1. Eric Hettler - ME William Gallagher - ISE Christopher Mieney - ME Gregory Ryan - ME Joseph Cole - EE FAB AMERICA

2. Design Review Agenda Project Overview Customer Needs Customer Specifications Concept Development and Proposed Design-Material Delivery Concept Development and Proposed Design-Color Delivery Concept Development and Proposed Design-Curing System Concept Development and Proposed Design-Motion Control Project Plan Risk Assessment

3. Project Overview Fab@Home open-source architecture Print photo-curable resin Color printing used as a vehicle to demonstrate multi-material print capability http://fabathome.org

4. Customer Needs Customer Need #ImportanceDescriptionComments/Status Safety CN1HighContains the UV radiation CN2LowMoving Parts will not hurt the userScrapes, pinching, sharp edges Multicolor/Material CN3HighCapable of printing multi color CN4HighCapable of printing photopolymerCured by UV light Repeatability CN5MedLayer to layer CN6MedPart to part Accuracy CN7MedPosition VariabilityPrint head can retrieve location CN8MedColor Variability Fab@home mindset CN9HighLow Cost CN10LowGraphical User Interface CN11MedEasy to read User Manual Speed CN12MedPrints relatively quickly CN13HighDoes not take a copious amount of time to cure CN14LowCan be set up quickly and easily Aesthetics CN15MedMachine looks presentable CN16MedOperation is smooth and observable

5. Engineering Specifications Eng. Spec # ImportanceSourceSpecsDescription Unit of Measure Marginal ValueDesired Value ES1HighCN1Contain the UV radiation% Absorbed at 355 nm%8090 ES2LowCN2 No physical damage to users Opening sizecm^2< 1<.5 ES3HighCN3Can Print MulticolorQuantity of reservoirs#33 ES4HighCN4Can Print PhotopolymerViscosity of epoxycP165 ES5MedCN5Layer to LayerVariance of layer thickness%+/- 5+/- 2 ES6MedCN6Part to PartVariance of part dimensions%+/- 5+/- 2 ES7MedCN7Positional VariabilityToleranceinch0.0010.0005 ES8MedCN8Color VariabilityPrint Multiple Colors# of colors> 1> 256 ES9HighCN9Low CostStay within Budget$< 3,000< 2,500 ES10LowCN10Graphical User InterfaceSurvey of operators% Approval> 70> 80 ES11MedCN11User ManualSurvey of operators% Approval> 70> 80 ES12MedCN12Print SpeedRate of flow from print headmm^3/sec0.10.2 ES13HighCN13Curing Time Time to cure a given amount of epoxy sec/cm^2< 3< 1 ES14LowCN14Setup Time Time to prepare machine for operation mins< 30< 15 ES15MedCN15MachineSurvey of random people% Approval> 70> 80 ES16MedCN16OperationSurvey of random people% Approval> 70> 80

6. Systems Overview

7. WaterClear® Ultra 10122 Stereolithography Resin For Solid State (355nm) laser systems Looks like acrylic Feels like ABS

8. Material Delivery Concepts ABC Ball Point ApproachMicro-Valve Disposable Syringe (control) Selection Criteria DescriptionWeightRatingWeightRatingWeightRatingWeight CostLow cost10%30.303 40.40 Speed Speed at which the print head dispenses epoxy 15%20.3040.604 PrecisionDroplet size consistency20%20.4051.0020.40 ServiceabilityEase of maintenance15%10.1530.4550.75 Feasibility How possible it is to implement the system 25%20.5041.0051.25 Controllability Ability to control the motor with the given software 15%30.4550.7540.60 Total Score 2.10 4.10 4.00 Rank 3 1 2 Continue? No Yes No Material Delivery Concept Selection

9. Material Delivery Proposed Design: material delivery nozzles Tube ID:.033”-.002”Proposed Design: Micro Valves Photos From The Lee Company

10. Material Delivery Nozzle size can range from 30ga. to 14ga. (.006”-.069” inner dia.) 30 gauge 0.006" (0.229mm) Inside diameter http://www.shop.cmlsupply.com/product.sc?productId=236&categoryId=-1 http://www.bhphotovideo.com/c/product/176022- REG/Photographers_Formulary_09_0350_Micro_Mixer_Measuring_Syringe_12ml.html

11. Color Delivery Concept Selection

12. Color Delivery Concepts Pre-Colored Epoxy Reservoirs Deposition Mixing Process Deposition Carrier Stream Dye/Pigment Reservoirs Mixing Process Epoxy Reservoir Carrier Stream Dye/Pigment Reservoirs Mixing Process Proposed Design: Pre-Colored Resin Design Alternatives: Color Injection Deposition Mixing Process

13. Motion Control Concepts AB Servo MotorStepper Motor (Control) Selection CriteriaDescriptionWeightRatingWeightRatingWeight CostLow Cost20%30.6040.80 Speed How fast the print carriage moves 10%30.303 Accuracy Ability to move to a given position 30%41.2030.90 SizePhysical volume10%30.3040.40 Ease of Control Ability to control the motor with the given software 15%20.3050.75 Range of MotionAchievable positions15%30.453 Total Score 3.15 3.60 Rank 2 1 Continue? No Yes Motion Control Concept Selection

14. Motion Control Assessment E35 H4B-05-012 Used for the x and y axis..000625inches (.0158mm) per step

15. Motion Control Stepper Motor Servo Motor http://jrkerr.com/snapmotors/

16. Curing Concepts ABCD Overhead Light Mini-Halogen (offset method) LED (offset method) Laser (ring method) Selection CriteriaDescriptionWeight RatingWeightRatingWeightRatingWeightRatingWeight CostLow cost10%50.5040.4010.101 Speed Speed at which the light cures the epoxy 20%20.4030.603 40.80 Feasibility How possible it is to implement the system 25%51.2541.004 20.50 Thoroughness Its ability to cure completely 25%30.7541.0020.5051.25 Controllability Ability to control the motor with the given software 20%51.0030.603 3 Total Score 3.90 3.60 2.80 3.25 Rank 1 2 3 4 Continue? Yes No Curing System Concept Selection

17. Potential Light Sources – LED’s Led Spot Cure Linear LED Array -Current LED control boards frequency output is too high (365nm.) Resin cures at 355nm. -Too expensive, $1650 -Fast cure times, 0.5 seconds -Cost is approx. $400

18. Overhead Lights Florescent UV Advantages Inexpensive, ~ $30 Ease of implementation Florescent UV Drawbacks Low Power, ~ 40 W Greater distance to part yields longer cure times UV Flood Lamp Advantages High power, up to 400 W Cure Times 5-30 sec UV Flood Lamp Disadvantages Poor irradiance at 355nm

19. Potential Light Sources - Laser -Current platform is too large for existing architecture.

20. Potential Light Sources – Mini Halogen Benefits -Small Size, bulb diameters ~ 5mm -Inexpensive, $15-75 Drawbacks -High operating temperature, > 250 C -Output at required wavelength somewhat low -irradiance @ 355nm = 3.05E-3 (W/cm^2) Cure Time Estimate

21. Curing System – Light Delivery Concepts

22. Project Plan

23. Risks