(Đồ án hcmute) design and implementation of a multicolor 3d printer

MINISTRY OF EDUCATION AND TRAINING
HCMC UNIVERSITY OF TECHNOLOGY AND EDUCATION

GRADUATION THESIS
MECHATRONIC ENGINEERING TECHNOLOGY

DESIGN AND IMPLEMENTATION OF
A MULTICOLOR 3D PRINTER

ADVISOR: VU QUANG HUY, PhD.
PHAM BACH DUONG, M.Eng.
STUDENT’S NAME: PHAM XUAN CHIEN
STUDENT’S ID: 13146023
STUDENT’S NAME: NGHIEM LUONG HAI
STUDENT’S ID: 13146057
STUDENT’S NAME: HA XUAN THANG
STUDENT’S ID: 13146197

SKL 0 0 5 3 6 6

Ho Chi Minh city, July 2017

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UNIVERSITY OF TECHNOLOGY AND EDUCATION
FACULTY FOR HIGH QUALITY TRAINING
DEPARTMENT OF MECHATRONICS

GRADUATION THESIS

DESIGN AND IMPLEMENTATION OF
A MULTICOLOR 3D PRINTER
ADVISOR:

VU QUANG HUY, PhD.
PHAM BACH DUONG, M.Eng.

STUDENT’S NAME: PHAM XUAN CHIEN (13146023)
NGHIEM LUONG HAI (13146057)
HA XUAN THANG

(13146197)

ACADEMIC BATCH: 2013 - 2017
MAJOR: MECHATRONICS

Ho Chi Minh City, July 2017

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SOCIALIST REPUBLIC OF VIETNAM
Independence - Freedom - Happiness
----***----

Ho Chi Minh City, May 31th 2017

MISSION OF THESIS

Student’s name: Pham Xuan Chien

Student’s ID: 13146023

Nghiem Luong Hai

13146057

Ha Xuan Thang

13146197

Major: Mechatronics

Class: 13146CLC

Advisor: Vu Quang Huy, Ph.D

Phone number:

Delivery date: 20/2/2017

Submission date: 23/7/2017

1. Title of thesis: Design and implementation of a multicolor 3D printer
2. The original data, documents:
-Documents about assembly and calibration of 3D printer.
-Datasheets of electronic components.
-Articles of multicolor methods.
-The Firmware and slicer software from open source

3. Main content:
-Research on rapid prototyping.
-Design a model of 3D printer and implement it.
-Experiment 3D printed products through for analyzing and evaluating product quality.

4. Product:
-A 3D printer has size of 200x200x100 mm, solid mechanics and stable operation.
-3D printed products have diverse colors, high precision and good surface quality.
Program Chair

Advisor

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SOCIALIST REPUBLIC OF VIETNAM
Independence - Freedom - Happiness
----***----

ADVISOR’S COMMENT
Student’s name: Pham Xuan Chien

Student’s ID: 13146023

Nghiem Luong Hai

13146057

Ha Xuan Thang

13146197

Major: Mechatronics
Title of thesis: Design and implementation of a multicolor 3D printer
Advisor’s name: Pham Bach Duong, M.Eng.
COMMENTS
1. The content of thesis and workload allocated:
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2. Advantages:
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3. Improvement points:
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4. Thesis defense approval: Yes  No 
5. Evaluation remark:
..........................................................................................................................................................
6. Grade: ............................. (in word: ..............................................................................................)
Ho Chi Minh City, July 2017
Advisor
(Name, signature)

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SOCIALIST REPUBLIC OF VIETNAM
Independence - Freedom - Happiness
----***----

REVIEWER’S COMMENT
Student’s name: Pham Xuan Chien

Student’s ID: 13146023

Nghiem Luong Hai

13146057

Ha Xuan Thang

13146197

Major: Mechatronics
Title of thesis: Design and implementation of a multicolor 3D printer
Reviewer’s name: Nguyen Vu Lan, Ph.D
COMMENTS
1. The content of thesis and workload allocated:
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
2. Advantages:

..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
3. Improvement points:
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
4. Thesis defense approval: Yes  No 
5. Evaluation remark:
..........................................................................................................................................................
6. Grade: ............................. (in word: ..............................................................................................)
Ho Chi Minh City, July 2017
Reviewer
(Name, signature)

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ACKNOWLEDGEMENT
Firstly, we wish to thank our parents and our friends for their supports and
encouragement throughout our study. Secondly, we would like to express our
gratitude to Dr. Vu Quang Huy - the project supervisor, for his patient guidance,
enthusiastic encouragement and invaluable comments on this project. Thanks to his
advices and assistances in keeping our progress on schedule. Our grateful thanks are
also extended to Mr. Trung – the specialist in 3D printing workshop, for his supports
in offering us the resources, troubleshooting and increasing the qualification of our
3D printing products. They did contributed a lot in helping us to successfully
complete project “Design and implementation of a multicolor 3D printer”. In the

implementation process of the project, there would certainly be some inevitable
mistakes, we do hope to receive your comments for future improvements.
Ho Chi Minh City, May 31th, 2017
Group of students: Pham Xuan Chien
Nghiem Luong Hai
Ha Xuan Thang

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ABSTRACT
In this project “Design and implementation of a multicolor 3D printer”, our group
sets the goal to make a 3D printer that can print not only in single color but also in
multiple colors automatically without changing the filament manually. The printer is
designed according to the Cartesian structure, with dimension of printing is
200x200x150mm.
The 3D printer model is designed on Solidworks according to the intended size. Based
on the model, we analyze and calculate to purchase and outsourcing materials. For
multicolor printing, we use the Diamond Hotend that has three inputs, one output and
a small color mixing chamber. Repetier host is used to choose color for product and
send G-code to Arduino.
After 3 months of project implementation, our group has achieved some results. The
3D printer can print the product that has 200x200x100 mm dimension. It operates
smooth with an average speed of 40 to 60 mm / s. Products with a slight deviation of
0.1 to 0.2 mm. With the use of Diamond Hotend, the 3D printer prints products that
has from one to four colors are quite good, the surface of them is smooth. When
printing five-color products, they are quite bad with the surface deformation.
Filament usually get stuck on Diamond Hotend.

Keywords: Rapid prototying, 3D printing, multicolor, Diamond Hotend, filament
jam

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CONTENTS
COVER PAGE ......................................................................................................................... PAGE
MISSION OF THESIS ......................................................................................................................i
ADVISOR’S COMMENT ................................................................................................................ ii
REVIEWER’S COMMENT ........................................................................................................... iii
ACKNOWLEDGEMENT ............................................................................................................... iv
ABSTRACT ....................................................................................................................................... v
LIST OF ABBREVIATIONS........................................................................................................ viii
LIST OF TABLES ........................................................................................................................... ix
LIST OF FIGURES AND CHARTS ............................................................................................... x
CHAPTER 1: OVERVIEW ............................................................................................................ 1
1.1. The necessary of the thesis ....................................................................................................... 1
1.2. Scientific and practical meanings ............................................................................................ 1
1.3. Research objectives of the thesis. ............................................................................................. 1
1.4. Object and goal of the study ..................................................................................................... 1
1.5. Research Methodology.............................................................................................................. 2
1.6. Introduction to rapid prototyping technology [1] .................................................................. 2
1.6.1. General principles .............................................................................................................. 3
1.6.2. Features ............................................................................................................................... 3
1.7. The introduction and development of the RAP method [9] .................................................. 3
1.7.1. Early period: Manual Sampling ....................................................................................... 3
1.7.2. Second period: virtual prototyping or creation software ............................................... 3

1.7.3. Third period: RAP process ............................................................................................... 4
1.8. Application of RAP ................................................................................................................... 4
CHAPTER 2: LITERATURE REVIEW ....................................................................................... 7
2.1. Some methods of template creation. [10] ................................................................................ 7
2.1.1. SLA method (Stereo Lithography Apparatus) ................................................................ 7
2.1.2. Solid Ground Curing (SGC) ............................................................................................. 8
2.1.3. LOM (Laminated Object Manufacturing) ...................................................................... 9
2.1.3. SLS (Selective Laser Sintering)....................................................................................... 10
2.1.4. 3D FDM Printing Method (Fused Deposition Manufacturing) ................................... 11
2.1.5. Analysis of 3D FDM (Fused Deposition Manufacturing) ............................................. 12
2.2. Multicolor printing solutions ................................................................................................. 13
2.2.1. Using multi nozzle ............................................................................................................ 13
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2.2.2. Palette method [4] ............................................................................................................ 15
2.2.3. Diamond Hotend [7]......................................................................................................... 16
2.2.4. Multicolor filament [11]................................................................................................... 17
2.3. The effect of temperature on the operation of the printing [8] ........................................... 18
CHAPTER 3: DESIGN AND ANALYSIS ................................................................................... 20
3.1. Mechanical design ................................................................................................................... 20
3.1.1. The structure of 3D printer [3] ....................................................................................... 20
3.1.2. Analysis of axis-driven motors ........................................................................................ 23
3.1.3. Analysis of transmission mechanisms ............................................................................ 26
3.1.4. Check the deviation on the axes ...................................................................................... 28
3.2. Electronic design ..................................................................................................................... 29
3.2.1. Controller unit [1] ............................................................................................................ 29
3.2.2. Driver modules. ................................................................................................................ 31

3.2.3. Driver ICs ......................................................................................................................... 31
3.3. Control system ......................................................................................................................... 33
3.3.1. Repetier Console .............................................................................................................. 33
3.3.2. Programming in Arduino ................................................................................................ 34
3.3.3. Adjust PID temperature of extruder [6] ........................................................................ 35
3.3.4. Custom Slicing with Slice Software ................................................................................ 36
3.3.5. Multi-material printing with Repetier Host .................................................................. 36
3.3.6. Interpolation ..................................................................................................................... 38
3.3.7. Convert data from CAD to G-code................................................................................. 39
3.3.8. Read and process G-code data ........................................................................................ 40
CHAPTER 4: EXPERIMENTS AND RESULTS ....................................................................... 42
4.1. Modes of experiments: ............................................................................................................ 42
4.1.1. Target value ...................................................................................................................... 42
4.1.2. Testing criteria ................................................................................................................. 42
4.1.3. Manually control: ............................................................................................................. 42
4.1.4. Automatic control: ........................................................................................................... 43
4.2. Analysis and comments: ......................................................................................................... 48
4.3. Bill of materials ....................................................................................................................... 51
CHAPTER 5: CONCLUSION AND RECOMMENDATIONS ................................................ 52
REFERENCES ............................................................................................................................... 53
APPENDIX ..................................................................................................................................... 54

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LIST OF ABBREVIATIONS
ABS

Acrylonitrile Butadiene Styrene

CNC

Computer Numerical Controlled

CAD

Computer Aided Design

CAE

Computer-aided engineering

CAM Computer-aided manufacturing
CMM Coordinate Measuring Machine
FDM

Fused Deposition Manufacturing

LOM

Laminated Object Manufacturing

PLA

Poly Lactic Acid

FDM

Fused Deposition Manufacturing

STL

Stereo lithography

SLA

Stereo Lithography Apparatus

SGC

Solid Ground Curing

SLS

Selective Laser Sintering

SLS

Selective Laser Sintering

RAP

Rapid prototyping

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LIST OF TABLES
Table 4. 1 Run from 1 point .......................................................................................................... 42
Table 4. 2 Run continuously 1 mm ............................................................................................... 43
Table 4. 3 Angle error test with sample 1 and 2 .......................................................................... 47
Table 4. 4 Test height and diameter of sample 3 ........................................................................ 47

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LIST OF FIGURES AND CHARTS
Figure 1. 1 The engine of plane is 3D printed for checking error................................................ 5
Figure 1. 2 Mold by 3D printing technology .................................................................................. 5
Figure 1. 3 The joints are made form a 3D printer ....................................................................... 6
Figure 2. 1 SLA Modeling Methodology ........................................................................................ 7
Figure 2. 2 SGC Modeling Methodology........................................................................................ 8
Figure 2. 3 LOM Modeling Methodology ...................................................................................... 9
Figure 2. 4 SLS Modeling Methodology....................................................................................... 10
Figure 2. 5 FDM Modeling Methodology ..................................................................................... 11
Figure 2. 6 Dual nozzles ................................................................................................................. 14
Figure 2. 7 Filament stuck on the print ........................................................................................ 14
Figure 2. 8 Palette printing............................................................................................................ 15
Figure 2. 9 Structure of Palette ..................................................................................................... 15
Figure 2. 10 Product of Palette...................................................................................................... 16
Figure 2. 11 Diamond Hotend ....................................................................................................... 17
Figure 2. 12 Multiclor filament and product ............................................................................... 18
Figure 2. 13 Compare the temperature distribution between nozzles have good heat sink and
don’t have good heat sink .............................................................................................................. 18

Figure 2. 14 Material jam at the location exposed two heat zones ............................................ 19
Figure 2. 15 Add material at the heat transfer location[6] ......................................................... 19
Figure 3. 1 Cartesian structure [8] ............................................................................................... 20
Figure 3. 2 Delta structure [8] ....................................................................................................... 21
Figure 3. 3 Polar structure [8]....................................................................................................... 22
Figure 3. 4 Design model in Solidworks ....................................................................................... 23
Figure 3. 5 Model in reality ........................................................................................................... 23
Figure 3. 6 Stepper motor.............................................................................................................. 23
Figure 3. 7 DC motor ..................................................................................................................... 24
Figure 3. 8 Servo motor ................................................................................................................. 24
Figure 3. 9 Lead screw nut ............................................................................................................ 26
Figure 3. 10 Ball screw ................................................................................................................... 27
Figure 3. 11 Belt ............................................................................................................................. 27
Figure 3. 12 Check the flatness of the bed with bubble level ..................................................... 28
Figure 3. 13 Check the flatness of the X axis ............................................................................... 28
Figure 3. 14 Check the equality of the two Z axes ....................................................................... 29
Figure 3. 15 Control block diagram of the 3D printer ................................................................ 29
Figure 3. 16 Arduino Mega 2560 [9] ............................................................................................. 29
Figure 3. 17 RAMPS 1.4 ................................................................................................................ 31
Figure 3. 18 DRV8825 [10] ............................................................................................................ 32
Figure 3. 19 Schematic of DRV8825 [10] ..................................................................................... 33
Figure 3. 20 Interface of Repetier host ......................................................................................... 34
Figure 3. 21 Manual of Repetier host ........................................................................................... 34
Figure 3. 22. OVERALL CONTROL DIAGRAM OF ARDUINO ........................................... 35
Figure 3. 23 Control PID of temperature..................................................................................... 35
Figure 3. 24 Adjust PID on Marlin firmware .............................................................................. 36
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Figure 3. 25 AMF file ..................................................................................................................... 36
Figure 3. 26 Combine STL file ...................................................................................................... 37
Figure 3. 27 Use Meshmixer to cut STL file ................................................................................ 37
Figure 3. 28 Circular Interpolate.................................................................................................. 39
Figure 3. 29 Diagram convert data from CAD to G-code .......................................................... 39
Figure 3. 30 Flowchart of reading and processing G-code data ................................................ 40
Figure 4. 1 Test and mix color....................................................................................................... 43
Figure 4. 2 Colors of our 3D printer ............................................................................................. 43
Figure 4. 3 Products with single color: red, cyan, yellow ........................................................... 44
Figure 4. 4 Mixing color products ................................................................................................ 44
Figure 4. 5 Products with 2 or 3 independent color .................................................................... 45
Figure 4. 6 Printing with “Wipe and prime tower” .................................................................... 45
Figure 4. 7 First layer .................................................................................................................... 45
Figure 4. 8 Infill level ..................................................................................................................... 46
Figure 4. 9 Samples is used for precise test .................................................................................. 46
Figure 4. 10 Filament stuck in Teflon tube .................................................................................. 48
Figure 4. 11 High temperature ...................................................................................................... 49
Figure 4. 12 Error product due to filament jam.......................................................................... 49
Figure 4. 13 The filaments flow out and stick on the nozzle....................................................... 49
Figure 4. 14 Deviated product ....................................................................................................... 50

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CHAPTER 1: OVERVIEW
1.1. The necessary of the thesis
Nowadays, the applications of fast shaping respond the practical needs which is the

basis for the development of RAP machines (3D printers). Applicability in many
areas such as product modeling, health and education, architecture...
The 3D printing technology development will help the production process as well as
the design stage cut down on product creation time, bringing the idea of real things
in order to analysis more easily. It also gives the designer more flexibility, creativity
when it comes to ideas that are not afraid how to create that product, and how long it
takes to create it. So the 3D printing is the best RAP tool.
1.2. Scientific and practical meanings
For the purpose of studying and researching field the 3D printing group has chosen
"Design and implementation of a multicolor 3D printer" project with the following
objectives:
 Join the study and learn the RAP 3D printing technology
 Practical the 3D printing application.
 Research products to meet commercial needs.
1.3. Research objectives of the thesis.
 Design drawing and implement the mechanic of the 3D printer.
 Developing a 3D printers creates colorful products
 Find out some printing errors of the 3D printing methods and come up with a
solution based solution in the experiment.
1.4. Object and goal of the study
1.4.1. Object of study
 3D printer with Prusa I3 structure.
 FDM (Fused Deposition Manufacturing) 3D printing method, using PLA to
create samples.

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1.4.2. Goal of the study
Structure
Print dimension
Nozzle
Precise
Material
Number of color

Cartesian structure
200x200x150
Diamond Hotend
0.1-0.3 mm
PLA and ABS
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1.5. Research Methodology
We use top down method to apply in this project.
- Self-collected data:
+ Test axes of the 3D printer to find the tolerance, working precision of its.
+ Experiment the 3D printer at different speeds and temperatures to find the effect of
these factors on the product to find out the appropriate parameters print the product.
+ Print detailed patterns to assess the profile, tolerance.
+ Coordinate the color of the plastic rolls of the machine to find the color printing
machine.
- Reference data:
+ Set multi-color printing on the software
+ Design model and nozzle holder from the manufacturer
+ Reference from the 3D printer project of the previous senior and suggestions of
friends who used to make printers
+ Common mistakes when printing products.

1.6. Introduction to rapid prototyping technology [1]
Rapid prototyping is a group of techniques used to quickly fabricate a scale model of
a physical part or assembly using three-dimensional computer aided design (CAD)
data. Construction of the part or assembly is usually done using the 3D printing or
"additive layer manufacturing" technology.
RAP technology can be known as a kind of technology that can directly create one
3D object with very short time, usually only one operation with the support of
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CAD software packages to create object models that serve as databases for RAP
machines. The model body is made up of a suitable material depending on the
direction RAP method.
The 3D printing is one of the RAP methods that make up a 3D object by stacking
each layer of material on top of each other until the complete shape of the object.
Each layer is a thin and horizontal material slice.
1.6.1. General principles
Materials are added and bonded together to form a non-cutting material such as
traditional machining methods. The sample is produced in a layered pattern, the
next layer is stacked with the previous layer.
1.6.2. Features






Allows the creation of complex shapes that cannot be machined

Conventional machining methods.
Significant reduction in machining time.
Imaging directly from CAD data.
Allows creation of complex shapes.

1.7. The introduction and development of the RAP method [9]
The modeling process is divided into three periods. Two periods later just born in
about 20 years. Similar to computer-aided modeling, the physical substance of the
sample was only developed during the third period.
1.7.1. Early period: Manual Sampling
The first period was born a few centuries ago. In this period, the typical pattern is no
high complexity and making an average sample takes about 4 weeks. Modeling
depends on workmanship and performs extremely heavy tasks. To this day, this
method of manual sampling is still widely used. For example, in the universities of
fine art, there is still use it
1.7.2. Second period: virtual prototyping or creation software
The second period of modeling developed very early, around the mid-70s. This time,
there is software for creating prototypes or virtual templates. The application of CAD
/ CAE / CAM has become very popular. Modeling software will draw on computer
the thinking, the new ideas. These samples as a physical model: tested, analyzed and
measured by stress and will be adjusted accordingly if they are not satisfactory. Such
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as stress analysis and predictable fluid surface tension because it is possible to
accurately determine the properties and properties of the material.
Moreover, the samples in this period became much more complex than the first period
(about two times). Therefore, the time required for modeling tends to be increased to

about 16 weeks, the physical properties of the sample still depends on the basic
prototyping method. However, the use of precision machining has better improve the
physical properties of the sample.
Along with the advancement of the RAP sector in the third period, there is great
support of virtual prototyping. However, there are still controversy over the limits of
the RAP technology such as: the limitation of material (or because of the high cost or
the usage of each material is not the same to create details).
1.7.3. Third period: RAP process
Partial physical properties of the product during the RAP process are also known
come. The hollow form factor is suitable for production on elevators or technology
production class. This technology demonstrates the development of prototype
development in the third period.
The invention of RAP devices is an important invention. This has met the
requirements of the business world in this period: reduced time production, the
complexity of the sample increases, decreases the cost. At this time consumers require
products both in terms of quality and design, the complexity of the details are
increased, triple the level of complexity that details were made in the years of 70. But
thanks to RAP technology the average time to create one detail is only lasts 3 weeks
than 16 weeks in the second period. In 1988, over 20 RAP technology has been
studied. We see that the need to create the original product template is an essential
need in the production process, before mass production, every product needs to create
a sample of the product first to test the feasibility and feasibility. If the more accurate
a product is, the quicker you will be, the mistakes made in the production process
later and the more money is saved how much production costs. So "RAP technology"
carries the full meaning of it, “technology”: ensure accuracy, "RAP" ensure fast time.
1.8. Application of RAP
Develop new products
This is the most important application of RAP, in the process development new
product, it shows the physical phenomena of the designs that we cannot observe to

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the computer model, including the design aspects, help for the designer evaluate the
product in the best way before entering into mass design.
Test the functionality of the product

Figure 1. 1 The engine of plane is 3D printed for checking error [9]

Based on the 3D model, it is difficult to guarantee that a product can be produced the
requirements of working, assembling ... especially with the gear details, gearbox,
cam, eccentric shaft or coupler, joystick ... RAP will help engineers and designers
handle those problems. RAP technology now can "print 3D" assembled details, even
in different colors.
Rapid Tooling
RAP is a very powerful application in making molded die parts, silicon, composite,
vacuum shaping...The traditional molding process is complex, time-consuming and
costly, wastes time from design to production, the application of technology RAP
into the field will provide a major driving force for the development of technology
creation mold, bringing high economic efficiency to this industry.

Figure 1. 2 Mold by the 3D printing technology [9]

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Application in medicine
In medicine, RAP technology is used to make medical models, bone replacement
implants and surgical aids.
Artificial bone: There are accidental fractures of the bones on the body and
unrecoverable. The requirement is to recreate the corresponding bone to implant with
high precision. To do that, people use reverse technology. RAP technology is also
widely used in dentistry

Figure 1. 3 The joints are made form a 3D printer [9]

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CHAPTER 2: LITERATURE REVIEW
2.1. Some methods of template creation [10]
2.1.1. SLA method (Stereo Lithography Apparatus)
A technique uses UV laser to solidify a liquid to create bonding layers continuously
until the product is finished, the minimum thickness of each layer can reach 0.06mm,
very accurate. Can imagine this technique as follows: put a base in the barrel contains
liquid material, laser beam moves (according to design) to the top surface of liquid
material in the cross-sectional shape of the product makes the material layer hard
again. The bracket containing the hardened material layer is lowered to create a new
layer. The other is done further until the finished product.

Figure 2. 1 SLA Modeling Methodology [10]

Advantages:
 Stable and fully automated system.

 High accuracy. Typical tolerances are approximately
 0,0125mm.
 Good surface gloss.
 High resolution is suitable for complex details.
Disadvantages:






Product warped.
The price is slightly high.
Limited use of materials.
Must be post-processing stage.
High cost of operation and maintenance.

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2.1.2. Solid Ground Curing (SGC)
It is also a method of hardening each layer. Unlike the SLA, it is not use point laser
source that uses ultraviolet light beams to project the entire surface shielded through
a mask. The exposed material will solidify into a layer. The mask is a negative film
of cut section.

Figure 2. 2 SGC Modeling Methodology [10]

Advantages:
 Parallel processing system: the process of sample preparation and processing
occurs in parallel therefore
 Saving time by 25-50%, reducing internal stresses and product warping
 Uniform product identity
 Multiple products can be produced at the same time.
Disadvantages:






The price is slightly high, the equipment is noisy
The materials used are restricted.
Must be post-processing stage
High cost of operation and maintenance
The wax must be removed from the finished product.

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2.1.3. LOM (Laminated Object Manufacturing)
Use sheet material with adhesive coating (mainly paper but also can be used plastic
sheet, sheet metal etc.). Laser source creates individual layers of cut sections by
cutting plates material along the boundary of the body section. Layers are pasted on
each other thanks to heating roller system

Figure 2. 3 LOM Modeling Methodology [10]

Advantages:
 Diverse, inexpensive materials. In principle can use materials: paper, plastics,
metals, composites and ceramics.
 High accuracy is better than 0.25 mm. By cutting materials instead solidifying
it, the system can protect the original properties of the material.
 No structural support is needed.
 High speed, faster than other layer methods because the laser does not cut
 The whole area that only sweeps in the outer perimeter. Therefore, the material
is thick and thin, same cutting speed.
 There is no phase change during the fabrication process, so shrinkage is
avoided of materials.
 Non-toxic and polluted environment.
Disadvantages:
 No excess material is recovered. Curvature of detail is usually the main
problem
 Of the LOM method.

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 Remove the product from the support structure.
 The surface gloss is not high.
2.1.3. SLS (Selective Laser Sintering)
A laser sintering method. After the rollers spread out on the table with a layer of
powder with a predetermined thickness, the laser source will sweep over the surface
need to create class. In that area the material particles will stick together to form a

layer. Each vertical movement of the equipment system will form the next layer. The
method of the 3D Printing works according to the principle of "ink jet". A special
colloidal ink was sprayed onto a flat, hardened plastic powder. So they are created a
layer and each layer gradually created the object.

Figure 2. 4 SLS Modeling Methodology [10]

Advantages:
 The amount of material that goes into the High Through-put that helps RAP
process quickly.
 Diverse materials, not expensive.
 Safety materials.
 Don’t need support structure.
 Reduce stress distortion.
 Reduce the stages of post-processing such as just spraying sand.
 No post-curing.
 Made many details at the same time.

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Disadvantages:
 Surface roughness.
 Details in porosity.
 The first layer may require a substrate to reduce the thermal effect (such as
bending trousers).
 The density of details is not identical.
 Change material needs to thoroughly clean the machine

2.1.4. 3D FDM Printing Method (Fused Deposition Manufacturing)
Use flow-able wire material, such as 3D ABS plastic, PLA. Wire over the head
heating will be plasticized and spread on the floor in accordance with the profile of
the profile in layers of thickness equal to the thickness of the cut. Plasticizers will
bond in layers until the template is created.

Figure 2. 5 FDM Modeling Methodology [10]

Advantages:
 Diverse, inexpensive materials. In principle can use materials: substances,
plastic, metal, composites and ceramics.
 High accuracy. By filling layers of material overlapping and then solidified,
the system can protect the thick initial count of material
 Saves a lot of material compared to the machining methods because of the
unmanufactured method.
 Don’t need support structure.
 High speed, faster than other layer methods because the laser does not cut the

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whole area that only sweeps in the outer perimeter. Therefore, the material is
thick and thin with the same cutting speed.
 No phase change during the fabrication process should avoid shrinkage
withdrawal of material.
 Non-toxic and environmental pollution.
Disadvantages:







The warping of details is usually the main problem of the LOM method.
The surface gloss is not high.
There is a tendency between classes
Support may be needed.
Temperature fluctuations during production can lead to poor link, poor z
direction and slow speed.

After analyzing all possible methods of RAP, we decided to apply FDM technology
in our research with some reasons as following.
2.1.5. Analysis of 3D FDM (Fused Deposition Manufacturing)
2.1.5.1. Reasons to choose FDM
FDM machines have the advantages of using a variety of materials, easy to change
material, simple forming, low cost compared to the machine used Stereo lithography
and Laser Sintering, easy to repair, are capable of producing those thin parts and large
size, no laser source, use a lot of materials and no toxic materials. In order to create
rapid prototypes that do not cost a lot of money for prototyping, FDM can provide
the best option. Compared with Stereo lithography and Laser Sintering, the FDM
method is obviously feasible to make a low-cost RAP but still afford to respond the
requirement of the rapid prototyping.
2.1.5.2. Principles of operation
Instead of lasers and materials, FDM builds by stretching hot plastic and solidifying
each layer makes the structure more solid. Construction material in the structure of a
thin stranded fiber, drawn from a roll to a motor driven by stepper motor. When the
fiber reaches the probe, it is melted by temperature then it is ejected through the
nozzle to the detailed plane. When the molten material is ejected, it is flatten by a

nozzle in such a way that the welder or painter uses the tip to spread the material. The
width of the spreading path can vary from 0.193 to 0.965 mm and is determined by
the size of the nozzle’s mouth. The spray nozzle cannot be changed during the
modeling process, so the modeling analysis must be selected before. When the molten
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