Origami Metal Sculpture by Bruce Keller

Bruce A Keller's

http://en.wikipedia.org/wiki/Origami


Origami
From Wikipedia, the free encyclopedia

The folding of an Origami crane

Origami (from ori meaning "folding", and kami meaning "paper"; kami
changes to gami due to rendaku) is the traditional Japanese art of
paper folding, which started in the 17th century AD at the latest and
was popularized outside of Japan in the mid-1900s. It has since then
evolved into a modern art form. The goal of this art is to transform
a flat sheet of material into a finished sculpture through folding
and sculpting techniques, and as such the use of cuts or glue are not
considered to be origami. Paper cutting and gluing is usually
considered kirigami.

The number of basic origami folds is small, but they can be combined
in a variety of ways to make intricate designs. The best known
origami model is probably the Japanese paper crane. In general, these
designs begin with a square sheet of paper whose sides may be
different colors or prints. Traditional Japanese origami, which has
been practiced since the Edo era (1603-1867), has often been less
strict about these conventions, sometimes cutting the paper or using
nonsquare shapes to start with.

The principles of origami are also being used in stents, packaging
and other engineering structures.

History Main article: History of origami Swan by Akira Yoshizawa, the
father of modern origami techniques.  Japanese school children
dedicate their contribution of Thousand origami cranes at the Sadako
Sasaki memorial in Hiroshima.

There is much speculation about the origin of Origami. While Japan
seems to have had the most extensive tradition, there is evidence of
an independent tradition of paperfolding in China, as well as in
Germany, Italy and Spain among other places. However, because of the
problems associated with preserving origami, there is very little
direct evidence of its age or origins, aside from references in
published material.

In China, traditional funerals include burning folded paper, most
often representations of gold nuggets (yuanbao). It is not known when
this practice started, but it seems to have become popular during the
Sung Dynasty (905-1125 CE).[2] The paper folding has typically been
of objects like dishes, hats or boats rather than animals or
flowers.[3]

The earliest evidence of paperfolding in Europe is a picture of a
small paper boat in Tractatus de sphaera mundi from 1490. There is
also evidence of a cut and folded paper box from 1440.[4] It is
probable paperfolding in the west originated with the Moors much
earlier,[5] it is not known if it was independently discovered or
knowledge of origami came along the silk route.

In Japan, the earliest unambiguous reference to a paper model is in a
short poem by Ihara Saikaku in 1680 which describes paper butterflies
in a dream.[6] Origami butterflies were used during the celebration
of Shinto weddings to represent the bride and groom, so paperfolding
had already become a significant aspect of Japanese ceremony by the
Heian period (794-1185) of Japanese history, enough that the
reference in this poem would be recognized. Samurai warriors would
exchange gifts adorned with noshi, a sort of good luck token made of
folded strips of paper.

In the early 1900s, Akira Yoshizawa, Kosho Uchiyama, and others began
creating and recording original origami works. Akira Yoshizawa in
particular was responsible for a number of innovations, such as
wet-folding and the Yoshizawa-Randlett diagramming system, and his
work inspired a renaissance of the art form.[7] During the 1980s a
number of folders started systematically studying the mathematical
properties of folded forms, which led to a steady increase in the
complexity of origami models, which continued well into the 1990s,
after which some designers started returning to simpler forms.[8]
[edit] Techniques and materials [edit] Techniques Main article:
Yoshizawa-Randlett system

Many origami books begin with a description of basic origami
techniques which are used to construct the models. These include
simple diagrams of basic folds like valley and mountain folds,
pleats, reverse folds, squash folds, and sinks. There are also
standard named bases which are used in a wide variety of models, for
instance the bird base is an intermediate stage in the construction
of the flapping bird.[9] [edit] Origami paper Main article: Origami
paper crane and papers of the same size used to fold it

Almost any laminar material can be used for folding; the only
requirement is that it should hold a crease.

Origami paper, often referred to as "kami" (Japanese for paper), is
sold in prepackaged squares of various sizes ranging from 2.5 cm to
25 cm or more. It is commonly colored on one side and white on the
other; however, dual coloured and patterned versions exist and can be
used effectively for color-changed models. Origami paper weighs
slightly less than copy paper, making it suitable for a wider range
of models.

Normal copy paper with weights of 70-90 g/m2 can be used for simple
folds, such as the crane and waterbomb. Heavier weight papers of
(19-24&nb 100 g/m2 (approx. 25 lb) or more can be wet-folded. This
technique allows for a more rounded sculpting of the model, which
becomes rigid and sturdy when it is dry.

Foil-backed paper, just as its name implies, is a sheet of thin foil
glued to a sheet of thin paper. Related to this is tissue foil, which
is made by gluing a thin piece of tissue paper to kitchen aluminium
foil. A second piece of tissue can be glued onto the reverse side to
produce a tissue/foil/tissue sandwich. Foil-backed paper is available
commercially, but not tissue foil; it must be handmade. Both types of
foil materials are suitable for complex models.

Washi is the traditional origami paper used in Japan. Washi is
generally tougher than ordinary paper made from wood pulp, and is
used in many traditional arts. Washi is commonly made using fibres
from the bark of the gampi tree, the mitsumata shrub (Edgeworthia
papyrifera), or the paper mulberry but also can be made using bamboo,
hemp, rice, and wheat.

Artisan papers such as unryu, lokta, hanji, gampi, kozo, saa, and
abaca have long fibres and are often extremely strong. As these
papers are floppy to start with, they are often backcoated or resized
with methylcellulose or wheat paste before folding. Also, these
papers are extremely thin and compressible, allowing for thin,
narrowed limbs as in the case of insect models.

Paper money from various countries is also popular to create origami
with; this is known variously as Dollar Origami, Orikane, and Money
Origami.

Tools It is common to fold using a flat surface but some folders like
doing it in the air with no tools especially when displaying the
folding. Many folders believe no tool should be used when folding.
However a couple of tools can help especially with the more complex
models. For instance a bone folder allows sharp creases to be made in
the paper easily, paper clips can act as extra pairs of fingers, and
tweezers can be used to make small folds. When making complex models
from origami crease patterns, it can help to use a ruler and
ballpoint embosser to score the creases. Completed models can be
sprayed so they keep their shape better, and of course a spray is
needed when wet folding.

Types of origami

Action origami Origami not only covers still-life, there are also
moving objects; Origami can move in clever ways. Action origami
includes origami that flies, requires inflation to complete, or, when
complete, uses the kinetic energy of a person's hands, applied at a
certain region on the model, to move another flap or limb. Some argue
that, strictly speaking, only the latter is really "recognized" as
action origami. Action origami, first appearing with the traditional
Japanese flapping bird, is quite common. One example is Robert Lang's
instrumentalists; when the figures' heads are pulled away from their
bodies, their hands will move, resembling the playing of music.
[edit] Modular origami A stellated icosahedron made from custom
papers


Modular origami consists of putting a number of similar pieces
together to form a complete model. Normally the individual pieces are
simple but the final assembly may be tricky.  Many of the modular
origami models are decorative balls like kusudama, the technique
differs though in that kusudama allows the pieces to be put together
using thread or glue.

Chinese paper folding includes a style called 3D origami where large
numbers of pieces are put together to make elaborate models.
Sometimes paper money is used for the modules. This style originated
from some Chinese refugees while they were detained in America and is
also called Golden Venture folding from the ship they came on.

Wet-folding is an origami technique for producing models with gentle
curves rather than geometric straight folds and flat surfaces. The
paper is dampened so it can be moulded easily, the final model keeps
its shape when it dries. It can be used, for instance, to produce
very natural looking animal models. Size, an adhesive that is crisp
and hard when dry, but dissolves in water when wet and becoming soft
and flexible, is often applied to the paper either at the pulp stage
while the paper is being formed, or on the surface of a ready sheet
of paper. The latter method is called external sizing and most
commonly uses Methylcellulose, or MC, paste, or various plant
starches.

Pureland origami is origami with the restriction that only one fold
may be done at a time, more complex folds like reverse folds are not
allowed, and all folds have straightforward locations. It was
developed by John Smith in the 1970s to help inexperienced folders or
those with limited motor skills. Some designers also like the
challenge of creating good models within the very strict constraints.

Origami Tessellations This branch of origami is one that has grown in
popularity recently. Tessellation refers to a collection of figures
fill a plane with no gaps or overlaps. In origami tessellations,
pleats are used to connect molecules such as twist folds together in
a repeating fashion.

During the 1960s, Shuzo Fujimoto was the first to explore twist fold
tessellations in any systematic way, coming up with dozens of
patterns and establishing the genre in the origami mainstream. Around
the same time period, Ron Resch patented some tessellation patterns
as part of his explorations into kinetic sculpture and developable
surfaces, although his work was not known by the origami community
until the 1980s. Chris Palmer is an artist who has extensively
explored tessellations after seeing the Zilij patterns in the
Alhambra, and has found ways to create detailed origami tessellations
out of silk. Robert Lang and Alex Bateman are two designers who use
computer programs to create origami tessellations. The first American
book on origami tessellations was just published by Eric Gjerde and
the field has been expanding rapidly. There are numerous origami
tessellation artists including Chris Palmer (U.S.), Eric Gjerde
(U.S.), Polly Verity (Scotland), Joel Cooper (U.S.), Christine Edison
(U.S.), Ray Schamp (U.S.), Roberto Gretter (Italy), Goran Konjevod
(U.S.),and Christiane Bettens (Switzerland) that are showing works
that are both geometric and representational.  [edit] Kirigami Main
article: Kirigami

Kirigami is a Japanese term for paper cutting. Cutting was often used
in traditional Japanese origami, but modern innovations in technique
have made the use of cuts unnecessary. Most origami designers no
longer consider models with cuts to be origami, instead using the
term Kirigami to describe them. This change in attitude occurred
during the 1960s and 70s, so early origami books often use cuts, but
for the most part they have disappeared from the modern origami
repertoire; most modern books don't even mention cutting.

Technical origami, also known as origami sekkei, is a field of
origami that has developed almost hand-in-hand with the field of
mathematical origami. In the early days of origami, development of
new designs was largely a mix of trial-and-error, luck and
serendipity. With advances in origami mathematics however, the basic
structure of a new origami model can be theoretically plotted out on
paper before any actual folding even occurs. This method of origami
design was developed by Robert Lang, Meguro Toshiyuki and others, and
allows for the creation of extremely complex multi-limbed models such
as many-legged centipedes, human figures with a full complement of
fingers and toes, and the like.

The main starting point for such technical designs is the crease
pattern (often abbreviated as CP), which is essentially the layout of
the creases required to form the final model. Although not intended
as a substitute for diagrams, folding from crease patterns is
starting to gain in popularity, partly because of the challenge of
being able to 'crack' the pattern, and also partly because the crease
pattern is often the only resource available to fold a given model,
should the designer choose not to produce diagrams. Still, there are
many cases in which designers wish to sequence the steps of their
models but lack the means to design clear diagrams. Such origamists
occasionally resort to the Sequenced Crease Pattern (abbreviated as
SCP) which is a set of crease patterns showing the creases up to each
respective fold. The SCP eliminates the need for diagramming programs
or artistic ability while maintaining the step-by-step process for
other folders to see. Another name for the Sequenced Crease Pattern
is the Progressive Crease Pattern (PCP).

Paradoxically enough, when origami designers come up with a crease
pattern for a new design, the majority of the smaller creases are
relatively unimportant and added only towards the completion of the
crease pattern. What is more important is the allocation of regions
of the paper and how these are mapped to the structure of the object
being designed. For a specific class of origami bases known as
'uniaxial bases', the pattern of allocations is referred to as the
'circle-packing'. Using optimization algorithms, a circle-packing
figure can be computed for any uniaxial base of arbitrary complexity.
Once this figure is computed, the creases which are then used to
obtain the base structure can be added. This is not a unique
mathematical process, hence it is possible for two designs to have
the same circle-packing, and yet different crease pattern structures.

As a circle encloses the minimum amount of area for a given
perimeter, circle packing allows for maximum efficiency in terms of
paper usage. However, other polygonal shapes can be used to solve the
packing problem as well. The use of polygonal shapes other than
circles is often motivated by the desire to find easily locatable
creases (such as multiples of 22.5 degrees) and hence an easier
folding sequence as well. One popular offshoot of the circle packing
method is box-pleating, where squares are used instead of circles. As
a result, the crease pattern that arises from this method contains
only 45 and 90 degree angles, which makes for easier folding.

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http://en.wikipedia.org/wiki/Welding


Weling Processes

One of the most common types of arc welding is shielded metal arc
welding (SMAW);[19] it is also known as manual metal arc welding
(MMA) or stick welding. Electric current is used to strike an arc
between the base material and consumable electrode rod, which is made
of steel and is covered with a flux that protects the weld area from
oxidation and contamination by producing carbon dioxide (CO2) gas
during the welding process. The electrode core itself acts as filler
material, making a separate filler unnecessary.[19] Shielded metal
arc welding

The process is versatile and can be performed with relatively
inexpensive equipment, making it well suited to shop jobs and field
work.[19][20] An operator can become reasonably proficient with a
modest amount of training and can achieve mastery with experience.
Weld times are rather slow, since the consumable electrodes must be
frequently replaced and because slag, the residue from the flux, must
be chipped away after welding.[19] Furthermore, the process is
generally limited to welding ferrous materials, though special
electrodes have made possible the welding of cast iron, nickel,
aluminum, copper, and other metals.[20]

Gas metal arc welding (GMAW), also known as metal inert gas or MIG
welding, is a semi-automatic or automatic process that uses a
continuous wire feed as an electrode and an inert or semi-inert gas
mixture to protect the weld from contamination. Since the electrode
is continuous, welding speeds are greater for GMAW than for SMAW.[21]

A related process, flux-cored arc welding (FCAW), uses similar
equipment but uses wire consisting of a steel electrode surrounding a
powder fill material. This cored wire is more expensive than the
standard solid wire and can generate fumes and/or slag, but it
permits even higher welding speed and greater metal penetration.[22]

Gas tungsten arc welding (GTAW), or tungsten inert gas (TIG) welding,
is a manual welding process that uses a nonconsumable tungsten
electrode, an inert or semi-inert gas mixture, and a separate filler
material.[23] Especially useful for welding thin materials, this
method is characterized by a stable arc and high quality welds, but
it requires significant operator skill and can only be accomplished
at relatively low speeds.[23]

GTAW can be used on nearly all weldable metals, though it is most
often applied to stainless steel and light metals. It is often used
when quality welds are extremely important, such as in bicycle,
aircraft and naval applications.[23] A related process, plasma arc
welding, also uses a tungsten electrode but uses plasma gas to make
the arc. The arc is more concentrated than the GTAW arc, making
transverse control more critical and thus generally restricting the
technique to a mechanized process. Because of its stable current, the
method can be used on a wider range of material thicknesses than can
the GTAW process and it is much faster. It can be applied to all of
the same materials as GTAW except magnesium, and automated welding of
stainless steel is one important application of the process. A
variation of the process is plasma cutting, an efficient steel
cutting process.[24]

Submerged arc welding (SAW) is a high-productivity welding method in
which the arc is struck beneath a covering layer of flux. This
increases arc quality, since contaminants in the atmosphere are
blocked by the flux. The slag that forms on the weld generally comes
off by itself, and combined with the use of a continuous wire feed,
the weld deposition rate is high. Working conditions are much
improved over other arc welding processes, since the flux hides the
arc and almost no smoke is produced. The process is commonly used in
industry, especially for large products and in the manufacture of
welded pressure vessels.[25] Other arc welding processes include
atomic hydrogen welding, electroslag welding, electrogas welding, and
stud arc welding.[26]

Cranes by the Little Pond			Traditional Crane on the Deck
Swan set at Sunrise			Traditional Crane
Cranes in the yard			Standing Cranes