Embed Size (px)
Citation preview
© 2012
Digital to Physical: ALM for Diverse Sectors
Dr Ben Wood, WMG, University of Warwick
@benjaminmwood
© 2012
Agenda
0845-0915 Registration, tea and coffee
0915-0930 Welcome and Introductions
0930-1100 Physical to Digital – Laser scanning and producing a CAD file
1100-1115 Refreshments Break
1115-1245 Digital to Physical – 3D printing and how to deal with ‘bad’ CAD
1245-1330 Lunch
1330-1500 Low Volume Manufacturing – The gap between prototype and product
1500-1600 Adding Functionality – Update on latest polymer technologies
1600 on 1 to 1s with the Polymer Innovation team – individual projects
© 2012
What are we going to talk about?
© 2012
Introductions
– Dr Alex Attridge
& Ercihan Kiraci
– Dr Greg Gibbons
– Dr Kylash Makenji
© 2012
Introductions
• Name
• Company
• Why you’re here
• What you would most like to get from today
© 2012
Physical to Digital
Scanning technologies and
creating useful data
© 2012
Physical to Digital
• Contents
–Why go from physical to digital?
– Technologies for collecting data
• Laser Scanning
• X-Ray Computed Tomography (CT)
• Structured Light and Photogrammetry
– Laser scanning demo
–Case study examples
© 2012
Why Physical to Digital?
• There are a number of reasons: – Measurement/CAD comparison
– Simulation/virtual testing
• CFD for fluid flow or aerodynamic modelling
• FEA for stress analysis
– Create tooling from a physical prototype
– Benchmarking competitor product
– Reverse engineer to surface model or CAD
© 2012
Why Physical to Digital?
Colour chart and measurements showing deviation from CAD
© 2012
Why Physical to Digital?
Creation of an FE mesh for a fatigue crack specimen to help understand the effect of the crack on performance of the part
© 2012
Why Physical to Digital?
Creation of a digital surface model from a 1/3 scale Le Manns Prototype class clay model, to enable a full-scale physical model to be machine cut for use as a plug for the bodywork mouldings
© 2012
Why Physical to Digital?
Internal benchmarking of an automotive switchgear mechanism, carried out as part of a “switch feel” customer clinic study
© 2012
Why Physical to Digital?
Reverse engineering to CAD of a suspension component from a classic rally car to improve strength and compatibility with modern suspension leg/damper technology
© 2012
Collecting data
• Different technologies for capturing 3D surface geometry: – Laser scanning
– X-Ray CT scanning
– Structure light scanning (white/blue)
– Photogrammetry
• Different technologies for different applications
© 2012
Laser scanning
• Typically utilises Class 2 red laser light
• Move laser “stripe” over the surface to be measured
• “Stripe” is actually made up of hundreds of points
• Point cloud of data collected – x, y, z, co-ordinates
• Post-processing required but easy to create mesh
© 2012
Laser scanning
Point Cloud (XYZ)
Accuracy 10µm – System Accuracy approx 40µm
75 stripes/sec - 1000 points/sec data collection
Digital Calibration for every point captured
© 2012
Multiple lasers
Line Scanner Cross Scanner
© 2012
Laser scanning
Manual Measurement Arm (Faro, Nikon, Roma etc.)
Optical CMM
On-CMM laser scanning head
© 2012
Laser scanning
• Good for collecting complex surface geometry
• Software can identify and characterise features
• CMM or portable systems
• Simple to use – quick results
• Data captured not perfect – line of sight issues
© 2012
X-Ray CT scanning
• Uses X-ray technology to create a digital 3D model of the object scanned
• Similar concept to medical CT, but much higher powered and much more accurate
• Limit to size and density of object to be scanned
© 2012
Projection Image at angle 1 deg.
Projection Image at angle 2 deg.
3D object reconstruction by back-projecting the projection images - Using reconstruction software
Reconstructed 3D model visualization as stack of images - Using visualization software
STL format export
DICOM Image series export
Point cloud data export
CT Scanning of an object to get Projection Images - Using XT 320 H Machine
X-ray source
Rotary table
Object with a cylindrical hole inside
Detector
Projection Image on screen
© 2012
X-Ray CT scanning
• Excellent technology for internal inspection
• Typically good quality data generated
• Very large file sizes
• Struggles with big changes in density
© 2012
Structured light
Traditionally white light More recently blue light Projects pattern on to surface Pattern is distorted and captured
© 2012
Structured light
GOM Phase Vision
Breuckmann
© 2012
Structured light
Often used to characterise panels, clay models, people(!) etc. Good for large surfaces Not so good for smaller objects Can take a while to set up
© 2012
Photogrammetry
Digital SLR Approx 60 photographs
Cloud-based software 3D digital model
© 2012
Hands-on Demo
• Laser Scanning
• Software
Down to the workshops!
© 2012
Digital to Physical
Additive Layer Manufacturing
© 2012
Digital to Physical
• Contents –Data generation for ALM
• Data sources and examples
• Data repair
– System setup – an overview
– System set-up - practical hands-on)
–ALM – ‘the real deal’
© 2012
DATA GENERATION
05/12/2012 30
© 2012
Data Generation
• All systems use a ‘.STL’ file: – Surface triangulated mesh file representing the
surface of a component
• STL files can be generated from – Directly from export of 3D CAD – Surface scan data – Volumetric (e.g CT data)
• Data from any of these methods may require pre-processing to be useable in ALM
© 2012
STL files from CAD
• Use ‘export ‘or ‘save as’ function to create STL
© 2012
STL files from surface scan • Scan of iPhone 4 case:
© 2012
STL from CT/MRI scan
© 2012
Errors in STL files • Some STL files can be very poor quality
• Particularly from scan or CT…
…but can be poor CAD:
– Missing surfaces
– Gaps
– Intersecting surfaces
– Inverted triangle
normals
© 2012
Errors in STL files
• Most ALM systems will not tolerate this and will require a ‘perfect’ STL file
– One single continuous surface
– All surface normals are correct
• Software is available to fix errors relatively easily
05/12/2012
© 2012
SYSTEM SETUP – AN OVERVIEW
37
© 2012
System Setup – Overview • STL file is the starting point for
any ALM system
• STL may contain colour information (color STL)
– Currently only ZCorp systems
– Mcor about to release colour system based on bonded paper sheets (Iris)
• VRML colour files are also accepted in ZCorp systems
© 2012
System Setup – Overview • All system have proprietary software,
e.g: – Insight (Stratsys – FDM) – Objet Studio (Objet - MJM) – Zprint (ZCorp – 3D Printing)
• Functions available: – Operators on model
• E.g. rescale, rotate, translate, copy
– Support generation – Selection of build parameters
• Usually defaults, but can ‘play’ on some systems
– Obtain time, material usage information • Useful for quoting purposes
© 2012
System Setup – Overview • Some systems require a support
structure to be generated
• This is always necessary for non-powder bed based systems
• Support acts as a surface to accept the next layer
• The system interface software generates this automatically
• Some control on the type of support is allowed, usually to minimise material usage – Density – Shape
© 2012
System Setup – Overview • Additional functionality is available with the ‘new’ multi-
material printers, giving the ability to: – insert an assembly and define the type of material of each part in the
assembly
– overcoat with materials
– choose glossy or matte surface finish
© 2012
ADDITIVE MANUFACTURING– THE REAL DEAL
42
© 2012
Additive manufacturing– the real deal
• Materials
• Accuracy
• Resolution
• Sizes
• Time
• Costs
• ‘non added value’ activity
© 2012
Polymers • Most common thermoplastics are:
– SLS (PA, PS)
– FDM (ABS, PLA, PC, PEEK)
• Most common thermosets are: – Acrylic (MJM)
– Epoxy (SLA)
– Wax-like (for investment casting)
• The HDT of FDM materials is equal to the IM grade
• The HDT of other polymers is usually lower than 500C
• High temperature polymers are available – PEEK (SLS)
– PPSF, ULTEM (MJM)
• Transparency is available but not for FDM and SLS – Translucency is available for FDM (ABSi - Methyl methacrylate-acrylonitrile-butadiene-
stryrene copolymer)
• Fire retardancy is available (most systems)
• Biocompatibility is available (non-implantable) for most systems
© 2012
Metals
• Most metals processed using SLS
• Wide range of commercial materials
– Ti, Ti alloys, stainless steel, Inconels, CoCr, Maraging steel, tool steel, aluminium…
• Now systems processing Ag, Au, Pt (EOS-Cookson Metals tie-up)
• Mechanical properties usually approach or match those of wrought materials
© 2012
Accuracy, Resolution
• Resolution and accuracy are not the same!
• Accuracy and resolution are complex and are highly dependent on system and component size, and on quality of calibration
05/12/2012
Accuracy Resolution
x y z x y z
SLS metal
30 30 20 100 100 20
SLS polymer
100 100 100 50 50 50
MJM 20 20 16 40 40 16
3DP 250 250 89 100 100 89
© 2012
Size
• Polymers – Wide range of size capabilities (50mm-3m+)
– Small bed sizes often have higher resolution
– Large bed sizes often have faster build rates
• Metals – Most metals systems have beds
<300x300x300mm
– Soon to be released have 500x500x300mm
© 2012
Time
• Time is very difficult to assess from an STL file since:
• Time is dependent upon:
– Part volume
– Part dimensions
– Part orientation
– Material used (even in the same process)
– Level of finishing required
– How much you want to pay (premium for queue jumping)
© 2012
Costs (using a bureau)
• Not easy to assess just from an STL file since:
• Cost is very much dependent upon: – Volume of the component (amount of material)
– Part dimensions
– Cost of the material
– Amount of support material
– Resolution required (number of slices)
– Orientation required (taller the dearer)
– Number of parts required (often cheaper per part to have multiples – especially for SLS)
– Level of finish required
© 2012
Costs (in-house)
• If you have system in-house, need to consider: – Maintenance costs – Material costs (including scrap, waste) – Consumables costs – Infrastructural costs – Labour costs (set-up and clean-down)
• Costs can vary widely depending on the system – System - £500-£1m+ – Maintenance – £100 – £30k PA – Material - £1 - £600 /kg – Infrastructural - £0 - £100k + – Labour - £5 - £200 per part
© 2012
Low Cost Systems • Recent huge rise in ultra-
low cost systems – Makerbot, BFB, Cubify …
• Based on FDM technology
• £500 - £2,500
• Material costs ~£20/kg
• No dedicated computer
• No training
• Simple post-processing
© 2012
Low Volume Manufacturing: Bridging the Gap
Dr Ben Wood & Dr Kylash Makenji
IIPSI
© 2012
Outline
• Identifying the problem
– How to go from prototype to production?
• Direct manufacturing methods
• Rapid Tooling
– Indirect
– Direct
• Live demo of direct tooling
© 2012
CNC Machining
The Problem
Tooling Cost
Number of Parts
10,000 100,000 1 1,000,000+ 1000 100
ALM
Injection Moulding
Compression Moulding
Rotational Moulding
Low Volume Manufacturing
© 2012
What is Rapid Tooling?
• Early definition of Rapid Tooling:
“a process that allows a tool for injection moulding and die casting operations to be manufactured quickly and efficiently so the resultant part will be representative of the production material.” - Karl Denton 1996
• With Rapid Tooling now covering a wider range of
applications, this has generalised to:
“a range of processes aimed at reducing both the cost and time for
the manufacture of tooling.”
© 2012
Classification of Rapid Tooling
• Indirect
– Use of a Rapid Prototype (RP) pattern to manufacture a tool in a secondary operation
• Direct
– Directly produce the tool using a layer-additive process
© 2012
Indirect Rapid Tooling
• Cast tooling
– Cast resin tooling
– Cast metal tooling
– Cast ceramic tooling
• Metal spray tooling
– Kirksite thermal spray tooling
– Rapid Solidification Process tooling
– Sprayform tooling
• Indirect laser sintered tooling
– 3D LaserForm process
• 3D Printed tooling
– Extrude Hone Prometal
© 2012
Cast Resin Tooling
• Obtained by two primary methods: – Room temperature vulcanised silicone
– Rigid resin tooling
• Room temperature vulcanised silicone – Silicone rubber tools for vacuum casting of
(generally) polyurethane parts
– RP model employed as master pattern
– Multistage process
– Resin parts vacuum cast or injected into tool
– Expensive materials
– Low volume (~30 parts) / extremely rapid (1-2 days)
© 2012
Cast Resin Tooling
• Obtained by two primary methods: – Room temperature vulcanised silicone
– Rigid resin tooling
• Rigid resin tooling – Aluminium filled epoxy resin tools used for
injection / blow moulding
– As for RTV silicone, RP model used as master pattern
– Multistage process
– Difficult and slow to mould parts
– Volumes up to ~500 / very rapid (3-5 days)
© 2012
Direct Rapid Tooling
• Direct metallic tooling
– Direct laser melted metallic tooling • EOSint M DirectTool
• MCP Selective Laser Melting (SLM)
• Direct polymeric tooling
– 3D Printed mould inserts • Object Connex 260 • Fortus FDM
© 2012
Laser Melted Metallic Tooling
• DirectTool – Latest system EOSINT M270
– Process:
• Direct laser melting of metal powder
• Ability to polish to mirror finish
– Materials:
• DSH20 (tool steel)
• DS20 / 50 (20mm and 50mm steel)
• DM20 / 50 (20mm and 50mm bronze)
– Very hard tooling possible (42HRc)
– Very high accuracy (~50mm) / 20mm layers
– Conformal cooling channels
• Many similar processes, 2 most employed are: – DirectTool – EOS GmbH – Selective Laser Melting (SLM) – MCP Inc
© 2012
Laser Melted Metallic Tooling
• Selective Laser Melting – Latest system „Realizer‟
– Process:
• Direct laser melting of metal powder
• Ability to polish to mirror finish
– Materials: • Any metallic powders 10-30mm
• Stainless steel most common
– Very high accuracy (~50mm) / 50mm layers
– Conformal cooling channels
• Many similar processes, two most commonly employed are: – DirectTool – EOS GmbH – Selective Laser Melting (SLM) – MCP Inc
© 2012
3D Printed Polymer Inserts
• Manufacture a tool insert by ALM
– Accurate
– Good surface finish
– Very rapid (30 mins-2 hours)
© 2012
3D Printed Polymer Inserts
• Ready for mass production
– Injection mould tooling
– Lower cost ‘pocket’ tool
– Can be used with wide range of inserts
• Easy, quick and inexpensive to make changes
© 2012
INJECTION MOULDING TOOL INSERTS
Hands - On
© 2012
Polymers
© 2012
Material Compatibility
© 2012
Process Comparison
Process Capital
Equipment Cost
Production Rate Tooling Cost Part Volumes
Compression Moulding
Low Slow Low 100 – 1 mill
Vacuum Forming Medium Medium Medium 10,000 – 1 mill
Injection Moulding High Fast High 10,000 – 100 mill
Extrusion Medium Fast Low – Medium Med - High
Blow Moulding Medium Medium Medium 1,000 – 100 mill
Rotational Moulding
Medium Slow Medium 100 – 1 mill
© 2012
Summary
• Many potential manufacturing routes for low volume
– Right choice depends on part and material
• ALM can be used for much more than prototyping
– Key to most rapid tooling methods
© 2012
Adding Functionality
IIPSI Capabilities and State of the Art
© 2012
Outline
• Shape memory polymers
– Active disassembly
• Printed and plastic electronics
– Conductive polymers
– Low cost applications
– Integration
• What would you like to see?
© 2012
Shape Memory Polymers
• Can be ‘programmed’ to change shape when given a trigger
• High material cost = niche applications
Heat
FORCE
Mould part
Force into temporary
shape Cool
Restrain
Set temporary
shape Heat
Return to original shape
© 2012
SMP Research Focus
Medical
Aerospace/defence – morphing wings Outer Space – Zero Gravity
© 2012
SMPs for SMEs!
• ‘Active’ disassembly
– Ideal for automotive, consumer electronics
• Automatically release at end of life
– Materials separation, recycling
• Low complexity
– Maximise added value
© 2012
PLASTIC AND PRINTED ELECTRONICS
© 2012
Conductive Polymers
• Actual conductive polymers not common
– Difficult to process, not like plastics
– Normally dissolved in solvent
• Applications in PV and EL/OLED
– Useful as part of a printed or plastic electronic component
© 2012
Plastic and Printed Electronics
• Growth area
– Funding opportunities
• Costs reducing
– Expensive materials vs volume production
• Key applications
– Display technology
– ‘Smart’ Packaging
– IoT
© 2012
• Electroluminescence (EL)
– Low energy, low heat lighting
– Simple circuit
PEDOT-PSS transparent electrode
Zinc Sulphide Phosphor
Dielectric
Reflective (silver) rear electrode
Surface
+ve
-ve
LIGHT
Plastic Electronics
© 2012
EL Applications
© 2012
Low Cost Plastic Electronics
Airbrush Method
© 2012
Low Cost Plastic Electronics
Screen Printing Type Method
© 2012
Low Cost Plastic Electronics
Direct In-Mould Layer Application
© 2012
Low Cost Plastic Electronics
Post Mould Layer Application
© 2012
• Bespoke system hybridising MJM with syringe deposition – 2 x 512, 14pl nozzle heads,
individually addressed
– High viscosity liquid dispensing
– Continuous flow for deposition of resins with highly suspended solids
– SmartPump for deposition of higher viscosity resins and pastes at extremely high resolution
Hybrid 3D Printing
© 2012
Hybrid 3D Printing
• Integrated manufacture
– Functional components
– Electronic circuits
• Facilitates adding of functionality and connectivity
– Eg interactive books
– Internet of Things (IoT)
© 2012
Summary
• Complex circuits require expensive kit and specialist knowledge
• Market is growing, costs coming down – Printing technology, roll-to-roll
• Simple circuits achievable with low capital – Layer-by-layer deposition of materials
• Future is in integration – IoT – https://www.youtube.com/watch?v=zG2dvxSKEGU
– https://www.youtube.com/watch?v=Kgw51_PtDSs
© 2012
OVER TO YOU! What would you like to see in the IIPSI?
