3. STL
STL is also known as Standard Tessellation Language. This file format is
supported by many other software packages. It is widely used for rapid
prototyping and computer aided manufacturing. The STL format
specifies both ASCII and binary representations. Binary files are more
common, since they are more compact.
An STL file describes a raw unstructured triangulated surface by the
unit normal and vertices of the triangles using a three-dimensional
Carteisan coordinate system . STL coordinates must be positive
numbers, there is no scale information, and the units are arbitrary.
Rhinoceros (abbreviated Rhino) is a stand-alone, commercial 3D
modeling software application developed by Robert McNeel &
Associates. The software is based on a mathematical model called
NURBS (non uniform rational B-spline ), which is adept at
producing curves and surfaces in computer graphics.
Non-uniform rational basis spline (NURBS) is a mathematical
model commonly used in computer graphics for generating and
representing curves and surfaces. It offers great flexibility and
precision for handling both analytic and modelated shapes.
Rhinoceros 3D
4. This is an algorithm for a typical STL program
The coloring option is
not provided in the basic STL
header file. STL allows the programmer to
choose different shades of the three basic
colors –red , green and blue by changing the
number associated with each color within the
range
Grasshopper 3D
Grasshopper is a visual programming language
developed by David Rutten at Robert McNeel &
Associates. Grasshopper runs within the
Rhinoceros CAD application. Programs are
created by dragging components onto a canvas.
The outputs to these components are then
connected to the inputs of subsequent
components. Grasshopper is used mainly to build
generative algorithms. Many of Grasshopper's
components create 3D geometry. Programs may
also contain other types of algorithms including
numeric, textual,audio-visual and hepatic
applications.
A user requires
absolutely no
knowledge of
programming to
make designs
using
Grasshopper.
6. • PA12 or Nylon 12
1. Flexible material. Hence can be used to
make springs that allow bending of fabrics
2. Used to make rigid support fabrics
• Cosyflex
Resembles knitted fabrics. Used for making
hygiene textiles.
1. High elasticity
2. Waterproof and breathable
3. Made of rubber latex and viscose fibres
4. Fully biodegradable
• TPU 92A (Thermoplastic
Polyurethane)
1. Developed specifically for textile
3D printing
2. Durable elasticity
3. High tear resistance
4. High resistance to load
5. Good temperature range
MATERIALS
7. Mechanical Processes
Selective Laser Sintering (SLS)
The machine uses a computer-controlled laser to draw the bottom cross section onto the
surface of a bed coated with a powdered polymer that melts and fuses where struck by the
laser.
It consists of two pistons and a roller. The build piston
moves upwards and the roller pushes the polymeric
powder onto the build piston.
The build piston is then lowered to a depth corresponding
to the section's thickness. The feed piston moves up again
and the roller pushes some more material. And the next
cross section is then drawn directly on top of the previous
one. This is repeated until the part is finished.
There are two techniques used
-Selective laser sintering
-Fusion deposition modeling
Fusion Deposition Modeling (FDM)
The FDM technology works using a plastic filament or metal wire
which is unwound from a coil and supplies material to an heated
extrusion nozzle which can move in all directions.
The molten polymeric material is dropped in the form of beads. It
instantly solidifies when it exits nozzle forming one layer.
10. Electronics Component
Lasers
A laser oscillator comprises of an optical resonator in which light can circulate
e.g. between two mirrors. Within the resonator is a gain medium which
amplifies the light. Without the gain medium, the circulating light would
become weaker and weaker in each resonator round trip, because it
experiences losses upon reflection at mirrors. To amplify light, the gain
medium requires external supply of energy – it needs to be “pumped”, e.g. by
injecting an electric current.
11. Electronics Component
1. CO2 lasers
Continuous wave diode i.e. output power is
constant over time.
Lasing medium is a mixture of CO2, nitrogen,
hydrogen and helium.
Excited nitrogen molecules collide with C02
molecules. Thus excited CO2 molecules
release photons.
Thus population inversion is caused due to
collision due to nitrogen molecules. Helium
helps in removing heat.
Infra-red light produced.
P-n junction or p-i-n junction
acts as lasing medium.
Similar to an LED where
recombination of holes and
electrons produces photons.
Photon emission can be
stimulated and hence
amplification can be achieved.
2.Laser diodes
12. Electronics Component
• Heating elements
1. Power resistors
2. Ceramic heating cartridge – joule heating element consisting of nichrome wire
wound on a ceramic core.
3. Power MOSFET –metal–oxide–semiconductor field-effect transistor used in linear
region/ ohmic region. Used instead of BJT as they do not suffer from thermal
runaway. Ohmic mode is achieved when VGS > Vth and VDS < ( VGS – Vth )
Diagrammatic representation of mosfetCeramic heating cartridgePower resistor
14. Mathematics Component
Math plays an important role in designing 3D printed textiles. Of course the final
modeling is done using software on computers but the basic principle involved is
derived from mathematics.
Coordinate Systems
-A coordinate is a series of numbers that describes the location in the given space.
-3D graphics system operates in a mathematical space. The space used in most of
the 3D graphics is called 3D Cartesian coordinate.
-The Cartesian coordinate system uses a series of intersecting line segments to
describe a location with respect to the origin.
15. Constructive Solid Geometry
Simple solid objects used for representation are called primitives. They can be cubes,
cuboids, cones, spheres, cylinders, etc.
A complex object can be constructed from primitives by means of operations, which
are typically Boolean operations on sets i.e. union, intersection and difference.
Union Difference Intersection
16. Scaling
An object can be scaled to make it proportionally bigger or smaller by a factor of k. If the
same scale is applied in all the directions, then the scaling is being performed in a
uniform scale. Thus, the object is dilated about the origin. Uniform scaling preserves the
angles and proportions. If all the lengths in uniform scaling increase or decrease by a
factor of k, then the areas change by a factor of k^2and the volumes (in 3D) by a factor
of k^3.
17. Bibliography
• Silicon graphics international corp. (SGI) official website
• Blogs by Solid Concepts®
• www.3ders.org
• www.thre3d.com
• www.tamicare.com
