Analogue Processes, Additive Manufacturing and RepRap

Transcription

1 Analogue Processes, Additive Manufacturing and RepRap Adrian Bowyer 9 March 2012

2 5 ways to make things 1. Cut

3 5 ways to make things 2. Bend

4 5 ways to make things 3. Mould

5 5 ways to make things 4. Add

6 5 ways to make things 5. Grow

7 Additive Manufacturing Example Fused Filament Fabrication (Fused Deposition ModellingTM)

8 Comparison Some Advantages Some Disadvantages Control Cut Quite fast, Quick shape change Complicated shapes difficult Difficult Bend No waste Limited shapes Difficult Mould Very fast, no waste No shape change Not needed Add Any shape, quick change, no waste Slow Easy Free(ish), Materials, not products Grow t e fast Not well understood

9 Control - why is cutting hard and adding easy? Types of geometric complexity

10 Control - why is cutting hard and adding easy? 5-D Path Planning 2-D Path Planning

11 Additive techniques Stereolithography

12 Additive techniques Laminated object manufacturing

13 Additive techniques Selective Laser sintering

14 Additive techniques Powder printing

15 Additive techniques Inkjet 3D printing

16 Additive techniques Microscopic stereolithography

17 Competitive subtractive techniques Machined features Some things never change HSS + ion beam Meso machining

18 STL Format solid my_am_object facet normal outer loop vertex vertex vertex endloop endfacet facet normal outer loop vertex vertex vertex endloop endfacet Established at the start of the industry 2. Ubiquitous 3. Poorly designed Much improved version: Hod Lipson et al.: Additive Manufacturing File (AMF)

19 Slicing at height Z 1. Compute line segments from Z plane and STL triangles 2. Join segments to make polygons (!) 3. Offset polygons 4. Infill polygons with crosshatch 5. Record results in file Tiresome (but not hard) with STL, easy with bitmap or CSG

20 Support calculation 1. Slice top down 2. Support at layer N for stuff above: SN = (SN+1 U LN+1) LN 3. Reverse layers bottom up at the end. Easy if model and layer are: CSG/Boolean Bitmap Hard if they are B-rep: Polyhedra Polygons

21 Strengths and weaknesses Fused Filament Fabrication Easy to implement Multiple materials Needs support Coarse

22 Strengths and weaknesses Stereolithography Quite easy to implement Fine Expensive resin Single material May need support

23 Strengths and weaknesses Layered object Cheap raw materials Warping Single material Needs support

24 Strengths and weaknesses Selective Laser Sintering Polymers and metals No support Intrinsically expensive Single material

25 Strengths and weaknesses Powder printing Easy to implement No support Colour Weak products Single material

26 Strengths and weaknesses Inkjet 3D printing Quite easy to implement Multiple materials Colour Very slow Needs support

27 Strengths and weaknesses Microscopic stereolithography Only one that works at this scale Conceptually simple No support Needs exceptional precision Single material

28 Additive Manufacturing The most versatile manufacturing technology we have. Can make shapes impossible with any other technique. Only been going 30 years. Computationally simple. Some AM machines very cheap. Basis of RepRap the first replicating production machine in the World.

29 RepRap RepRap is a self-replicating 3D printer

30 RepRap Facts RepRap can copy about half its own parts. The other half: hardware shops and on-line. Cost of all the materials $ Working volume: 200 x 200 x 140 mm. Material: most plastics. Print rate: 19 ml/hour (one day to replicate). Licence: GPL.

31 RepRap Makes

32 4 RepRap Makes

33 The biggest difference

34 Biology mutualist symbiosis RepRap = flowers People = insects Goods = nectar

35 Anyone with a RepRap can make another RepRap for a friend 29 May 2008

36 It's like MP3 music sharing, but for real solid stuff......ultimately any stuff

37 Personal manufacturing: destroyer of industry London 1943

38 Destroying Things London 2012 That way never works

39 The Arrow of Time Always works

40 The Arrow of Time

41 The Arrow of Time

42 The Future? Everyone in the developed world runs their own CD pressing plant

43 The Future? Everyone in the developed world runs their own CD pressing plant Photographic Lab

44 The Future? Everyone in the developed world runs their own CD pressing plant Photographic Lab And printing press

45 The Future? Why not their own factory...

46 The Future?...that makes more factories?