2. What is 3D printing?
• 2D printing means printing on a surface(2D), e.g. paper printer
• 3D printing means printing solid objects by adding materials layer by layer
• Input a 3D-model
• Printing by printer
• Can use plastic, polymers, or even metal
3. History
• Actually not a new technology
• Charles Hull invented in 1984
• Become popular in recent years
• Due to advanced technology and lower cost
4. Pros & Cons
• Pros:
• Fast prototyping
• Lower costs
• Less setup and wasted materials comparing to
Molding(注塑成型), forging(鍛造) and
casting(鑄造)
• Cons
• Small size
• Few choices of materials
• Slow printing
5. Technology
• Extrusion – Fused deposition modeling(FDM)
• Heat and melt the materials first
• Then “extrude” material layer by layer
• Can use different kinds of materials (mostly plastic and clay)
• Used by the 3D printer in the IT Clinic
• Inexpensive BUT
• Slow and not accurate
6. • Light polymerized - Stereolithography
• Laser shoot on liquid photopolymer
• Liquid react with laser and become solid
• Accurate and can print large object, BUT
• Laser is dangerous and expensive
7. • Powder Bed - Selective heat sintering (SHS) / Selective laser sintering (SLS)
• Apply heat or laser on thermoplastic powder
• Powder sinter (but not yet melt)
• Very complicated and expensive
8. • Powder Bed - Direct metal laser sintering (DMLS)
• Similar to SLS
• BUT used on metal
• Powder Bed - Selective laser melting (SLM)
• Similar to SLS
• BUT will melt the metal powder
• Can print very hard materials, e.g.Titanium alloys, stainless steel
9. • Powder Bed - Powder bed and inkjet head 3D printing (3DP)
• Similar to SLS
• BUT use liquid binding material to combine the powder instead of laser
• Faster than laser
• BUT the powder may stick on the object
10. • Laminated object manufacturing (LOM)
• Use laser cuter to cut the adhesive-coated sheet of materials
• Low cost
• Can build large part BUT
• Less accurate than SLS
11. • Other technologies
• Robocasting or Direct InkWriting (DIW)
• Digital Light Processing (DLP)
• Electron-beam melting (EBM)
• Electron Beam Freeform Fabrication (EBF3)
12. 3D printer brands
• Makerbot (used in IT clinic)
• Movehand (a HK company)
• Tiertime
• Velleman
13. 3D modeling
• A 3d model file is STL file, e.g. ABC.stl
• Can use Computer-aided design (CAD) or 3D modeling software to build
• OR simply download from the internet!
