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Laser cutting applications of rapid prototyping
Transforming the 2D into the 3D
Isaac Chen – isaacche@usc.edu
Undergraduate student, School of Architecture,
University of Southern California, Los Angles
WRIT-340, Dr. H. Ramsey
Isaac Chen is currently a 4th year architecture major working as a digital fabrication
assistant primarily working with laser cutting machines. His studies include determining
the reproduction of complex forms generated through computer modeling.
Keywords: Laser cutting, digital fabrication,
Suggested Media: http://youtu.be/arjRtCjI9AQ - LaserOrigami demo
Abstract
The future of digital fabrication is rapidly developing industrial and
architectural modeling. Fabricators such as 3D printing and CNC milling utilize
additive and subtractive techniques respectively. Laser cutting is capable being
transformative quickly making 2D sheets turn into 3D objects efficiently.
Similar techniques of small-scale laser cutting can be applied at a large scale
opening up new possibilities in structural and architectural aesthetics.
Introduction
Generally most people jump to the realm of science fiction when thinking about
lasers. Not many are familiar with the practical uses of this technology. Lasers are used for
alignment, writing compact discs, hair removal, surgery, weapons, and barcode scanning
just to name a few applications. A relatively unknown use of lasers is for digital fabrication,
or translation of computer models into physical objects. In industrial manufacturing these
lasers are used to cut materials that have complicated patterns or require highly precise
specifications. Smaller scale laser cutting machines are most often utilized by model
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makers and appear in many architecture schools across the world. These smaller machines
cut mostly paper, wood, and plastic products opening up new design opportunities because
of their efficient nature.
The capabilities of model making have expanded because laser-cutting technology
allows intricate patterns to be developed and modeled pragmatically. In the past models
would need to be hand cut by knives or machines, such as a band saw, and would take
massive amounts of time to complete. With the invention of laser cutting, models can be
constructed in a fraction of the time. Seen below in figure 1, a pattern is generated using
Grasshopper, a digital algorithmic modeling program, to create a complex design. Before
laser-cutting designs like this would be unheard of because of the extensive time and
money needed to make it. These designs carry more visual depth than conventional flat
planes and generate new construction capabilities. Modeling now can be as simple as
inputting line drawings into a machine and receiving a complete finished product.
Fig. 1 Layered laser-cut MDF model [1]:
Physical model-top, line drawing input into machine below
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Basic mechanics
Some uses of laser-cutting machines include cutting, engraving, welding, and
drilling. Specialized diodes convert energy into high intensity lasers. When focused
correctly, they can melt or vaporize material at a stationary focal point. Vaporizing
numerous overlapping points creates the illusion of a continuous line and thus makes a cut
in a material. One limitation is that the focal depth is fixed on a horizontal plane according
to the axial movement of the laser head. Maximum cutting thickness is dependent on
material properties and varies greatly. Anything from sheet metal to bread slices can be
cut.
Industrial laser cutting usually applies to metals for architectural and structural
purposes. The main materials cut are mild and stainless steel, aluminum, and copper
varying in thickness up to 20 mm [2]. High-pressurized gas minimizes deformations
resulting in cleaner cuts. As represented in fig. 2 below, gas is injected into the nozzle of the
laser head blowing away any excess material generated from the super heated material.
Fig. 2 – Gas assisting laser cutting parts diagram [2]
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A common machine setup moves on three axes as seen in fig. 3. The laser bed moves
vertically on the z-axis to set up the material on the focal plane. Failure to focus the laser
results in reduced power and an imprecise cut, but this can be used the advantage of the
user. Above the laser bed a laser head is mounted on an elevated horizontal bar which rests
on two rails. The laser head slides left and right on the x-axis while the bar shifts forwards
and backwards on the y-axis with a series of belts and motors. The bi-axial movement can
be then programed to cut a line drawing that a computer generates. The power of the laser
and speed of the laser head then determines how deep a material is cut and how clean the
vaporization process is. Burn marks will generally be a by-product of the cutting process.
- Laser head
Fig. 3 – Three axes setup [3]
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Transforming 2D to 3D
Bi-directional cutting typically limits sheets to a single plane. To turn two
dimensional sheet materials into the third dimensional objects, techniques of puzzling,
layering, and/or folding must be implemented. A single flat sheet can be transformed into
physical volume with occupiable space. Other digital fabricators are 3D printing and CNC
milling. Fabrication techniques have their merits and are chosen to best create the final
effect desired, but some take much longer than others. 3D printing builds layers of material
that are less distinguishable and are can creating smooth volumes; this process is best
suited for additive constructions. A major disadvantage of 3D printing is that is an
extremely long and expensive process that is still in its basic developmental phases. CNC
milling is an opposing technique to 3D printing by instead taking a solid block of wood or
foam and subtracting material by drilling to achieve the final form. This too is a time
consuming process that can take several hours where laser cutting can approximate a
similar form in a few minutes. Laser cutting is the only process of these main modeling
techniques that has the potential to remove and build material while also transforming a
sheet material. It is best used to create abstract representative models of complex forms or
folded surface objects.
Sheet construction
Laser cutting enables precise objects to be cut quickly and accurately with an
emphasis of creating surfaces. Gears, hinges, and cut sheets can be modeled in a computer
and then cut by a laser. Mass production of a hundred differently shaped pieces would take
the same amount time as cutting a hundred pieces that are exactly the same. This allows for
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parametric construction where growing and changing patterns have unique profiles. In the
origami technique of kusudama, sheets of paper are folded into regular polyhedrons that
give dimensionality without adding excess weight or material [4]. The pleating in the sheet
gives structural rigidity and a visually interesting aesthetic. Each polyhedron is the same
size and shape meaning the technique to mass-produce these shapes would be to cut a
template or punching a metal profile. Adding complexity to the pattern, such as a growth
progression from larger to smaller polyhedrons, would result in many different profiles
that are most easily produced by laser cutting. Each piece would require a bonding agent to
connect each piece so this technique mostly only saves on time needed to form materials to
the right shape.
Sectional Layering
Sectional profiles and customized shapes can be cut and stacked together to create a
three dimensional object through layering. The sectional building process is similar to a 3D
printer, but is dependent on the thickness of the material and can build larger objects.
Large-scale applications can build up spaces through a layering of sheet material. In figure
4, sheets of laser cut paper are layered to create depth and is a small-scale example of what
can be produced. Super intricate details do not require a sculptor to chip away at a solid
material and can be produced by the designer rapidly. It is much like printing individual
sheets with holes in them and then stacking them together in order to create a space by
building up the voids. For the real world commercial laser beds can fit whole metal sheets
up to 5 by 10 feet [5]. By intersecting multiple layers intricate apertures can be produced
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with minimal effort. This sectional technique enables three-dimensionality through a
subtractive technique.
Fig. 4 – Laser Cut Paper Stained Glass Windows [6]
Material Folding
Folding material is a more ideal technique to have greater material efficiency.
Three-dimensionality is achieved by creating origami like folds to generate stability and
spaces. The process of construction is streamlined by using bending instead of bonding
multiple pieces together. A single bend can replace the need for several connector pieces
saving time and extraneous materials. Laser cutting can assist bending in a couple of ways.
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First, lasers can partially cut through a material allowing the material to bend more easily
and managing shear stress. Second, applying heat of an unfocused laser can temporarily
softens hard plastics and thin metals so they can be bent into their desired state. Figure 5
demonstrates the ability for cuts and heat deformation to be applied together to produce a
three-dimensional object.
The hybrid cut and folding techniques utilized by LaserOrigami allow quick
prototyping of small objects. The heat of the laser enables a normally rigid sheet material to
be pliable and shaped before becoming rigid again [7]. The rigid sheet is mounted on a so
that when a section of the material is heated it begins to sag. The operator then must bend
the object into the desired fold. Most of LaserOrigami’s prototypes are only tested on
acrylic. If this technique is applied to large sheets of metal on a mobile laser machine, quick
onsite production of shelters can be produced with minimal effort. Pleating a single sheet of
metal can create structural rigidity efficiently. A laser could heat the joint and an operator
can fold the metal like a piece of paper while returning to its original shear strength in the
end once the material has cooled. Eventually this practice can create quick occupiable
forms from solid sheets.
1.
2.
Fig. 5 – LaserOrigami Suspender [7]:
Sequence of sagging deformations of cuts in step 1 and then sagging deformation in
step 2
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Conclusion
Imaging getting sheet of wood and then inputting a set design into a laser-cutting
machine. A few minutes later you have all the pieces to construct yourself a chair by folding
it into place. Highly intensive designs produced in the computer can easily be built giving
users full control over their final product. Mass customization can come without costing
more than its standard counterpart or a single template can be cut hundreds of times each
exactly the same as the one before. As laser technology grows, cutting machines will be able
to be more portable and will eventually be free of material size constraints. Creating threedimensional objects from seemingly flat materials is the strength of laser cutting. Utilizing
the heat transference from lasers to materials will father increase the capabilities of folding
and bending materials in ways that only paper can. As this practice matures more
opportunities for lasers will become part of our everyday lives and create more complexity
in design and fabrication.
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References:
[1] S. Padora, “Roof Addition, Mumbai,” Grasshopper, [online] (Accessed: 15 November
2013).
[2] C. Webb and J. Jones, Handbook of Laser Technology and Applications, Vol. III:
Applications, London: Institute of Physics Publishing, 2004.
[3]* R. Anderson, “3 Axis CNC Router,” Instructables, [online] (Accessed: 15 November
2013).
[4] J. Matsubara and G. Celani, “Origami: symmetry and applications in architecture,” (JM
Matsubara), [online] 2006, (Accessed: 14 November 2013).
[5] “Sheet metal laser cutter,” Kern Laser Systems, [online], (Accessed: 14 November 2013).
[6] E. Standley, “Laser Cut Paper Stained Glass Windows,” Pokono, [online] 16 January
2013, (Accessed: 15 November 2013).
[7] S. Mueller, B. Kruck, and P. Baudisch, “LaserOrigami: Laser-Cutting 3D Objects,” CHI,
2013
(*adapted )