1. INTRODUCTION

3 Dimensions printing is a method of converting a virtual 3D model into a physical object. 3D printing is a category of rapid prototyping technology. 3D printers typically work by printing successive layers on top of the previous to build up a three dimensional object.

The past decade has witnessed the emergence of new manufacturing technologies that build parts on a layer-by-layer basis. Using these technologies, manufacturing time for parts of virtually any complexity is reduced considerably. In other words, it is rapid. Rapid Prototyping Technologies and Rapid Manufacturing offer great potential for producing models and unique parts for manufacturing industry.

A few years ago, to get some prototyping work done for a product or design you are working on, you are required to spend a lot of man-hours just to come up with the model. Those hours will be spent creating miniature parts of your design using wood and then gluing all those parts together painstakingly. Prototyping is, at the very least, time-consuming and extremely tedious.

These days, however, you can take the tediousness and the time investment out of your prototyping tasks through rapid prototyping or 3d printing. 3D printing is a revolutionary method for creating 3D models with the use of inkjet technology. Many engineers have even dubbed 3D printing as the process of creating something out of nothing. Thus, the reliability of products can be increased; investment of time and money is less risky. Not everything that is thinkable today is already workable or available at a reasonable price, but this technology is fast evolving and the better the challenges, the better for this developing process.

The term Rapid prototyping (RP) refers to a class of technologies that can automatically construct physical models from Computer-Aided Design (CAD) data.

It is a free form fabrication technique by which a total object of prescribed shape, dimension and finish can be directly generated from the CAD based geometrical model stored in a computer, with little human intervention. Rapid prototyping is an "additive" process, combining layers of paper, wax, or plastic to create a solid object. In contrast, most machining processes (milling, drilling, grinding, etc.) are "subtractive" processes that remove material from a solid block. RP’s additive nature allows it to create objects with complicated internal features that cannot be manufactured by other means.

In addition to prototypes, RP techniques can also be used to make tooling (referred to as rapid tooling) and even production-quality parts (rapid manufacturing). For small production runs and complicated objects, rapid prototyping is often the best manufacturing process available. Of course, "rapid" is a relative term. Most prototypes require from three to seventy-two hours to build, depending on the size and complexity of the object. This may seem slow, but it is much faster than the weeks or months required to make a prototype by traditional means such as machining. These dramatic time savings allow manufacturers to bring products to market faster and more cheaply.

LITERATURE REVIEW

2.1 3D printing: making the digital real

Imagine a future in which a device connected to a computer can print a solid object. A future in which we can have tangible goods as well as intangible services delivered to our desktops or high street shops over the Internet. And a future in which the everyday "atomization" of virtual objects into hard reality has turned the mass pre-production and stock-holding of a wide range of goods and spare parts into no more than an historical legacy.

Such a future may sound like it is being plucked from the worlds of Star Trek. However, whilst transporter devices that can instantaneously deliver us to remote locations may remain a fantasy, 3D printers capable of outputting physical objects have been in development for over two decades. What's more, several 3D printers are already on the market. Available from companies including Fortus, 3D Systems, Solid Scape, ZCorp, and Desktop Factory, these amazing devices produce solid, 3D objects from computer data in roughly the same way that 2D printers take our digital images and output hardcopy photos.

The Desktop Factory currently sells a 3D printer for Rupees 45000. This can print models up to a five-inch cube in size with consumables costing around Rupees1 per cubic inch. However, prices for most 3D printers tend to start in the ten-to-twenty thousand Rupees bracket and spiral upwards. Although some desktop models are on the market, most 3D printers are usually fairly bulky and often floor-standing.

2.2 Rapid Prototyping Techniques

Rapid prototyping is the fabrication of parts from CAD data sources. Several rapid prototyping methods have been created to produce objects of complex geometries in a relatively short amount of time. These systems are beneficial to engineers by allowing them to better understand the products that they are designing and by providing them with a way to create a visual aid to communicate with others. Rapid prototyping allows design challenges to be determined earlier in the design process, saving time and money. The technology of rapid prototyping is easy to access and simple to understand.

2.2.1 Stereo lithography

Patented in 1986, stereolithography started the rapid prototyping revolution. The technique builds three-dimensional models from liquid photosensitive polymers that solidify when exposed to ultraviolet light. As shown in the figure below, the model is built upon a platform situated just below the surface in a vat of liquid epoxy or acrylate resin. A low-power highly focused UV laser traces out the first layer, solidifying the model’s cross section while leaving excess areas liquid. Next, an elevator incrementally lowers the platform into the liquid polymer. A sweeper re-coats the solidified layer with liquid, and the laser traces the second layer atop the first. This process is repeated until the prototype is complete. Afterwards, the solid part is removed from the vat and rinsed clean of excess liquid. Supports are broken off and the model is then placed in an ultraviolet oven for complete curing. Because it was the first technique, stereolithography is regarded as a benchmark by which other technologies are judged. Early stereolithography prototypes were fairly brittle and prone to curing-induced wrapage and distortion, but recent modifications have largely corrected these problems.

Fig 2.2.1: Stereo lithography

2.2.2 Laminated Object Manufacturing

In this technique, developed by Helisys of Torrance, CA, layers of adhesive-coated sheet material are bonded together to form a prototype.. As shown in the figure below.

Fig2.2.2: Schematic diagram of laminated object manufacturing.

A feeder/collector mechanism advances the sheet over the build platform, where a base has been constructed from paper and double-sided foam tape. Next, a heated roller applies pressure to bond the paper to the base. A focused laser cuts the outline of the first layer into the paper and then cross-hatches the excess area (the negative space in the prototype). Cross-hatching breaks up the extra material, making it easier to remove during post-processing. During the build, the excess material provides excellent support for overhangs and thin-walled sections. After the first layer is cut, the platform lowers out of the way and fresh material is advanced. The platform rises to slightly below the previous height, the roller bonds the second layer to the first, and the laser cuts the second layer. This process is repeated as needed to build the part, which will have a wood-like texture. Because the models are made of paper, they must be sealed and finished with paint or varnish to prevent moisture damage.

Helisys developed several new sheet materials, including plastic, water-repellent paper, and ceramic and metal powder tapes. The powder tapes produce a "green" part that must be sintered for maximum strength. As of 2001, Helisys is no longer in business.

2.2.3 Selective Laser Sintering

Developed by Carl Deckard for his master’s thesis at the University of Texas, selective laser sintering was patented in 1989. The technique, shown in Fig, uses a laser beam to selectively fuse powdered materials, such as nylon, elastomer, and metal, into a solid object. Parts are built upon a platform which sits just below the surface in a bin of the heat-fusable powder. A laser traces the pattern of the first layer, sintering it together. The platform is lowered by the height of the next layer and powder is reapplied. This process continues until the part is complete. Excess powder in each layer helps to support the part during the build. SLS machines are produced by DTM of Austin, TX.

Fig 2.2.3: Schematic diagram of selective laser sintering.

2.2.4 Fused Deposition Modeling

In this technique, filaments of heated thermoplastic are extruded from a tip that moves in the x-y plane. Like a baker decorating a cake, the controlled extrusion head deposits very thin beads of material onto the build platform to form the first layer.

Fig2.2.4: schematic diagram of fused deposition modeling.

The platform is maintained at a lower temperature, so that the thermoplastic quickly hardens. After the platform lowers, the extrusion head deposits a second layer upon the first. Supports are built along the way, fastened to the part either with a second, weaker material or with a perforated junction.

2.3 3D printing Vs conventional technologies

3DP does not—and will not—replace completely conventional technologies such NC and high-speed milling, or even hand-made parts. Rather, one should regard 3DP as one more option in the toolkit for manufacturing parts. Figure depicts a rough comparison between 3DP and milling regarding the costs and time of manufacturing one part as a function of part complexity10. It is assumed, evidently, that the part can be manufactured by either technology such that the material and tolerance requirements are met.

Fig2.3 : 3DP vs. conventional machining

In order to decide on which technologies to utilize, various companies offering solutions for 3D printing were researched. The main difference between 3D printing and other rapid prototyping methods is the choice of materials, how these materials are deposited, fused, and solidified. 3D printing also enables items to be produced on a smaller scale, faster speed, less costly, and at a greater convenience than other additive manufacturing methods. Prior to purchasing a 3D printer, one must determine what the printed prototype will be used for.

2.4 Price comparision of different commercial 3D printers.

Table 2.4 : Price comparision of different commercial 3D printers

Printer	Cost (in ₹)	Power requirements (v)	Accuracy(mm)	Minimum print layer thickness (mm)	Max print volume	Print material
	18000	100-220	0.4	0.3	150x110x90	PLA
Solidoodle	30000	120-240	0.3	0.1	203x203x203	ABS
Printrbot	24000	110-240	-	0.1	102x102x102	PLA/ABS
Little3D	78000	110-220	0.1	0.1	135x120x175	PLA
Rapidbot	48000	100-240	0.027	0.2	220x220x220	PLA
Airwolf 3D	138000	110-240	0.04	0.1	300x200x178	PLA/ABS/Nylon/polycard
VASP	7099	110-240	0.4	,1	170x170x150	PLA

3. METHODOLOGY

3.1 Components

3.1.1 Frame

Ø It is to hold the machines together.

Ø Main purpose of providing frame is to avoid the disturbances occurring during the working of head.

3.1.2 Extruder

Fig 3.1.2 Extruder

It is also called as warm head which extrudes the warm plastics.
play vital role in the 3-D printer.
It moves in z direction with the assistance of motors.
Fan is used to cool the extruder .

Extruder parts includes-

A.Motor to push the raw material.

B.Nozzle chamber.

C. Heating coil.

D.Temperature sensor.

3.1.3 Controller

Fig 3.1.3 Arduino Mega 2560

Here we have used the arduino board.
It is based on the micro controller chip”MEGA MT2560”
This board consists of chip along with few driver camponents,power circuitry and a direct usb connection to a computer.
It has some firmware on board in the chip already to enable loading programs from usb on to the chip.

3.1.4 LCD Display

Fig 3.1.4 LCD Display

1. LCD displays the parameters of the components.

2. It has a slot for SD card to feed the model to be printed

3. It acts as a monitor for the microcontroller.

3.1.5 Stepper Motors

1. Stepper motors coupler withg belts and pulley is used to control the movement on different axis

2. It is also used to feed the filament to the extruder

3. One stepper motor is used for each X & Y and two more for z axis.

3.1.6 Switch mode power supply (SMPS)

Fig 3.1.6 SMPS

1. SMPS from old computers is used for the power supply for heating, Driving motors

2. It also acts as voltage regulator and rectifier

3.1.7 Heat bed

Fig 3.1.7 Heat Bed

A heated build platform (HBP) improves printing quality by helping to prevent warping. As extruded plastic cools, it shrinks slightly. When this shrinking process does not occur throughout a printed part evenly, the result is a warped part. This warping is commonly seen as corners being lifted off of the build platform. Printing on a heated bed allows the printed part to stay warm during the printing process and allow more even shrinking of the plastic as it cools below melting point. Heated beds usually yield higher quality finished builds with materials such as ABS and PLA. A HBP can also allow users to print without rafts.

3.2 Firmware comparision and selection

1) SPRINTER

Details	Description
Name : Sprinter Author(s) : Kliment, caru, tonok, tesla893. Status : Active as of Feb 2012.	Forked from Klimentkip. Seems to be a popular firmware.

Features

• SD card reader.

• Stepper extruder.

• Extruder speed control.

• Movement speed control.

• Constant or exponential acceleration.

• Heated build platforms.

2) TEACUP

Details	Description
Name : Teacup Author(s) : Traumflug, Triffid_hunter, jakepoz Status : Active as of August 2015	A dummy-proof firmware for many ATmega and ARM based controllers with emphasis on ease of use, high performance and clean code design.

Features

• Comes with Teacup Configtool for configuration and building, no text file editing.

• Moves steppers smoothly with up to 48 kHz on ATmega based controllers, 130 kHz on ARM based ones.

• Start-stop ramping, lookahead.

• Printing from SD card.

• Unlimited number of heaters, devices and temperature sensors.

• Support for USB-equipped ATmegas.

• Support for spindles, CNC-milling.

3) MARLIN

Details	Description
Name : Marlin Author(s) : Erik van der Zalm: Active as of February 2014; Bernhard Kubicek: Active as of November 2011 Status : Active as of June 2014	Development on this firmware appears to be very active. Forked from Sprinter and Grbl.

Features

• Look ahead (Keep the speed high when possible. High cornering speed.).

• High steprate.

• Interrupt-based temperature protection.

• Interrupt-based movement with real linear acceleration.

• Preliminary support for Matthew Roberts' advance algorithmFull endstop support.

• SD Card support.

• SD Card folders (works in Pronterface).

• LCD Support, graphical and character-based (Ideally 20x4, but 16x4 also supported.).

• LCD menu system for autonomous SD card printing, controlled by an click-encoder.

• EEPROM storage of configurable settings (e.g. max-velocity, max-acceleration, etc.).

• Arc support.

• Temperature oversampling.

• Dynamic Temperature setpointing aka "AutoTemp".

4) RepRap FIRMWARE

Details	Description
Name : RepRap Firmware Author(s) : Adrian Bowyer Status : DC42 and Chrishamm forks active as of April 2016	RepRap Firmware is intended to be a fully object-oriented highly modular control program for RepRap self-replicating 3D printers.

Features

• Look ahead (Keep the speed high when possible. High cornering speed.)

• High step rate.

• Interrupt-based temperature protection.

• Interrupt-based movement with real linear acceleration.

• Preliminary support for Matthew Roberts' advance algorithm.

• Full end stop support.

• SD Card support.

In comparison to all four above mentioned firm wares for this project we choosing forked version RepRap with few minor adjustment. Dumped to board using Arduino IDE 1.6.5.

3.3 Movement on different axis

3.3.1 Movement on Y-axis

1 This arrangement consists of four wooden blocks.

1. Each of block is connected through stainless steel rods.

2. Out of which two rods are made movable through radial bearings provided in that.where other two are made fixed.

3. A single stepper motor is coupled to the movable rods through belt over the pulleys.carriages are attached to these belts.

4. So as the motor runs which runs the rod in y direction.

3.3.2 MOVEMENT ON X-AXIS

1. For this two more rods are connected between carriages in a direction perpendicular to the y axis.

2. A single stepper motor is provided on the one of the carriage and pulley is provided on the other carriage.

3. The motor shaft is connected to pulley through the belt over which heat bed is attached to it.

4. So as motor runs bed along with belt also moves over the pulley through linear bearings.

1.3.3 MOVEMENT ON Z-AXIS

1. Here we have used two stepper motors.

2. The shaft of these stepper motors are connected to the threaded rods through the coupler.

3. Nuts are provided on each of the threaded rods over which wooden board is placed on it.

4. Now the extruder is placed on the board so as shaft rotates nuts on the threaded rod also moves either up or down depending on the direction of rotation.so in turn which moves the extruder.

3.4 The Basic Process of 3D Printing

Although several rapid prototyping techniques exist, all employ the same basic five-step process. The steps are:

Create a CAD model of the design
Convert the CAD model to STL format
Slice the STL file into thin cross-sectional layers
Construct the model one layer atop another
Clean and finish the model

3.4.1 CAD Model Creation:

First, the object to be built is modeled using a Computer-Aided Design (CAD) software package. Solid modelers, such as Google sketchup, tend to represent 3-D objects more accurately than wire-frame modelers such as AutoCAD, and will therefore yield better results. The designer can use a pre-existing CAD file or may wish to create one expressly for prototyping purposes. This process is identical for all of the RP build techniques.

3.4.2 Conversion to STL Format:

The various CAD packages use a number of different algorithms to represent solid objects. To establish consistency, the STL (stereolithography, the first RP technique) format has been adopted as the standard of the rapid prototyping industry. The second step, therefore, is to convert the CAD file into STL format. This format represents a three-dimensional surface as an assembly of planar triangles, "like the facets of a cut jewel." ⁶ The file contains the coordinates of the vertices and the direction of the outward normal of each triangle. Because STL files use planar elements, they cannot represent curved surfaces exactly. Increasing the number of triangles improves the approximation, but at the cost of bigger file size. Large, complicated files require more time to pre-process and build, so the designer must balance accuracy with manageability to produce a useful STL file. Since the STL format is universal, this process is identical for all of the RP build techniques.

3.4.3 Slice the STL File:

Fig 3.4.3:- Slice the STL File

In the third step, a pre-processing program prepares the STL file to be built. Several programs are available, and most allow the user to adjust the size, location and orientation of the model. Build orientation is important for several reasons. First, properties of rapid prototypes vary from one coordinate direction to another. For example, prototypes are usually weaker and less accurate in the z (vertical) direction than in the x-y plane. In addition, part orientation partially determines the amount of time required to build the model. Placing the shortest dimension in the z direction reduces the number of layers, thereby shortening build time. The pre-processing software slices the STL model into a number of layers from 0.01 mm to 0.7 mm thick, depending on the build technique. The program may also generate an auxiliary structure to support the model during the build. Supports are useful for delicate features such as overhangs, internal cavities, and thin-walled sections. Each RP machine manufacturer supplies their own proprietary pre-processing software.

STL file example could be seen at the end of the post

3.4.4 Layer by Layer Construction:

Fig 3.4.4 Layer by Layer Construction

The fourth step is the actual construction of the part. Using one of several techniques (described in the next section) RP machines build one layer at a time from polymers, paper, or powdered metal. Most machines are fairly autonomous, needing little human intervention.

3.4.5 Clean and Finish:

The final step is post-processing. This involves removing the prototype from the machine and detaching any supports. Some photosensitive materials need to be fully cured before use. Prototypes may also require minor cleaning and surface treatment. Sanding, sealing, and/or painting the model will improve its appearance and durability.

3.5 Implemented G-Codes

G codes

G1 - Coordinated Movement X Y Z E

G2 - CW ARC

G3 - CCW ARC

G4 - Dwell

G10 - retract filament according to settings of M207

G11 - retract recover filament according to settings of M208

G28 - Home all Axis

G29 - Detailed Z-Probe, probes the bed at 3 or more points. Will fail if you haven't homed yet.

G30 - Single Z Probe, probes bed at current XY location.

G31 - Dock sled (Z_PROBE_SLED only)

G32 - Undock sled (Z_PROBE_SLED only)

G90 - Use Absolute Coordinates

G91 - Use Relative Coordinates

G92 - Set current position to coordinates given

M Codes

M0 - Unconditional stop - Wait for user to press a button on the LCD (Only if ULTRA_LCD is enabled)

M1 - Same as M0

M17 - Enable/Power all stepper motors

M18 - Disable all stepper motors; same as M84

M20 - List SD card

M21 - Init SD card

M22 - Release SD card

M23 - Select SD file (M23 filename.g)

M24 - Start/resume SD print

M25 - Pause SD print

M26 - Set SD position in bytes (M26 S12345)

M27 - Report SD print status

M28 - Start SD write (M28 filename.g)

M29 - Stop SD write

M30 - Delete file from SD (M30 filename.g)

M31 - Output time since last M109 or SD card start to serial

M32 - Select file and start SD print

M80 - Turn on Power Supply

M81 - Turn off Power Supply

M82 - Set E codes absolute (default)

M83 - Set E codes relative while in Absolute Coordinates (G90) mode

M84 - Disable steppers until next move,

M85 - Set inactivity shutdown timer with parameter S<seconds>. To disable set zero (default)

M92 - Set axis_steps_per_unit - same syntax as G92

M104 - Set extruder target temp

M105 - Read current temp

M106 - Fan on

M107 - Fan off

M109 - Sxxx Wait for extruder current temp to reach target temp. Waits only when heating

Rxxx Wait for extruder current temp to reach target temp. Waits when heating and cooling

M112 - Emergency stop

M114 - Output current position to serial port

M115 - Capabilities string

M117 - display message

M119 - Output Endstop status to serial port

M140 - Set bed target temp

M150 - Set BlinkM Color Output R

M190 - Sxxx Wait for bed current temp to reach target temp. Waits only when heating

Rxxx Wait for bed current temp to reach target temp. Waits when heating and cooling

M201 - Set max acceleration in units/s^2 for print moves (M201 X1000 Y1000)

M202 - Set max acceleration in units/s^2 for travel moves (M202 X1000 Y1000)

M206 - set additional homing offset

M300 - Play beep sound S<frequency Hz> P<duration ms>

M301 - Set PID parameters P I and D

M302 - Allow cold extrudes, or set the minimum extrude S<temperature>.

M304 - Set bed PID parameters P I and D

M400 - Finish all moves

M406 - Turn off Filament Sensor extrusion control

M600 - Pause for filament change X[pos] Y[pos] Z[relative lift] E[initial retract] L[later retract distance for removal]

M350 - Set microstepping mode.

M928 - Start SD logging (M928 filename.g) - ended by M29

M999 - Restart after being stopped by error

4. APPLICATION OF 3D PRINTERS

The concept of custom manufacturing is exciting to nearly everyone, but it always seems to be something that will happen in the “future”. Gibson was right and the following list of applications for 3D printers show the truth in the saying “The future is here. It’s just not evenly distributed yet.” The following items are all available for purchase or are being used in industry now. We are still a long way from Replicators like the ones from Star Trek: The Next Generation, but we probably won’t have to wait till the 24th century either.

4.1. Art

3D printing allows artists to create objects that would be incredibly difficult, costly, or time intensive using traditional processes. These sculptures by Bathsheba Grossman are exquisitely complex and manufactured using a laser sintering process.

4.2. Action Figures

Blood Elves and band mates can both be brought to life using 3D printers. These two were created using Zcorp. machines which apply glue ink and powder in fine layers slowly creating a replica of one of your characters. Figure Prints allows you to create characters from Warcraft, Rock band and Spore printing services are coming soon. A number of other sites allow you to pull data from Second Life and your own 3D programs.

4.3. Jewelry

Jewelry makers were some of the first to use 3D printing in their manufacturing process, however they do not use metal printers, but rather ones that use wax. In a process called “investment casting” a piece of jewelry is sculpted or printed out of wax. Plaster is then poured on either side. Molten metal is poured onto the wax which melts out leaving a metal version of your wax sculpt in its place in the plaster. This piece is then finished and polished by a jeweler. Many independent jewelers have been using high tech printers in their businesses and an innovative company called Paragon Lake has combined this process with web based design tools to offer an infinite inventory to the masses of jewelry stores.

4.4. Prototypes

Prototyping in product development is currently the biggest use of 3D printing technology. These machines allow designers and engineers to test out ideas for dimensional products cheaply before committing to expensive tooling and manufacturing processes.

4.5. Models

Sales folks lives get much easier when you can have models like this of your product printed up for show and tell.

4.6. Medicine

3D World of Warcraft characters are cool, but these tools have the power to help save lives. Surgeons are using 3d printers to print body parts for reference before complicated surgeries. Other 3D printers are used to create bone grafts for patients who have suffered traumatic injuries. Looking further in the future scientist are working on PRINTING replacement organs. Personal Fabrication indeed!

4.7. Crime Scene Reconstruction

3D printing can save lives, bring Orcs to life, and solve crimes. 3D printing/scanning is used in forensics in real life and as a prop for dramatic effect in this clip from CSI.

5. ADVANTAGES OF 3D PRINTING

The most successful companies have adopted 3D printing as a critical part of the iterative design process to:

5.1 Increase Innovation

Print prototypes in hours, obtain feedback, refine designs and repeat the cycle until designs are perfect.

5.1 Improve Communication

Hold a full color, realistic 3D model in your hands to impart infinitely more information than a computer image.
Create physical 3D models quickly, easily and affordably for a wide variety of applications.

5.2 Speed Time to Market

Compress design cycles by 3D printing multiple prototypes on demand, right in your office.

5.3 Reduce Development Costs

Cut traditional prototyping and tooling costs.
Identify design errors earlier.
Reduce travel to production facilities.

6. LIMITATIONS OF 3D PRINTING

Although three-dimensional printing has many advantages, it also has a few disadvantages that come with it:

Current 3D printing materials for investment casting tend to yield sporadically rough surfaces.
Sometimes encourages informal design methods which may cause more problems to fix.
It may not be suitable for large sized applications.

The user may have very high expectations about the prototype’s performance and it might fail in the exact replication of the real product or systems.
3-D printers are still expensive.
Although 3-D printers have the potential of creating many jobs and opportunities, they might also put certain jobs at risk (for example, you can make your toys at home so toy stores and toy makers might go out of business).
3DP parts have a ribbed and little rough appearance due to layering beads of plastic.
Could be a slow process for large build volume parts.

7. COST ESTIMATION OF OUR PROJECT

Table 7 : Cost Estimation of our Project

Sl no	Component	Quantity	Price(₹ )
1	Arduino, Ramps & LCD Display	1	3500
2	Wires and Connectors	1	150
3	Axial Bearing	6	410
4	Shaft	6	550
5	Extruder Block	1	499
6	Stepper coupler	2	230
7	Threaded Rod	2	140
8	Fastners	50	75
9	Pulley	5	480
10	Extruder	1	510
11	ABS plastic(10m)	1	400
12	End Switches	3	75
13	Thermistor	1	80
Total			7099

8. THE FUTURE OF 3D PRINTING

Firstly lets clarify what is meant by 3D printing, well in a nut shell it is a way of fabricating objects designed on computer

, for example if you designed a mug using computer aided design

, within a few hours you could have the real thing sitting in front of you.
It is possible to watch your very creations come to life in true Star Trek fashion, before your very eyes. To go into more detail, currently printers are fairly slow, limited and not tremendously precise. A home 3D printer will typically set up back about 15-50k Rs, but this is cheap considering the first commercially available printers cost at least ten times that amount. 3D printers presently are capable of fabricating objects using silicon and certain types of metal, other substances that have been tested are plaster, play-doh and even chocolate!

A home 3D printer is about the size of a Microwave and connects directly to a desktop computer running software that controls its operation. It then creates objects layer-by-layer by squeezing material from a mechanically-controlled syringe. Unfortunately printers are somewhat limited in the sense they still produce a fairly rough end product and the time scale it takes to print an object is considerable.

           Despite all the technical implications, there are huge possibilities for the future of 3D printing. All ground breaking technology starts somewhere, for example in the case of the PC, mainframes had existed for years, but personal computing only took off in the late seventies. A cheap self-assembly computer called the Altair 8800, launched in 1975, sparked the rapid development of personal computing. In similar circumstances self-assembly 3D printers hope to spark the same rapid development in rapid prototyping.

           There are a number of different 3D printers available on the market today, all with slightly different advantages, disadvantages, quirks and features. Some interesting projects include an open source 3D printer which has successfully been used to fabricate better parts to replace existing parts on the printer itself. The ultimate goal of 3d printers is to perfectly replicate themselves, allowing much more cost effective manufacturing.

         The future for 3D printing seems very promising, it is the fastest growing part of the rapid-prototyping industry with revenues this year expected to be approximately a billion US dollars. Many industries are showing huge amounts of interest and are seem great potential in different applications where they could utilize three dimensional printing. The US army have experimented using rapid prototyping to create parts for broken tanks, guns and other hardware in combat situations. Businesses believe a rapid prototyping machine could prove invaluable in showing factories how to assemble parts remotely, for example in China. Even NASA has requested a high resolution machine to manufacture crucial parts in space.