High Temperature Pellet Based 3D Printer Head. System-Level Design Review Alyssa, Kylan, Jimmy, Ray 10/02/2014

Transcription

1 High Temperature Pellet Based 3D Printer Head System-Level Design Review Alyssa, Kylan, Jimmy, Ray 10/02/2014

2 Questions to be resolved 1. Do you think our concept is feasible? 2. Do you feel the engineering requirements are complete? 3. Are we missing any risks? 4. How fine (+ or - 5%/2%) do you think we should be able to grind the pellets? (full size pellets to powder)

3 Current Product 3dprintingsystems.freshdesk.com 3dprintingsystems.freshdesk.com

4 Problem Statement Current state: 3D printer heads use plastic filament, which has variable diameter and is quite expensive If the diameter varies too much, the feed mechanism fails Operation at temperatures up to 280 C Desired state: 3D printer head that uses ordinary plastic injection molding pellets as its feedstock Operation at temperatures up to 380 C Constraints: Cost < $500, preferably $200 Must be compatible with a majority of hobby grade 3D printers

5 Additional Deliverables CAD models of final design(s). Schematics for electronics. Bill of Materials with sources of components, quantities and cost. Clearly illustrated manual that provides instructions on how to build printhead Test results demonstrating nozzle is capable of extruding ULTEM high temperature plastic Test results demonstrating extruder can run continuously for 10 hours without clogging or failure

6 Customers Primary Customer: Dr. Denis Cormier- Earl W. Brinkman Professor Secondary Customer: 3D printing community: Plans to be made open to the Maker community under the typical open source non-commercial use terms.

7 Market Trends FDM patent expired in 2009, causing an explosion in the DIY 3D printing market. Since then, the cost of those printers has been reduced by 90%. In January 2014, the patent for SLS expired. Nothing of considerable note has been produced yet that is competitive with the current FDM printer prices.

8 Leading Manufacturers Stratasys holds the number one spot with 24.4% of the market share Reprap holds 19.2%, while Ultimaker holds 13.3% Stratasys was company that originally patented FDM. Their market share is large, but is decreasing as new manufacturers appear

9 Printer Model Distribution Makerbot Replicator 2 leads the models, followed by Ultimaker 1. These are some of the older printers, being manufactured in 2012 and 2011, respectively. The Prusa i3 has a surprisingly large distribution, considering it was manufactured in September 2014

10 Customer Requirements Customer Rqmt. # Importance Description CR1 9 Uses unmodified plastic injection molding pellets as its feedstock material CR7 9 Cost should not exceed $500 CR8 9 Documentation in the form of an operation manual required CR2 7 Must be capable of operating up to 380 C CR3 7 Must be able to print continuously for 10 hours without failure CR5 7 Nozzle's overall size and mass must be close to most 3D print head assemblies CR6 7 Print head must work with standard hobby grade 3D printers CR9 7 Parts readily available for Hobbyists to re-create the printer head - few specialty made parts CR4 1 Interchangeable nozzles are required so that different diameter nozzles can be used and clogged nozzles can be removed and cleaned

11 Engineering Requirements

12 Benchmarking- 3D Printers

13 Benchmarking- Single Screw Extrusion

14 Systems Analysis

15 House of Quality: CR Analysis

16 Functional Decomposition

17 Concept & Architecture Development

18 Concept Generation

19 Pugh Evaluation Chart

20 Selected Concept Pellet pre-processor Gravity fed pellets through hopper Heating by electrical current Fans for cooling Screw for driving pellets

21 System Architecture Thermal management [Biggest Challenge]

22 Engineering Analysis Needed Heat Equations Conduction: Convection: Radiation: Heat due to Friction: Energy Equations Energy from motor: Energy from heater: Energy to melt plastic: Power to drive screw:

23 Material Properties Material Density (g/cc) Electrical, Resistivity (ohm-cm) Magnetic, Susceptibility (cgs/g) Specific Heat Capacity (J/g- C) Thermal Conductivity (W/m-K) Melting Point ( C) Accessibil ity Cost Effectiveness Aluminum* E readily available $ Acrylic, Extruded** e e readily available $ Arkema Group Plexiglas V052 Acrylic*** special order $$$$$$$ Stainless Steel~ readily available $$ Copper, C~~ E available $$$ Brass~~~ available $$ aluminum oxynitride^ special order $$$$$$$$$$$

24 Extrusion Screw Research L/D Ratio: 20/1 ratio Profile: 3 zones- feed, transition, meter General purpose use a profile Channel Depth: Determined by resign to be processed Helix Angle The helix angle is the angle of a screw flight relative to a plan perpendicular to the screw plane

25 Heating Research Selecting an aluminum heater should be sufficient for the project, although cost and size will be a deciding factor depending on vendor limitations.

26 Heating Research (cont.) An alternative method to heater bands would be to design some sort of microwave chamber to heat the plastic. This concept was developed by NASA to try and 3D print using Lunar and Mars regolith.

27 Grinding Pellets Research Item Name Description Power Cost KitchenAid BCG111OB Blade Coffee Grinder 160w $29.99 Toastess Model # DLCG559 Blade Coffee Grinder 500w $39.99 Espressione Model # 5198 Conical Burr Coffee Grinder 150w $79.99 Cuisinart Model # DLC-1BCH Blade Food Processor 250w $29.95 Kyocera Model # CM-50 CF Manual Coffee Grinder Manual $47.00

28 Test Plan Outline Temperature Verification Use thermocouples to confirm that the temperature of the heater, melted plastic, and nozzle tip is up to specifications Power Management Ensure that the drive motor, heater(s), and any auxiliary system have enough power to allow the head to operate for the desired run time Uniform flow Determine flow rate out of nozzle Pellet grinding Determine acceptable grain size for ground pellets to prevent any clogging and find a way to consistently achieve it

29 Risk Assessment

30 Risk Assessment Cont. Likelihood Severity Scale 1 - cause is unlikely to happen 1 - impact on project is very minor, will still meet deliverables on time and within budget 2 - cause could conceivably happen 2 - impact on project is noticeable, will deliver reduced functionality, go over budget or fail to meet req. 3 - cause is very likely to happen 3 - impact of project is severe, will not meet req.

31 Project Plan (Weeks 3-6)

32 Project Plan (Weeks 6-9)

33 Project Plan (Weeks 7-9)

34 Questions?