analogue processes, additive manufacturing and...
TRANSCRIPT
Analogue Processes,Additive Manufacturing
andRepRap
Adrian Bowyer
9 March 2012
5 ways to make things
1. Cut
5 ways to make things
2. Bend
5 ways to make things
3. Mould
5 ways to make things
4. Add
5 ways to make things
5. Grow
Additive Manufacturing Example
Fused Filament Fabrication(Fused Deposition ModellingTM)
SomeAdvantages
SomeDisadvantages
Control
CutQuite fast,
Quick shape change
Complicated shapes difficult
Difficult
Bend No waste Limited shapes Difficult
Mould Very fast, no waste
No shape change
Not needed
AddAny shape,
quick change, no waste
Slow Easy
GrowFree(ish),et fast
Materials, not products
Not well understood
Comparison
Control - why is cutting hard and adding easy?
Types of geometric complexity
Control - why is cutting hard and adding easy?
5-D Path Planning 2-D Path Planning
Additive techniques
Stereolithography
Additive techniques
Laminated object manufacturing
Additive techniques
Selective Laser sintering
Additive techniques
Powder printing
Additive techniques
Inkjet 3D printing
Additive techniques
Microscopic stereolithography
Competitive subtractive techniques
Meso machining
HSS + ion beam
Machined featuresSome things never change
STL Formatsolid my_am_object facet normal 0.000000 0.000000 1.000000 outer loop vertex 2.394684 0.987658 1.491202 vertex 2.492724 0.705324 1.491200 vertex 13.910414 3.727284 1.491202 endloop endfacet facet normal 0.000000 0.000000 1.000000 outer loop vertex 2.319906 1.151621 1.491200 vertex 13.910414 3.727284 1.491202 vertex 12.471736 7.200560 1.491202 endloop endfacet...
1. Established at the start of the industry2. Ubiquitous3. Poorly designed
Much improved version:
Hod Lipson et al.:Additive Manufacturing File (AMF)
Slicing at height Z1. Compute line segments from Z plane and STL triangles2. Join segments to make polygons (!)3. Offset polygons4. Infill polygons with cross- hatch5. Record results in file
Tiresome (but not hard) with STL, easy with bitmap or CSG
Support calculation1. Slice top down2. Support at layer N for stuff above:
SN = (S
N+1 U L
N+1) – L
N
3. Reverse layers → bottom up at the end.
Easy if model and layer are: CSG/Boolean Bitmap
Hard if they are B-rep:PolyhedraPolygons
Strengths and weaknesses
Fused Filament Fabrication
Easy to implement
Multiple materials
Needs support
Coarse
Strengths and weaknesses
Stereolithography
Quite easy to implement
Fine
Expensive resin
Single material
May need support
Strengths and weaknesses
Layered object
Cheap raw materials
Warping
Single material
Needs support
Strengths and weaknesses
Selective Laser Sintering
Polymers and metals
No support
Intrinsically expensive
Single material
Strengths and weaknesses
Powder printing
Easy to implement
No support
Colour
Weak products
Single material
Strengths and weaknesses
Inkjet 3D printing
Quite easy to implement
Multiple materials
Colour
Very slow
Needs support
Strengths and weaknesses
Microscopic stereolithography
Only one that works at this scale
Conceptually simple
No support
Needs exceptional precision
Single material
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.
RepRap is a self-replicating 3D printer
RepRap
RepRap Facts
● RepRap can copy about half its own parts.● The other half: hardware shops and on-line.● Cost of all the materials $500.● Working volume: 200 x 200 x 140 mm3.● Material: most plastics.● Print rate: 19 ml/hour (one day to replicate).● Licence: GPL.
RepRap Makes
http://thingiverse.com
RepRap Makes
http://thingiverse.com
4
The biggest difference
Biology – mutualist symbiosis
RepRap = flowersPeople = insectsGoods = nectar
Anyone with a RepRap can make another RepRap for a friend
29 May 2008
It's like MP3 music sharing, but for real solid stuff...
...ultimately any stuff
Personal manufacturing: destroyer of industry
London 1943
Destroying Things
London 2012
That way never works
The Arrow of Time
Alwaysworks
The Arrow of Time
The Arrow of Time
The Future?Everyone in the developed world runs their own
CD pressing plant
The Future?Everyone in the developed world runs their own
CD pressing plant
Photographic Lab
The Future?Everyone in the developed world runs their own
CD pressing plant
Photographic Lab
And printing press
The Future?
Why not their own factory...
The Future?
...that makes more factories?