3-d printed combat aircraft
DESCRIPTION
3-d printing of combat aircraft using stlTRANSCRIPT
FIRST COMBAT AIRCRAFT
WITH 3-D PRINTED PARTS
SELF STUDY 1st PHASE OF
EVALUATION REPORT
Sanjay Vinayak H.K
2nd semester ’F’ section, USN: 1RV13CS139
Computer Science Engineering
R.V. College of Engineering, Bangalore
Abstract-This document gives the brief report of the various schemes and techniques used in the development and manufacturing of 3-
D printed parts of a combat aircraft. This topic has been split into four different components namely Mathematics, Mechanical
Engineering, Electronics and Communication Engineering and Computer Science Engineering.
TABLE OF CONTENTS
INTRODUCTION TO 3-D PRINTING
FIRST COMBAT AIRCRAFT WITH 3-D PRINTED PARTS
MATHEMATICS COMPONENT
MECHANICAL ENGINEERING COMPONENT
ELECTRONICS AND COMMUNICATION ENGINEERING COMPONENT
COMPUTER SCIENCE ENGINEERING COMPONENT
ACKNOWLEDGEMENT
REFERENCES
I. INTRODUCTION TO 3-D PRINTING
Additive manufacturing or 3D printing is a process of making three dimensional solid objects from a digital
model. 3D printing is achieved using additive processes, where an object is created by laying down
successive layers of material. 3D printing is considered distinct from traditional machining techniques
(subtractive processes) which mostly rely on the removal of material by drilling, cutting etc.
Fig1. Stereolithographic apparatus (Type of Additive manufacturing)
3D printing is usually performed by a materials printer using digital technology. It is a rapid prototyping and
rapid manufacturing technology.
The technology is used in the fields of jewellery, footwear, industrial design, architecture, engineering and
construction (AEC), automotive, aerospace, dental and medical industries, education, geographic
information systems, civil engineering, and many others.
II. FIRST COMBAT AIRCRAFT WITH 3-D
PRINTED PARTS
Fig2.Tornado aircraft fitted with 3-d printed parts
BAE Systems plc, a British multinational defence, security and aerospace company has developed an aircraft
with 3-D printed parts for the Royal air force. The Panavia Tornado is a multirole, twin-engined aircraft
designed to excel at low-level penetration of enemy defences. Variable wing geometry, allowing for minimal
drag during the critical low-level dash towards a well-prepared enemy, had been desired from the project's
start. Advanced navigation and flight computers, including the then-innovative fly-by-wire system, greatly
reduced the workload of the pilot during low-level flight and eased control of the aircraft. For long range
bombing missions, the Tornado has a retractable refuelling probe .
The Tornado GR4 aircraft of the Royal Air Force has been fitted with 3-D printed components which
include protective covers for cockpit radios, support struts on the air intake door and protective guards for
power take-off shafts. BAE Systems is no stranger to 3D printing. It's been using and developing
stereolithography (SLA) internally for more than 15 years, for both rapid prototyping and development
tooling. "The knowledge and experience gained in SLA is now being adapted to support the emerging
additive manufacturing technologies with the aim of producing quicker and cheaper flying parts
III. MATHEMATICS COMPONENT
For every 3-D printed object, mathematical models have to be developed which are then converted to the
computer models.Using the computer model, the printer prints the required 3-D object.
Mathematical concept computer model 3D printed object
INTRODUCTION TO 3 DIMENSIONS:
Three-dimensional space is a geometric 3-parameters model of the physical universe (without considering
time) in which all known matter exists. These three dimensions can be labelled by a combination of three
chosen from the terms length, width, height, depth, and breadth. In mathematics, analytic geometry (also
called Cartesian geometry) describes every point in three-dimensional space by means of three coordinates.
Three coordinate axes are given, usually each perpendicular to the other two at the origin, the point at which
they cross. They are usually labelled x, y, and z. Relative to these axes, the position of any point in three-
dimensional space is given by an ordered triple of real numbers, each number giving the distance of that
point from the origin measured along the given axis, which is equal to the distance of that point from the
plane determined by the other two axes.
Other popular methods of describing the location of a point in three-dimensional space include cylindrical
coordinates and spherical coordinates, though there is an infinite number of possible methods. Another
mathematical way of viewing three-dimensional space is found in linear algebra, where the idea of
independence is crucial. Space has three dimensions because the length of a box is independent of its width
or breadth. In the technical language of linear algebra, space is three-dimensional because every point in
space can be described by a linear combination of three independent vectors. In this view, space-time is
four-dimensional because the location of a point in time is independent of its location in space.
The visual ability to perceive the world in three dimensions is called perception. With the space , the
topologists locally model all other 3-manifolds.Complex shapes like hyperbolic paraboloid, penrose triangle
can easily be printed using 3-D printers
Hyperbolic paraboloid : The hyperbolic paraboloid is a doubly ruled surface shaped like a saddle.
In a suitable coordinate system, a hyperbolic paraboloid can be represented by the equation in cartesian co-
ordinates as:
Fig3. 3-d model of a hyperbolic paraboloid
(courtesy: www.shapeways.com)
Penrose triangle: The Penrose triangle, also known as the Penrose tribar, is an impossible object or
an optical illusion. The tribar appears to be a solid object, made of three straight beams of square
cross-section which meet pairwise at right angles at the vertices of the triangle they form. This
combination of properties cannot be realized by any 3-dimensional object in ordinary Euclidean
space. Such an object can exist in certain Euclidean 3-manifolds. There also exist 3-dimensional
solid shapes each of which, when viewed from a certain angle, appears the same as the 2-dimensional
depiction of the Penrose triangle on this page. The term "Penrose triangle" can refer to the 2-
dimensional depiction or the impossible object itself.
The penrose triangle has been successfully printed using a 3-d printer as shown:
Fig4. 3-d printed penrose triangle
(courtesy: numbersixreprap.blogspot.com)
IV. MECHANICAL ENGINEERING COMPONENT
The different additive manufacturing methods used today are:
STEREOLITHOGRAPHY (SLA):
A SLA 3D printer works by concentrating a beam of ultraviolet light focused onto the surface of a
vat filled with liquid photocurable resin. The UV laser beam draws out the 3D model one thin layer
at a time, hardening that “slice” of the eventual 3D model as the light hits the resin. Slice after slice
is created, with each one bonded to the other, and next thing you know you have a full, extremely
high-resolution three dimensional model lifted out of the vat. Unused resin is reusable for the next
job.
FUSED DEPOSITION MODELLING (FDM):
In FDM, the object is produced by extruding a stream of melted thermoplastic material to form
layers. Each layer stacks on top of and fuses with the previous layer as the material hardens almost
immediately after leaving the extrusion nozzle. It is one of the less expensive 3D printing methods.
Most FDM printers print with ABS plastic (think Lego), as well as PLA (Polylactic acid), a
biodegradable polymer, which is produced from organic material
SELECTIVE LASER SINTERING (SLS):
SLS works similarly to SLA, but instead of liquid photopolymer in a vat, you’ll find powdered
materials, such as polystyrene, ceramics, glass, nylon, and metals including steel, titanium,
aluminium, and silver. When the laser hits the powder, the powder is fused at that point (sintered).
All unsintered powder remains as is, and becomes a support structure for the object. The lack of
necessity for any support structure with SLS is an advantage over FDM/FFF and SLA — there’s
none to remove after the model is complete, and no extra waste was created. All unused powder can
be used for the next printing.
SELECTIVE LASER MELTING:
With SLM thin layers of atomized fine metal powder are evenly distributed using a coating
mechanism onto a substrate plate, usually metal, that is fastened to an indexing table that moves in
the vertical (Z) axis. This takes place inside a chamber containing a tightly controlled atmosphere of
inert gas, either argon or nitrogen at oxygen levels below 500 parts per million. Once each layer has
been distributed each 2D slice of the part geometry is fused by selectively applying the laser energy
to the powder surface, by directing the focused laser beam using two high frequency scanning mirrors
in the X and Y axes. The laser energy is intense enough to permit full melting (welding) of the
particles to form solid metal. The process is repeated layer after layer until the part is complete.
The 3-D printed parts used in the Tornado GR4 are:
POWER TAKEOFF SHAFT GUARD:
A power take-off or power take off (PTO) is any of several methods for taking power from a power source,
such as a running engine, and transmitting it to an application such as an attached implement or separate
machines. A guard covers the shaft to prevent injuries during maintenance called the PTO shaft guard.
Fig5. A PTO shaft covered by a guard
(Courtesy: www.adlib.everysite.co.uk)
METAL BRACKET FOR CAMERA MOUNTING:
The Tornado’s camera bracket was manufactured using Selective Laser Melting Technique.
Fig6. Support struts for landing gears are seen attached sideways
(Courtesy:BAE systems)
All the metal parts on the RAF’s Tornado have been printed using stainless steel and all the non metallic
parts using acrylonitrile butadiene styrene (ABS) which is a thermoplastic.
V. ELECTRONICS AND COMMUNICATION ENGINEERING
COMPONENT
Fig7. Block Diagram of a 3-D printer
(Courtesy:www.ti.com)
3-D Printer process successive layers of material to produce a 3-D physical objects. The object is specified
by a 3D Computer Aided Design (CAD) model. 3D printer software transforms the virtual 3D model into a
series of layers suitable for printing the object.
It is often used to quickly create detailed prototypes. With this technology, printing parts of a material can
be done in a single process flow. 3D printers are becoming more affordable for medium and small scale
businesses in which rapid prototyping is brought all the way into the office, no longer requiring
manufacturing floor space.
Two common methods for 3D printing are digital exposure and laser sintering. The high level principles for
incorporating DLP technology into a 3D printing solution can be applied to both methods, but digital
exposure is represented in the system block diagram.
For the digital exposure technique, the 3D object is constructed by laying down successive thin horizontal
cross-sections or layers of an ultraviolet (UV) curable liquid photopolymer resin. For each layer, the UV
light image from the DLP Digital Micro mirror Device (DMD) creates a pattern which hardens the polymer
resin where it is exposed to the light.
The cross-section pattern is produced by the individual mirrors that correspond to each pixel on the current
layer. This pattern projects through an imaging lens onto the surface of the UV curable liquid photopolymer
resin, curing or hardening it where the pixels are on. As depicted in the diagram, one resin is the build
material and the second is material to support overhanging features and thin vertical walls during
construction. The support material is later removed by heat or dissolved with a solvent or water.
These layers fuse automatically and the process repeats one layer at a time until the model is built. Cure
rates are possible under 0.2 seconds per layer. Layer thickness typically ranges from 1um to 250um based
upon the resin and wavelength of the UV light used. More detailed images require more discrete cross-
sections to assume the continuous smooth surface effect of the resulting object.
The diagram shows a DLP chipset, which includes the DMD, and a DMD Controller chip, plus a DMD
Analog Control chip (depending on the specific DLP chipset). DLP chipsets are available with different
DMD sizes, pixel pitches, resolutions, and other specifications. DLP also offers devices targeted for use
with UV light. The best choice for a DLP chipset may depend on the desired object feature size, patterning
speed and necessary wavelengths to cure the resin.
The CAD model is produced by software running on a PC. The system control and signal processing is
accomplished by the Embedded Processor . The details of the optical layout and components are not shown
in the diagram. The diagram is intended to convey as simply as possible the overall functionality of a DLP-
based 3D Printer application.
VI. COMPUTER SCIENCE ENGINEERING COMPONENT
Fig8 . Flowchart of 3-D printing processes
(Courtesy: www.emeraldinsight.com)
Some of the 3-D printing software in use today are:
1. Google SketchUp 6. BRL-CAD
2. 3DCrafter 7. Blender
3. FreeCAD 8. AutoCAD
4. LeoCAD 9. Rhino3D
5. OpenSCAD 10. Solidworks
In the 2D world, a sheet of printed paper output from a printer was “designed” on the computer in a program
such as Microsoft Word. The file — the Word document — contains the instructions that tell the printer
what to do.
In the 3D world, a 3D printer also needs to have instructions for what to print. It needs a file as well. The
file — a Computer Aided Design (CAD) file — is created with the use of a 3D modeling program, either
from scratch or beginning with a 3D model created by a 3D scanner. Either way, the program creates a file
that is sent to the 3D printer. Along the way, software slices the design into hundreds, or more likely
thousands, of horizontal layers. These layers will be printed one atop the other until the 3D object is done.
Fig8. CAD design for 3-D printing of the parts of the Tornado aircraft
(Courtesy: BAE systems)
ACKNOWLEDGEMENT
I thank my teachers for providing me the opportunity to
learn about 3-D printing and its applications. I could learn a
lot about the topic and it has helped me in the overall
understanding of the topic under different subjects.
References
[1] www.baessytems.com/article/BAES_164442/3d-
printed-metal-part-flown-for-first-time-on-uk-fighter-jet
[2] www.custompart.net
[3] www.emeraldinsight.com
[4] ‘3-D printing for mathematical visualisation’ by Henry
Segerman, http://link.springer.com/article/10.1007/s00283-012-
9319-7
[5] ‘Thinking like Archimedes with a 3-D printer’ by
Oliver Knill and Elizabeth Slavkovsky