Design and implementation of a multicolor 3d printer

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

MINISTRY OF EDUCATION AND TRAINING

HCMC UNIVERSITY OF TECHNOLOGY AND EDUCATION

GRADUATION THESIS MECHATRONIC ENGINEERING TECHNOLOGY

DESIGN AND IMPLEMENTATION OF

A MULTICOLOR 3D PRINTER

S K L 0 0 5 3 6 6

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

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)

SOCIALIST REPUBLIC OF VIETNAM Independence - Freedom - Happiness

***

Ho Chi Minh City, May 31 th 2017 MISSION OF THESIS

Student’s name: Pham Xuan Chien Student’s ID: 13146023

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

SOCIALIST REPUBLIC OF VIETNAM Independence - Freedom - Happiness

***

ADVISOR’S COMMENT

Student’s name: Pham Xuan Chien Student’s ID: 13146023

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:

2 Advantages:

3 Improvement points:

4 Thesis defense approval: Yes  No 

5 Evaluation remark:

6 Grade: (in word: )

Ho Chi Minh City, July 2017

Advisor

(Name, signature)

SOCIALIST REPUBLIC OF VIETNAM Independence - Freedom - Happiness

***

REVIEWER’S COMMENT

Student’s name: Pham Xuan Chien Student’s ID: 13146023

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)

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

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

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

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

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

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

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

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

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 3Dprinting 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

1.4.2 Goal of the study

+ 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

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

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

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

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]

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

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

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

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

 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

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

 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]

 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

 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]

 Don’t need support structure

 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 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

metal is flatten it cools about 1/10 second and froze When a layer is covered, the railing surface moves downward from a normal thin layer of 0.178 to 0.356 mm and the process is repeated As with Stereo lithography and Laser Sintering, the FDM system reads STL files follow the standard input of all rapid prototyping methods File STL consists of a closed triangular mesh created from the plane of the CAD model The software in the FDM system will cut the STL file into a series of cross-sections that are mapped by the nozzle In order to produce precise details, it controls the critical temperature of the chamber and the formation of the details The temperature of the chamber must be kept below the melting point of the material so that only a small amount of heat is sufficient to melt the stranded ejecting hair and form details that do not sink or deform The details must be kept refrigerated so that the melted material hardens and binds together

2.1.5.3 Speed

Because FDM systems create details by extending the narrowing of material particles, large, blocky or thick-walled components, it takes a long time to complete Small parts or thin walls can be created quickly The time required to fabricate details depends on the FDM freezing rate (determined by the size of the nozzle), the height

of the part (number of layers), the horizontal dimension of the part The amount and complexity of the additive required (additive for each layer creates a separate step)

2.1.5.3 Choice of use

The FDM details are harder and more durable than the production details by Stereo lithography but they have poor surface quality and are not sharp ABS materials, polycarbonate, poly-phenyl-sulfone are heat-resistant, mechanical, and moisture-resistant, so FDM details can be used for a wide variety of specialized, auxiliary models, depends on each application FDM details are not pitted and do not need to infiltrate me twice Unlike stereo lithography or Laser sintering, FDM machines can

be used in office environments and FDM materials do not need much special handling Many FDM systems are cheaper than Stereo lithography and Laser sintering For companies that want to produce durable and accurate samples for the firm FDM may be a good choice

2.2 Multicolor printing solutions

2.2.1 Using multi nozzle

This is the earliest method It uses multi extruder like dual extrude or quad extruder

to print more color

Figure 2 6 Dual nozzles

Advantages:

Can print 2 or more colors depend on how much nozzles you use

Disadvantages:

 The printable area shrinks

 Long print time Process of color change is slow

 Increasing the weight on the extruder carriage Twice as much wiring Twice

as many things that can break

 The Z-Calibration is difficult

 The calibration in X-Y axes is even harder

 The retraction does not always work on 100% so when the extruders moves, filament leftovers get stuck on the print

Figure 2 7 Filament stuck on the print [2]

2.2.2 Palette method [4]

The Palette filament feeding system is the product of Mosaic Manufacturing It can

be attached to almost any FDM 3D printer and with it you can print objects in multiple colors or multiple material properties There have been many systems that promised fluid color changes and color mixing but most of them were based on new specialized extruders and in-nozzle mixing which made real application complex and heavy The Palette approaches this problem differently and comes in the form of a separate box where all the filament mixing magic happens

Figure 2 8 Palette printing

Printer loaded with up to 4 filaments and palette handles the rest: cuts, calculates and creates a singular custom strand made of multiple filaments

Figure 2 9 Structure of Palette [4]

Advantages:

The integration with the printer’s existing extruder set-up With delta-printer, in order

to print nicely it typically requires the lightest extruder assembly possible To add five nozzles to the end of a delta would have terrible results, cause vibrate and print terribly with lots of ringing, and eventually, destroy itself in the process Mosaic simply sits in front of the extruder-cold end, where the filament usually comes in, and does its thing

Figure 2 10 Product of Palette [4]

Figure 2 11 Diamond Hotend [7]

 Minimize costs due to the need to equip multiple print heads

 The Diamond also has the ability to mix colors or materials together to create new combinations, allowing more than three colors to be printed

Disadvantages:

 Not work perfectly 100%, sometimes filament gets stuck in nozzle

 Only works with Slicer, Cura can’t use to print multiple color

 There is no mixing chamber as such When filaments are “mixed” they come out of the nozzle like stripy toothpaste So the color is biased towards each input This effect can be partly negated by using translucent filament or it can

be exploited for decorative purposes

2.2.4 Multicolor filament [11]

UniCoFil is specialized on multi-color filament Multi-color filaments have been developed for multi-color prints using a single extruder (3D printer with one nozzle) This makes multi-color printing as easy as single-color prints Because there are several colors on one spool consecutively, the prints will consist of several colors automatically

Figure 2 12 Multicolor filament and product [11]

Advantages:

 Give your 3D prints a unique design Each print will be one of a kind

 Highest quality filament

 Can be used in 3D printers without heated bed as well

Disadvantages:

 Can’t control color follow your desire

 This product is not popular, hard to find and buy

 Price is double compare to normal filament

2.3 The effect of temperature on the operation of the printing [8]

A good nozzle is to overcome the jamming of the material, and the amount of material flow out evenly The main cause is the effect of heat

Figure 2 13 Compare the temperature distribution between nozzles have good heat sink and don’t

have good heat sink [8]

If there is no good heat dissipation, the temperature at the top and the baking section

is almost the same As shown above, if the heating element temperature is from 213

to 240 degrees, the top of the print head about 196-200 degrees High temperature is required to warm up the print head, and the print media is melt When not brought to the heating element, causing material jam or high friction between the print material and the material pipe

Figure 2 14 Material jam at the location exposed two heat zones [6]

At the transition area between the heating and heat dissipation will appear phenomenon that material is enlarged because the temperature is close to the melting temperature of the material, causing large friction to trap material To overcome this phenomenon, a heat-resistant PTFE resin casing is provided at the contact area Thanks to the heat and friction are low in this kind of material so there will be no material jam

Figure 2 15 Add material at the heat transfer location [8]

CHAPTER 3: DESIGN AND ANALYSIS 3.1 Mechanical design

3.1.1 The structure of 3D printer [3]

3.1.1.1 Cartesian structure

The 3D printers move the plastic extrusion by the X, Y, Z directions in the Cartesian coordinates Typical representatives of the open-source Cartesian 3D printer series are the Prusa i3 or Mendel

Advantages:

- Assemble, align and maintain easily

- Large blur source community

- Suitable for beginners to get acquainted with 3D printing technology

Disadvantages:

- The volume of the mechanism is large, so the speed is not high and noise

- When operating the machine often shake and thus reduce the accuracy

- Large horizontal size, often limited to the height of the print

Figure 3 1 Cartesian structure [3]

3.1.1.2 Delta structure

The 3D printers moving plastic extrusions according to the principle of the delta robot (parallel robot) Typical representation of Delta's open source printers is the Delta robot 3D printer (Kossel)

Advantages:

 The volume of small moving parts and moving parts along the vertical axis

 Quiet operation, low vibration, high speed and accuracy

 Can print high-resolution prints

 The heat table (place of print) does not move during printing so the print media

is held firmer

 Frame sure

Disadvantages:

 Assembly, alignment is a bit complicated (but once mastered it is very easy)

 Height of the machine (usually up to 60-70 cm)

 Usually a little more expensive than Cartesian machines

Figure 3 2 Delta structure [3]

 Machine operation is less shaken like Cartesian

 Print size may be large

Disadvantages:

 Inertia of large heat table

 Print speed is not high

 Assembly and alignment difficult

 High price

3.1.1.3 Conclusion

After comparing, we decided to choose Cartesian structure with Prusa I3 model because

 Installation, alignment and easy maintenance

 Have a large open source systems

 Suitable for beginners get acquainted the 3D printing technology

Figure 3 3 Polar structure [3]