Bachelor Thesis Supervisor Ph D Hoang Tien Dat THAI NGUYEN UNIVERSITY OF TECHNOLOGY FACULTY OF INTERNATIONAL TRAINING BACHELOR THESIS DESIGN AND FABRICATE MULTIFUNCTION DESKTOP CNC MACHINE Students Su.
Bachelor Thesis Supervisor: Ph.D Hoang Tien Dat THAI NGUYEN UNIVERSITY OF TECHNOLOGY FACULTY OF INTERNATIONAL TRAINING BACHELOR THESIS DESIGN AND FABRICATE MULTIFUNCTION DESKTOP CNC MACHINE Students : Ban Phuc Hieu Student’s ID : K175905218008 Luu Van Hoang Student’s ID : K175905218010 Supervisor : Ph.D Hoang Tien Dat Thai Nguyen , 2022 This thesis has been approved by the : The Supervisor: Dr Hoang Tien Dat Signed: Date: Bachelor Thesis Supervisor: Ph.D Hoang Tien Dat Head of the Division:Ph.D Nguyen Dinh Ngoc Signed: Date: Faculty of Dean : Ph.D Nguyen Tien Hung Signed: Date: Composition of the Committee: M.Sc Le Van Nhat Thai Nguyen University of Technology Dr Nguyen Thi Quoc Dung Thai Nguyen University of Technology Dr Hoang Tien Dat Thai Nguyen University of Technology Ph.D Nguyen Dinh Ngoc Thai Nguyen University of Technology Assoc Prof Vu Ngoc Pi Thai Nguyen University of Technology Assoc Prof Nguyen Van Du Thai Nguyen University of Technology M.Sc Phan Thanh Dat Thai Nguyen University of Technology Copyright © 2022 by Luu Van Hoang & Ban Phuc Hieu All rights reserved Published by the Faculty of International Training (FIT) Thai Nguyen University of Technology Declaration of Authorship We are Luu Van Hoang and Ban Phuc Hieu, declare that this thesis titled, “Design And Fabricate Multifunction Desktop Cnc Machine” and the work presented in it is our own We confirm that: Bachelor Thesis Supervisor: Ph.D Hoang Tien Dat This work was done mainly while in candidature for a research degree at this University Where any part of this thesis has previously been submitted for a degree or any other qualification at this University or any other institution, this has been clearly stated Where we have consulted the published work of others, this is always clearly attributed Where we have quoted from the work of others, the source is always given With the exception of such quotations, this thesis is entirely our own work We have acknowledged all main sources of help Where the thesis is based on work done by ourselves jointly with others, we have made clear exactly what was done by others and what we have contributed ourself Signed: Signed: Date: Acknowledgement I would like to express my sincere thanks to those who have supported me throughout the process of completing my graduation project The successful completion of this project is the result of everyone's dedicated guidance and Bachelor Thesis Supervisor: Ph.D Hoang Tien Dat encouragement and perhaps, I am not able to complete this project without their valuable assistance This acknowledgment is taken of small gratitude in recognition of the support provided by them First of all, we would like to send heartfelt thanks to Ph.D Hoang Tien Dat, a kind and helpful supervisor, for her valuable guidance, constant encouragement, and creative suggestions on making the project I also wish to express my gratitude to Thai Nguyen University in general and all the teachers in Faculty of International Training in particular Thank you for your efforts to create a dynamic and professional learning environment with valuable knowledge as a preparation for students in future work In addition, we would like to thank all lecturers in the Advanced Program of Faculty of International Training for their guidance and the knowledge that they have equipped us throughout our entire student life at the Thai Nguyen University of Technology Furthermore, we would like to Ph.D Hoang Tien Dat for his support and suggestion for the completion of this thesis Last but never least, we are grateful to our parents and to our classmates for providing us with unfailing support and continuous encouragement throughout our years of study and through the process of researching and writing this thesis This accomplishment would never be possible without them Abstract Nowadays, We all know that CNC machines play an indispensable role in many industries They are controlled accurately by computers and used for jobs requiring high precision In many people's minds, CNC machines are huge, Bachelor Thesis Supervisor: Ph.D Hoang Tien Dat complex, and expensive industrial systems, but thanks to the rapid growth of technology, their size becomes more and more compact, that even fit on your desk and their price is more affordable CNC machine has many applications, base on the user's purpose, It may be a CNC milling machine, a 3D printer, or a laser engraver machine, etc We all know that those machines are great for our job, but at some point, they can't replace each other Although the demand for them is big, owning all the above machines is very difficult Especially for people like me It is expensive and takes up space So my idea is to design a machine that can all the functions above, share the same frame and other components, you just have to change the tool you need, and the machine is ready to use In this report, we will mainly discuss the process of design, fabrication, and operation of this machine Talking about the machine, it is a axis CNC The machine is built from many familiar components that easy to find on the market It can run direct G code from the computer or SD card The machine will run on the Marlin firmware that is quite familiar to 3D printer users, and it can work with others software such as Cura, CNCjs, Lightburn depending on your purpose It also comes with useful features such as auto bed leveling, auto Z align, Z probe for CNC, dual nozzle,… This will help your job done quickly and easier than ever Key work: All in one CNC machine,3D printer, Cura, CNC software,… Bachelor Thesis Supervisor: Ph.D Hoang Tien Dat Bachelor Thesis Supervisor: Ph.D Hoang Tien Dat Bachelor Thesis Supervisor: Ph.D Hoang Tien Dat Bachelor Thesis Supervisor: Ph.D Hoang Tien Dat Bachelor Thesis Supervisor: Ph.D Hoang Tien Dat List of Abbreviations 10 Bachelor Thesis Supervisor: Ph.D Hoang Tien Dat Figure 2: From left to right: CNC lathe and CNC milling machine – CNC plasma cutters: a machine carries a plasma torch, which is for cutting metals, involves cutting through electrically conductive materials by an accelerated jet of hot plasma Figure 3: A CNC plasma cutter - 3D printer: Include many methods such as FDM, SLA,… but we will mainly discuss about FDM - the method that my machine use This process will create a 3D model by the additive process, We can understand that the print head works a spindle, but instead of cutting the material, the material will be heated and precisely layered through the print head 15 Bachelor Thesis Supervisor: Ph.D Hoang Tien Dat Figure 4: Some 3D printer There are still many other types of CNC machines but to focus on the main purpose, we would like to not mention them 1.2.2 Number of axis The reference to axes is used to describe CNC machines which operate along multiple axis points CNC machining is the process of removing material from a work piece until the desired shape is configured These machines have at least a axes and operate along an XYZ plane: X axis (vertical), Y axis (horizontal), and a Z axis (depth) The 4th axis denotes the inclusion of an A axis (rotation around the X axis) The number of axes on a CNC machine determines the type of work it can do, the level of detail it can cut, and the work piece locations it can manipulate, the following provides a better explanation of the differences between a axis, and axis CNC machines Axis: axis machining implies that a work piece is processed in the same way it would be with a axis machine, but has an additional rotary movement around the X axis, which is named the A axis This rotation allows the work piece to be cut around the B axis This method is beneficial when holes or cuts need to be made on the sides of a work piece The addition of a fourth axis (A axis) allows a work piece to be 16 Bachelor Thesis Supervisor: Ph.D Hoang Tien Dat automatically flipped over, so the machine can remove material from both sides axis machining is multifunctional and can be used for: Intermittent cutting Continuous cutting Engraving curved surfaces Axis: Axis machining implies that a work piece can be automatically manipulated from five sides at one time In addition to automatic movements along the X, Y, and Z axes, axis CNC machines can select two of the three rotational axes (A,B,C) to use The A, B, and C axes perform a 180° rotation around the X, Y, and Z axes, correspondingly This type of machining is used in the automobile, aerospace, and boating industries Application is commonly favored for extremely complex components that are solid and would otherwise have to be cast axis machining requires greater CNC programming preparation time to accommodate complex rotatory movement, but allows one work piece to be worked on all five sides during one operation axis machining is 17 Bachelor Thesis Supervisor: Ph.D Hoang Tien Dat beneficial when components require a great deal of intricacy and quick precision This includes: Increased productivity Higher quality finishes Cutting intricate details Machining complex shapes Figure 6: Illustration for a axis CNC machine 1.2.3 Frame In our opinion, for common axis CNC machine, there are two main types of design: Fixed frame-mobile bed and movable frame- fixed bed.To choose for yourself a suitable frame style, you can review some factors such as: required cutting area, machine size requirements,materials and tools,… and one of the most important factor - budget, this will determine what components you can equip for your machine Normally, when work with sheet material - not demand too much height but require a large working area, movable gantry machines is a great choice for you These machines are quite optimal in tern of size as they can make the most of their length and width but this is a trade-off among height, rigid and working area This type of design is often used for CNC router, CNC plasma, and CNC laser If you have work on hard materials and machine’s stiffness is a problem, 18 Bachelor Thesis Supervisor: Ph.D Hoang Tien Dat stationary gantry is recommenced This type of design is more prominent in the hobby CNC router community than the mobile gantry design However, there are reasons for choosing the mobile bed design type The mobile bed design is typically found on smaller CNC machines such as 3D printers ( Prusa I3 and tons of its clones) or small CNC engraving machines For this size machine, the mobile bed design works well The biggest advantage of this design is that creating a sturdy gantry that will not flex under load is much easier With a mobile gantry, youmust take into consideration the weight of the gantry itself and the size, in regards to the linear bearings on the Y axis With the mobile bed design, the gantry itself does not move, therefore you have more breathing room in regards to the weight, size, and structural design There are disadvantages with this type of design as well As the length of the Y axis increases the mobile bed design become less efficient The following figure will show you two type of design above and with each of type of design there will be many others variations You need to decide which design will fit your needs best Figure : Left to right: a fixed frame with the bed moves along Y axis; a machine with fixed bed, X and Z axis move along Y axis 1.4 GENENRAL OF CNC MACHINE 1.4.1 Basic Concept A CNC system can be described in terms of three major elements, shown infollowing figure, include: hardware, software and information 19 Bachelor Thesis Supervisor: Ph.D Hoang Tien Dat Figure 8: Basic concept of CNC machine Hardware: A Hardware includes microprocessors that affect control system functions and peripheral devices for data communication, machine tool status monitoring, and machine tool interfacing Software: The software includes programs that are performed by system microprocessors and there are different types of software associated with CNC Information: Information about the dynamic characteristics of the machine and much other information related to the process When any of these deceptive components fail, the diagnostics subsystem will automatically separate the faulty component from the system and activate the unnecessary component in place of the damaged one so that the newly installed component can perform its task 1.4.2 Basic Part of the CNC Machine The main parts of the CNC machine are: Input devices, machine control unit (MCU), machine tool, driving system, feedback system, display Here are Illustration figure and relative information 20 Bachelor Thesis Supervisor: Ph.D Hoang Tien Dat Figure : Basic components of a CNC system Input Devices: These are devices that are used to input the part program into a CNC machine Machine Control Unit (MCU): Performs all the control functions of the CNC machine, there are various tasks performed by MCU that are It reads the coded instructions given in it Machine control unit decodes the coded instruction This axis implements interpolation (linear, circular and helical) to generate motion commands Machine control unit feeds the axis motion command to the amplifier circuit to drive the axis mechanism It takes a feedback signal of position and speed for each drive axis It implements the auxiliary control functions such as coolant or spindle on/off and tool change The below figure is my machine controller, using Mach3 USB Figure 10 : Wiring diagram of Mach3 21 Bachelor Thesis Supervisor: Ph.D Hoang Tien Dat Machine Tool: A CNC machine tool always has a sliding table and a spindle to control the position and speed The table of the machine is controlled in the X and Y-axis direction and the spindle is controlled in the Z-axis direction Driving System: The driving system of a CNC machine include of a driver circuit, motors, and guiding mechanism The MCU sends the signals of position and speed of each axis to the driver circuits The driver circuits actuate the motors via control signals, and the motors move the guiding mechanisms to given position Figure 11 below is an illustration of a driving system using a linear rail and a ball screw Figure 11: Example of a Z axis Feedback System: The feedback system has transducers that act as sensors It is also called a measuring system It consists of position and speed transducers that continuously monitor the position and speed of the 22 Bachelor Thesis Supervisor: Ph.D Hoang Tien Dat cutting tool located at any given moment The MCU receives signals from transducers and it uses the difference in reference signals and feedback signals to generate control signals to correct position and speed errors Here is example figure : Figure 12: Limit switch and motor encoder Display Unit: The monitor is employed to display programs, commands and other useful data of the CNC machine 1.4.3 Working principle In the numerical control system, the position of the tool is determined by a set of instructions called the part program Position control is performed by an openloop or closed-loop system In an open-loop system, communication takes place only in one direction: from the controller to the motor In a closed-loop system, feedback is provided to the controller so that the controller can correct position, velocity, and acceleration errors that may arise due to changes in load or temperature Open loop systems are generally cheaper but less accurate Stepper motors can be used in both types of systems, while servos can only be used in closed systems The below figure will help us to understand the CNC machine working principle more easy 23 Bachelor Thesis Supervisor: Ph.D Hoang Tien Dat Figure 13: Example for CNC system working principle First, the part program is entered into the MCU of the CNC The MCU processes all the data and according to the program prepared, it prepares all the motion commands and gives them to the driving system The drive system acts as motion commands sent by the MCU The drive system manages the motion and velocity of the machine tool The feedback system records the position and velocity measurements of the machine tool and gives a feedback signal to the MCU In the MCU, the feedback signals are compared with reference signals and if errors occur, it corrects it and sends new signals to the machine tool to be corrected The display unit is used to see all the programs, commands, and other data It works like the eye of the machine 1.4.4 Advantage and Disadvantage of CNC machine Advantages of CNC Machine: 24 Bachelor Thesis Supervisor: Ph.D Hoang Tien Dat CNC machine can produce jobs with highest accuracy and precision than any other manual machine It eliminates human errors It can be operated for 24 hours of a day Higher flexibility also The parts manufactured by it have the same accuracy There is no variety in parts manufactured by CNC machines A highly skilled operator is not needed to run a CNC machine A semi-skilled operator can also operate accurately and more precisely Operators can easily make changes and improvements and reduce the delay time and Reduce inspection cost It has the capability to produce a complex design with high accuracy in minimum possible time with minimum wastage Modern design software allows the designer to emulate the creator of his idea And this removes the need for making a prototype or model a saves time and money Fewer workers are required to operate a CNC machine and save labour cost It is suitable for batch production It requires less space for its operations More operational safety 25 ... works like the eye of the machine 1 .4. 4 Advantage and Disadvantage of CNC machine Advantages of CNC Machine: 24 Bachelor Thesis Supervisor: Ph.D Hoang Tien Dat CNC machine can produce jobs with... along Y axis; a machine with fixed bed, X and Z axis move along Y axis 1 .4 GENENRAL OF CNC MACHINE 1 .4. 1 Basic Concept A CNC system can be described in terms of three major elements, shown infollowing... base on the function of each machine such as CNC milling machines, CNC lathes, CNC plasma cutters,… Here are some short definitions with pictures – CNC milling machines: used to create shapes,