Manufacturing
Renaissance: Ubiquitous Instant Production (Part-II):
The
Rapid Manufacturing (RM) Industry is Born!
If
it were possible to tag one man with firing up the RM revolution; it would have
to be the bold and innovative Charles ‘Chuck’ Hall. Chuck qualifies,
because in 1986 he patented the much acclaimed workhorse Stereolithography (SLA);
the original RM archetype. The system was first introduced in 1991, what was
back then deemed as a Buck Roger’s toy and re-selling at a whooping
five-hundred-thousand dollars!
But
toy it was not! The breakthrough device was the first system ever
to produce physical 3D models by so-called additive processes. The SLA machine
used beams of ultraviolet laser light on curable liquid photopolymer resins, in
turn using cross-linking to create a solid, layer-by-layer. After the pattern
has been traced, the SLA's elevator platform descends by a distance equal to
the thickness of a single layer (typically 0.05 mm to 0.15 mm); then, a blade
sweeps across the section of the platform; re-coating it with fresh material.
On this new liquid surface, the subsequent layer pattern is traced, joining the
previous layer. A complete additive 3D component is formed. After being built,
parts are immersed in a chemical bath in order to be cleaned of excess resin
and are subsequently cured in an ultraviolet oven.
Industry Key
Technologies and Practitioners
The legacy from the original SLA ferment
has been frenetic. As a large number of distinct RM platform innovations have
emerged over the last two decades: Fused Deposition Modeling; Laminated
Object Manufacturing; Selective Laser Sintering; Laminated Engineering Net
Shaping and Electron Beam Melting are some of the bigger themes.
An abundance of RM Enterprises have
formed and grown in and around this new industry: 3D Systems, Stratasys, EOS,
Z-Corporation, Materialise, Arcam, Shapeways, Optomec, ExOne, Fab@Home, MakerBot, ReaLizer, RepRap, Shapeways,
Digital Forming, MGX, Ultimaker, Builder, Witbox,
Leapfrog, Felix and more on the horizon!
I will come to several of these firms
and their technologies below. However, an in-depth analysis of each company
is beyond the scope of this book. I would suggest Googling each firm
for a deeper look.
|
Rapid
Additive Prototype Manufacturing.
Quantum
physicists oft pose that the Universe has not merely three-dimensions,
plus one other we call time; but eleven! When one tries to think of a
multidimensional Universe, it tends (or at least for me) to boggle the mind.
That we can at least see three of the dimensions (up, down, and sideways) and experience the fourth (the alarm clock
going off in the morning). But Q-physicists are adamant that the other 7
dimensions are very tiny and folded-up inside each other in a kind of
complicated origami space-field. Mind boggling! But what does that have to do
with RM?
Over
that last two decades the range of materials available for RM has burgeoned
from the original low-resolution homogeneous photopolymer to a broad array of
performance heterogeneous materials athwart of co-polymers, metal alloys, fine
grained ceramics and hybrid composites.
Objects
Connex 3D by Stratasys, for example, is
a printing system that has the capacity to fabricate so-called Digital
Materials that give predetermined mechanical properties and parameters
which emulate the final manufactured product intended material performance.
Two
discrete materials, picked from 17 primary materials can fuse in 136 potential combinational
universes [(17(17-1)/2=136]. A Connex part can be printed with 14
material multidimensional combinations in one 3D printing procedure (my 11
dimension Universe metaphor – now I get it!). The material can simulate
elastomeric behaviours ranging from Shore hardness 27-to-95, ridged, tough to
engineering grade ABS.
This
begins to illustrate the new technical capability for such RM technology. A
mere 10 years ago, this would have been quite impossible.
Express
Metal Fabrication: Integral Parts without Expensive Tooling.
As
a young design engineer I used to tease the toolmakers I worked with when
making design modifications. There is an age old problem where if a component
feature, like an aperture or diahole had to be increased; then the core inside
the mould tool had to be increase in size as well. And that invariably meant
the core had to be replaced with a larger hub, increasing time and capital
costs. ‘When are you going to invent a metal on-tool,’ I would moan. But
that was back in the 1990s.
Now comes a host of ‘metal-on’ RM equipment.
One being Arcam EBM® Electron Beam Melting, which builds
up metal powder layer-by-layer, fully dense metal components, which is melted
by a powerful electron beam. Each layer is melted to the exact geometry defined
by a CAD model.
This is a new paradigm for industrial manufacture as metal
is added instead of removed, as in the case in traditional machining. EBM allows for the building of parts
with very complex geometries without tooling and fixtures; and without
producing any waste material. Good for reducing capital costs, good for the
environment.
EBM provides enormous benefits for the entire production
value-chain. Geometrical design scope is freed as envisioned, doing away with
traditional manufacturing constraints (undercuts, drafts, secondary surface
finishes, time and cost consuming assembly), translating to extremely
light-weight designs, reduced part count, and improved integrity without
expensive casting or forging stock.
Revolutionary Physical Geometric Capabilities.
Rapid Manufacturing systems are giving new life to
spaces and shapes once only relegated to the imagination. Real components are
being made that were thought quite impossible geometrically 10 years ago. You
may have seen 2D pictures of the inverse-impossible loop that folds itself up
inside itself? Now, 3D Systems are printing out seemingly impossible convoluted
geometric pattern. I think M.C Escher would be dumbfounded. New,
strange and counterintuitive geometry is now being explored in
physical reality.
By simulating nature’s organic structured lattice, convoluted organic forms are facilitating designs that are lighter and have more efficient structures which have significant strength to wait ratio improvement (Now you know why nature’s humble Bumble Bee can fly, when it is not suppose too!).
3DP Optical Systems.
Recent developments in 3DP technology have enabled the fabrication of high resolution transparent plastics with similar optical properties to Plexiglas. One-off 3DP optical elements can be designed and fabricated literally within minutes than conventional mould manufacturing; greatly in-creasing accessibility and reducing end-to-end production time.
Lighting products such a focusable spotlights, photometry systems such photometric measurement or high precision telescopic lens are beginning to me made on the spot for pennies with no tooling capital investment costs.
Recent developments in 3DP technology have enabled the fabrication of high resolution transparent plastics with similar optical properties to Plexiglas. One-off 3DP optical elements can be designed and fabricated literally within minutes than conventional mould manufacturing; greatly in-creasing accessibility and reducing end-to-end production time.
Lighting products such a focusable spotlights, photometry systems such photometric measurement or high precision telescopic lens are beginning to me made on the spot for pennies with no tooling capital investment costs.
Protos, a
custom eyewear venture established in San Francisco, produce sunglasses via
3DP. Protos aim for striking designs, cost prohibitive through conventional
manufacturing methods. Finding a pair of rays that fit and looks kool is, for
many Californian types, a niggling problem, often ending in a compromise on the
customer’s part. The design strategy is to tailor a fit based on an
individual’s facial measurements uses advanced manufacturing such as selective
laser sintering, 3D scanning and parametric 3D modelling to develop and
manufacture customizable products that would not exist by other means.
Multifunctional Inks and
Multifunctional Deposition Heads.
The next leap-on in the RM
world is Multifunctional Inks and Multifunctional Deposition Heads. ‘Functional’ at its entry level means
parameters like tough, inert or transparent (above). It can also mean
insulating (dielectric), semiconducting and conducting. However, where this
process gets interesting is the creation of Multifunctional Materials!
Otherwise known as smart or dynamic materials; multifunctional materials have
specific active behaviours and properties. In turn, such n-materials are
made from multifunctional inks which enable the manufacture of complex active
components with three-dimensional gradients and differentiated structures; say
from sliver-to-plastic-to-ceramic-to-carbon, et al. Resulting in paradoxical differentiated
fine-grain isotropic multimaterial structures.
IFAM is a German
R&D led materials manufacturer, developing integrated 3DP techniques that
utilise multifunctional-inks to produce gradient materials with local phases
(differentiated composition), giving customized and integrated component
functions. 3D printing of discrete electrical components such resistors and
diodes; while some headway has been achieved with active electrical components
such as simple integrated circuits.
Clearly,
such smart enabling inks need a way of being deposited: hence, multiplicative
deposition heads. These enable multiplicative processes, not just additive
processes. One of the most disruptive technologies here is the so-called 3D
inkjet-multihead. The multihead is one of the prime enabling technologies
for geometrically complex, differentiated gradients and active multifunctional
materials. The goal of multihead deposition is to be print layer by layer, at
the sub-micron level, without any post processing.
Together,
multifunctional-inks and multihead-deposition means a
major milestone for RM technology: to print out complete functional components
and assemblies in one hit. For example, the notion of printing out a working
television remote controller may seem outlandish, but a team of engineers at
the University of California are developing multiplicative inkjet heads that
does just that. Instead of fabricating a plastic housing and then arduously
populating it with components, circuit boards, and connectors, a complete and
fully assembled functional device is printed in one hit.
Commodity
devices such as handheld touches, radios, mobile phones or pocket calculators
will emerge as fully working systems, in one hit. A television remote
controller printed as a single continuous multifunctional assembly would
contain the buttons, a polymer-based infrared emitter and polymer-based
electronics, as well as the light-emitting device. Clearly the way artefact are
made are about to go through radical transformation.
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