZMotor YUSB, serial, Ethernet, etcGUIPower SourceMain Logic BoardUSB, serial,Ethernet, etcDebris Management SystemInterlockPower conditioningMotor Theta37KevinAdd Motor thetaA system that creates negative pressure to hold down work pieces during machiningWill allow for easy set up by userWork pieces will be held down after being cutCollect debris being cut from board.

Engineering Analysis Vacuum Table

Matt38Engineering Analysis Vacuum Table

MattMarley will create quick excel on pressure/shop vac39Engineering Analysis Spindle vs RouterCommercial Routers

High Speed (~25,000+ RPM) but with manual controlLarge run out, not published as they are typically hobbyist and woodworkingRun directly from 120 VAC line powerHeat problem, not designed to be run continuouslyLow average cost (Free - $200)Brand specific colletsLoud

Low to Medium Speeds (usually 400 to 24,000 RPM)Extremely low run out (typically less than 0.005mm/0.0002)Need an inverter (capable of producing 0-400Hz @240VAC)Air or Water cooled options availableHigher average cost ($100 - $700)Standardized collet sizes (ER11, ER20, R8, 3MT, etc.)QuietSpindle Motors

Engineering Analysis Spindle vs RouterHigher cost of spindle motor justified by advantagesInverter vs. speed control, ~ equal complexity (VFD)More professional look and results from spindleJustifies laser centering upgrade in the futureEngineering Analysis Spindle vs Router

Marley- Look in the Rob Scott notes for his run out to quantify run out differences between routers and spindles42Engineering Analysis- Direct Material Cost Estimate

SarahPareto on top costs43Future Engineering AnalysisWeight analysisCan the Z motor handle the weight of spindle?Vacuum Analysis-Can one shop vacuum both collect debris and secure board?Does the vacuum have enough suction to keep the board secure while milling the outline?

RJ45Potential Test PlansPCB Trace Accuracy AnalysisAttach pen to Gantry to draw board on paperTest movement of carriageCheck condition power

Kevin Add picturesP13408 has good test plans to benchmark 46Risk Analysis

Zoe will add plan b column47

Zoe48

Project Schedule Update

Sarah50Project Schedule UpdateSarah51Project Schedule UpdateSarah52Subsystems Schedule

Sarah53

Questions?