GOVERNMENT ENGINEERING COLLEGE IDUKKI

PAINAVU 685 603

2D ROBOTIC PLOTTER

(CNC MODEL)

MAIN PROJECT REPORT

Submitted By

ALEENA BOBAN (12004725)

ANANDKRISHNAN V S (12004728)

SABANA UNNIKRISHNAN (12004768)

SHIBIL P B (12004772)

In partial fulfilment

of

BACHELOR OF TECHNOLOGY

ELECTRONICS AND COMMUNICATION

ENGINEERING

MAHATMA GANDHI UNIVERSITY

MAY 2016

GOVERNMENT ENGINEERING COLLEGEIDUKKI

PAINAVU 685 603

DEPARTMENT OF

ELECTRONICS AND COMMUNICATIONENGINEERING

BONAFIDE CERTIFICATE

This is to certify that the project report entitled 2D ROBOTIC PLOTTER (CNC MODEL)

is a bonafide record of the paper presented by ALEENA BOBAN (Reg.no:12004725),

ANANDKRISHNAN V S (Reg. no:12004728),SABANA UNNIKRISHNAN (Reg

.no:12004768), SHIBIL P B (Reg.no:12004772) during their final semester in partial

fulfillment of the requirement for the award of B-Tech Degree in Electronics & Communi-

cation Engineering of Mahatma Gandhi University, Kottayam, Kerala.

PROJECT GUIDE PROJECT COORDINATOR

Linu Shine Dr.S Santhosh Kumar

Asst.Prof ECE Asso.Prof ECE

HEAD OF THE DEPARTMENT

DECLARATION

I hereby declare that the project titled 2D ROBOTIC PLOTTER (CNC MODEL) being

submitted in partial fulfillment for the award of B.Tech degree is the original work carried out

by me. It has not formed the part of any other thesis submitted for award of any degree or

diploma, either in this or any other University.

(Signature of the Candidate)

NAME:

Register No:

3

ACKNOWLEDGEMNT

We give all honor and praise to the LORD who gave us wisdom and enabled us to complete

this project successfully.

We express our heartfelt thanks to Dr. Asok Kumar N, Government Engineering College,

Idukki for granting us permission to do the project.

We express our sincere thanks to our head of the department Prof.Jalaja M J and project guide

Ms Linu Shine and project coordinator Dr.S Santhosh Kumar for their valuable advice and

guidance.

We also express our gratitude and thanks to all our teachers and other faculty members of the

department of Electronics and Communication, Government Engineering College, Idukki for

their sincere and friendly cooperation in completing this project.

We are extremely grateful to our parents for their silent prayer.

4

ABSTRACT

2D Robotic Plotter is an embedded system that works based on the principle Computer

Numerical Control.Robotic 2D Plotter basically works with two stepper motors and a

servo motor, wherein the robot plots the input given from the computer on the drawing

board using ATMEGA 328p microcontroller on a open-source physical computing platform

Arduino. The Robotic 2D plotter has a two axis control and a special mechanism to raise and

lower the pen. Each axis is powered and driven by using an Arduino compactable driver

L293D. Pen control is achieved using a servo.The X and Y axis mainly consists of step-

per motors taken from CD-drives.The software used for programming the Arduino board are

namely Inkscape(0.48.5),Processing (3.0.2),CAMOTICS,Arduino IDE.The correct and efficient

arrangement and proper use of the programs along with the circuit makes up an efficient 2D

Robotic Plotter (CNC).

5

Contents

1 Introduction 9

1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

1.2 Computer Numerical Control (CNC) . . . . . . . . . . . . . . . . . . . . . . . . 9

1.3 2D Robotic Plotter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

1.4 Aim of the Thesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

1.5 Literature Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

1.6 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

1.7 Organisation of the Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

1.8 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

2 Project Description 15

2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

2.2 Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

2.3 Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

2.4 Industrial Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

2.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

3 Software 17

3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

3.2 Inkscape (0.48.5) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

3.2.1 Scalar Vector Graphics(SVG) . . . . . . . . . . . . . . . . . . . . . . . . 18

3.2.2 Inkscape Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

3.2.3 Inkscape Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

3.2.4 Generating gcode files using inkscape . . . . . . . . . . . . . . . . . . . . 21

3.3 CAMotics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

3.4 Arduino IDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

3.5 Processing 3.0.2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

3.5.1 Sketching with Processing . . . . . . . . . . . . . . . . . . . . . . . . . . 25

3.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

6

4 Hardware 27

4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

4.2 Arduino UNO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

4.3 Adafruit L293D Motor Shield . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

4.4 Servo Motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

4.4.1 Working principle of Servo Motors. . . . . . . . . . . . . . . . . . . . . . 30

4.4.2 Controlling Servo Motor . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

4.5 Stepper Motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

4.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

5 Industrial Design 34

5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

5.2 X-Y Direction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

5.3 Stand holding the whole . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

5.4 Pen Setup (Z-axis) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

5.5 Final Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

5.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

6 Overall View and Setup of the Project 37

6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

6.2 Steps Involved in the Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

6.3 Result . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

6.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

7 Applications 40

8 Conclusion and Future Aspects 41

Appendices 44

.1 Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

.2 Arduino UNO Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

.3 L293D Specifications (Motor Driver IC) . . . . . . . . . . . . . . . . . . . . . . . 58

7

List of Figures

1.1 Intersecting lines form right angles and establish the zero point (Allen-Bradley) 10

1.2 The three-dimensional coordinate planes (axes) used in CNC. (The Superior

Electric Company) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

1.3 The quadrants formed when the X and Y axes cross are used to accurately located 11

3.1 Inkscape Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

3.2 Processing Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

4.1 Arduino UNO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

4.2 Adafruit L293D Motor Shield . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

4.3 Servo Motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

4.4 Controlling of Servo Motor (PWM) . . . . . . . . . . . . . . . . . . . . . . . . . 32

4.5 Stepper Motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

5.1 Lens Frame in CD Drive (Containing Stepper Motor) . . . . . . . . . . . . . . . 35

5.2 CD Drive Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

5.3 Pensetup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

5.4 View 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

5.5 View 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

6.1 Main Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

6.2 Plotted Output Image . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

.31 Pin Out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

.32 Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

.33 Electrical Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

8

Chapter 1

Introduction

1.1 Introduction

CNC stands for Computer Numeric Control and typically refers to a machine whose operation

is controlled by a computer. The most common usage of CNC, and the one relevant to us, is

the name given to devices that, under computer control are able to cut, etch, mill, engrave,

build, turn and otherwise perform manufacturing operations on various materials. Typically,

a CNC machine has the ability to move a cutting or 3D printing head in 2 to 6 axes, meaning

that it can position that tool head at a precise point in or on the material to create the cut

or operation desired at that point. By moving the head through multiple points, the cutting

head can cut or sculpt the design represented by a data stream of positioning points being sent

by the PC. By controlling a CNC machine through a PC it is possible for the user to design

a product on-screen, convert it to CNC-readable code and then send that data to the CNC

machine for it to produce a physical copy of the item designed.

1.2 Computer Numerical Control (CNC)

The term numerical control is a widely accepted and commonly used term in the machine tool

industry. Numerical control (NC) enables an operator to communicate with machine tools

through a series of numbers and symbols.

NC which quickly became Computer Numerical Control (CNC) has brought tremendous changes

to the metalworking industry. New machine tools in CNC have enabled industry to consis-

tently produce parts to accuracies undreamed of only a few years ago. The same part can be

reproduced to the same degree of accuracy any number of times if the CNC program has been

properly prepared and the computer properly programmed.

The operating commands which control the machine tool are executed automatically with

9

Figure 1.1: Intersecting lines form right an-

gles and establish the zero point (Allen-

Bradley)

Figure 1.2: The three-dimensional coordi-

nate planes (axes) used in CNC. (The Su-

perior Electric Company)

amazing speed, accuracy, efficiency, and repeatability. The ever-increasing use of CNC in in-

dustry has created a need for personnel who are knowledgeable about and capable of preparing

the programs which guide the machine tools to produce parts to the required shape and accu-

racy.

Cartesian Coordinate System

Almost everything that can be produced on a conventional machine tool can be produced

on a computer numerical control machine tool, with its many advantages. The machine tool

movements used in producing a product are of two basic types: pointto- point (straight-line

movements) and continuous path (contouring movements).

The Cartesian, or rectangular, coordinate system was devised by the French mathematician

and philosopher Rene’ Descartes. With this system, any specific point can be described in

mathematical terms from any other point along three perpendicular axes. This concept fits

machine tools perfectly since their construction is generally based on three axes of motion (X,

Y, Z) plus an axis of rotation. On a plain vertical milling machine, the X axis is the horizontal

movement (right or left) of the table, the Y axis is the table cross movement (toward or away

from the column), and the Z axis is the vertical movement of the knee or the spindle. CNC

systems rely heavily on the use of rectangular coordinates because the programmer can locate

every point on a job precisely.

The three-dimensional coordinate planes are shown in Fig. 1.2. The X and Y planes (axes)

are horizontal and represent horizontal machine table motions. The Z plane or axis represents

10

the vertical tool motion. The plus (+) and minus (-) signs indicate the direction from the zero

point (origin) along the axis of movement. The four quadrants formed when the XY axes cross

are numbered in a counterclockwise direction (Fig. 1.3). All positions located in quadrant 1

would be positive (X+) and positive (Y+). In the second quadrant, all positions would be

negative X (X-) and positive (Y+). In the third quadrant, all locations would be negative X

(X-) and negative (Y-). In the fourth quadrant, all locations would be positive X (X+) and

negative Y (Y-). In Fig. 1.3 , point A would be 2 units to the right of the Y axis and 2 units

Figure 1.3: The quadrants formed when the X and Y axes cross are used to accurately located

above the X axis. Assume that each unit equals 1.000. The location of point A would be X +

2.000 and Y + 2.000. For point B, the location would be X + 1.000 and Y - 2.000. In CNC

programming it is not necessary to indicate plus (+) values since these are assumed. However,

the minus (-) values must be indicated. For example, the locations of both A and B would be

indicated as follows:

A X2.000 Y2.000

B X1.000 Y-2.000

11

1.3 2D Robotic Plotter

Robotics is the branch of technology that deals with the design, construction, operation, and

application of robots, as well as computer systems for their control, sensory feedback, and

information processing. The design of a given robotic system will often incorporate principles

of mechanical engineering, electronic engineering and computer science (particularly artificial

intelligence).The term ’robotics’ was coined by Isaac Asimov in his science fiction short story

called ’Liar’. Robot is an electro-mechanical machine which is guided by a electronic circuitry

or computer program to perform various tasks. A robotic arm is a robotic manipulator, usually

programmable, with functions similar to that of human arm. Robotic 2D Plotter is a plotter

that offers the fastest way to efficiently produce very large drawings. Pen plotters will be able

to print by moving a pen or other writing device across the surface of a piece of paper. This

means that plotters are vector graphics devices, rather than raster graphics. Pen plotters can

draw complex line art, including text, but do so slowly because of the mechanical movement

of the writing device such as pen.

1.4 Aim of the Thesis

Aim of the thesis is to set up a 2D Robotic Plotter for the following constraints:

• A general idea of CNC Models.

• Generating GCODE. Integrating the diffrent softwares along with the hardware setup.

1.5 Literature Review

1. Jae Wook Jeon and Young Youl Ha, A Generalized Approach for the Acceleration and

Deceleration of Industrial Robots and CNC Machine Tools, IEEE Transactions on Indus-

trial Electronics, Vol. 47, No. 1, February 2000, pp. 133-139

Many techniques for the acceleration and deceleration of industrial robots and computer

numerical control (CNC) machine tools have been proposed in order to make industrial

robots and CNC machine tools perform given tasks efficiently. Although the techniques

selecting polynomial functions can generate various acceleration and deceleration charac-

teristics, the major problem is the computational load. The digital convolution techniques

are more efficient than the techniques selecting polynomial functions. However, neither

velocity profiles of which the deceleration characteristics is independent from the accel-

eration characteristics nor those of which the acceleration interval is different from the

deceleration interval can be generated by the digital convolution techniques. This paper

proposes a generalized approach for generating velocity profiles that cannot be gener-

ated by the digital convolution techniques. According to the desired characteristics of

12

acceleration and deceleration, each set of coefficients is calculated and is stored. Given

a moving distance, and acceleration and deceleration intervals, a velocity profile having

the desired characteristics of acceleration and deceleration can be efficiently generated

by using these coefficients. Several velocity profiles generated by the proposed technique

will be applied to one single-axis control system.

2. Allen G. Morinec, Power Quality Considerations for CNC Machines: Grounding, IEEE

Transactions on Industrial Electronics, Vol. 38, No. 1, January/February 2002, pp. 3-11.

Computer numerical control (CNC) machines are used to shape metal parts by milling,

boring, cutting, drilling, and grinding. A CNC machine generally consists of a computer-

controlled servo-amplifier, servo-motors, spindle motor, and various tooling. The machine

can be programmed to shape a part by use of a front control panel. More sophisticated

models allow a computer-aided design drawing to be uploaded to the machine. The

electronic components within a CNC machine are particularly sensitive to the ground-

ing techniques used in the electrical supply to the machine. Malfunction, degradation,

and damage to the electronics can often be traced to supplemental ground rods and

lightning strikes to earth. Production downtime, product loss, and expensive repair bills

result.With the wide-spread use of CNC machines across the world, these problems have

become a significant financial concern to many CNC machine users and their electric

utility companies. This paper begins with a brief explanation of the fundamentals of

service and equipment grounding. The basic design of CNC machines is also explained.

Based on a survey of several CNC machine representatives, the paper will explore the

common grounding techniques recommended by many CNC machine tool builders with

particular emphasis on the ground-rod problem. In addition, several actual case studies

that support the ground-rod problem will be described. Finally, a recommended power-

ing and grounding practice is presented to help eliminate power quality related operating

problems with CNC machines while maintaining the safety requirements of electrical

codes.

3. .Venkatram Ramachandran, Evaluation of Performance Criteria of CNC Machine Tool

Drive System, IEEE Transactions on Industrial Electronics, Vol. 45, No. 3, June 1998,

pp. 462-468.

The stability, steady-state error analysis, damping factor, and setting time of discrete

data drives for computer numerical control (CNC) machine tools are analyzed to obtain

the necessary information for the design of a practical system. The stability of the drive

is reviewed using Jury’s test and the Mitrovic criterion. The variation of damping factor

and settling time with respect to system parameters are presented based on the Mitrovic

criterion.

13

1.6 Motivation

Computer Numeric Control (CNC) refers to a wide variety of machines which are controlled

electronically and have many uses, including milling, drawing, extruding, cutting, and lathing.

CNC machines are really expensive. They are widely used in the fabrication of both electronic

and mechanical parts of large machines .So our group has decided to do a model to know about

theoretical and practical knowledge about this concept [2D Robotic Plotter].

1.7 Organisation of the Project

The report is organised as follows:

Abstract

Table of Contents

List of Figures

Chapter 1 : Introduction

Chapter 2 : Project Description

Chapter 3 : Software Description

Chapter 4 : Hardware Description

Chapter 5 : Mechanical Setup

Chapter 6 : Conclusion

References

Appendix

1.8 Conclusion

In this chapter,brief introduction of the project,literature review, motivation and organization

of the project has been prensented.

14

Chapter 2

Project Description

2.1 Introduction

The three main sections of Robotic 2D Plotter:

• Hardware

• Software

• Industrial Design

2.2 Hardware

Electronic hardware consists of interconnected electronic components which perform analog

or logic operations on received and locally stored information to produce as output or store

resulting new information or to provide control for output actuator mechanisms. Electronic

hardware can range from individual chips/circuits to distributed information processing sys-

tems. Well designed electronic hardware is composed of hierarchies of functional modules

which inter-communicate via precisely defined interfaces The XY-plotter consists of two axes

operating orthogonally to each other. Each axis includes a CD drive system that is driven by

an appropriate means. Additionally, a third axis, with limited motion capability is used to

actuate the write head.

2.3 Software

Computer software, or simply software, is that part of a computer system that consists of

encoded information or computer instructions, in contrast to the physical hardware from which

the system is built.The softwares used in this project comes under open source.Open-source

software (OSS) is computer software with its source code made available with a license in which

the copyright holder provides the rights to study, change, and distribute the software to anyone

15

and for any purpose. Open-source software may be developed in a collaborative public manner.

Open-source software is the most prominent example of open-source development.

2.4 Industrial Design

Industrial design is a process of design applied to products that are to be manufactured through

techniques of mass production. Its key characteristic is that design is separated from manu-

facture: the creative act of determining and defining a product’s form takes place in advance

of the physical act of making a product, which consists purely of repeated, often automated,

replication.The mechanical part is taken fully from CD-drive.

2.5 Conclusion

In this chapter a brief idea of the main three sections,software,hardware and industrial design

are discussed.

16

Chapter 3

Software

3.1 Introduction

Engineering as a discipline often requires more integration than large amounts of original devel-

opment. In a typical project, writing new code presents significant challenges, and the number

of features shared between projects means that it is possible to create shared components which

implement common features. A library or an existing module allows the use of a well developed

and tested component, which saves significant resources in the implementation of the project.

The drawback of components is the need to integrate various potentially conflicting interfaces,

and the need to understand a complex system in order to effectively use the component.

Components can be purchased, or may be freely available, as in the case of Open Source soft-

ware. Open Source also provides the opportunity to contribute new features and bug fixes back

in to the community. The programs and tools we chose for this project are all open source,

and use international standards, which allowed to rapidly develop the features needed.

The project software system consists of:

1. Inkscape (Version 0.48.5).

2. CAMotics.

3. Arduino IDE.

4. Processing 3.0.2.

3.2 Inkscape (0.48.5)

There are two basic types of graphic images: bitmap (or raster) images and vector images.

In the first case, the image is defined in terms of rows and columns of individual pixels, each

with its own color. In the second case, the image is defined in terms of lines, both straight and

17

curved. A single straight line is described in terms of its two end points.

The difference in these types of graphic images becomes readily apparent when a drawing is

enlarged. The same line is shown on the left and right. On the left it is displayed as a bitmap

image, while on the right it is displayed as a vector. In both cases, the line has been scaled up

by a factor of four from its nominal size.

When the bitmap resolution of a drawing matches the display resolution, the objects in the

drawing look smooth. The same drawing, but defined as a bitmap image on the left and a

vector image on the right. If the output device has the same resolution as the bitmap image,

there is little difference between the appearance of the two images.

If the bitmap resolution is significantly less than the display resolution, the display will show

jagged lines. The head of the gentleman in the above drawings has been scaled up by a factor

of five. Now one can see a difference in the quality of the bitmap drawing (left) and the vector

drawing (right). Note that the bitmap image uses anti-aliasing, a method of using grayscale to

attempt to smooth the drawing.

All output devices, with few exceptions, use a raster or bitmap image to display graphics. The

real difference between drawing with bitmap graphics and vector graphics is the point at which

the image is converted into a bitmap. In the case of vector graphics, this conversion is done at

the very last step before display, ensuring that the final image matches exactly the resolution

of the output device.

3.2.1 Scalar Vector Graphics(SVG)

SVG stands for Scalable Vector Graphics. Scalable refers to the notion that a drawing can

be scaled to an arbitrary size without losing detail. Scalable also refers to the idea that a

drawing can be composed of an unlimited number of smaller parts, parts that can be reused

many times. The SVG standard is directed toward a complete description of two-dimensional

graphics, including animation in an XML (eXtensible Markup Language) format. XML is an

open standard for describing a document in a way that can be easily extended and is resistant

to future changes in the document specification. A drawing saved in one version of SVG by one

version of a drawing program should be viewable, to the full extent possible, by any previous

or future version of any drawing program that adheres to the SVG standard. If a program

doesn’t support something in the SVG standard, it should just skip over any part of a drawing

that uses it, rendering the rest correctly.

SVG files are small, and drawings described by the standard adapt well to different presenta-

tion methods. This has led to great interest in the standard. Support is included in many web

browsers (Firefox, Chrome, Opera, Safari, and Internet Explorer from version 9), or is avail-

18

able through plug-ins (e.g., [Adobe [http://www.adobe.com/svg/viewer/install/, Ssrc SVG

[http://www.savarese.com/software/svgplugin/],and Google [http://www.google.com/chrome

frame]). Over a dozen companies including Apple (iPhone), Blackberry, LG, Motorola, Nokia,

Samsung, and Sony Ericsson produce mobile phones that utilize a subset of the full SVG stan-

dard (SVG Tiny) that has been tailored for devices with limited resources.

Inkscape is a free and open-source vector graphics editor; it can be used to create or edit

vector graphics such as illustrations, diagrams, line arts, charts, logos and complex paint-

ings. Inkscape’s primary vector graphics format is Scalable Vector Graphics (SVG) version

1.1. While Inkscape can import and export several formats, all editing workflow inevitably

occur within the guidelines of the SVG format.

Inkscape can render primitive vector shapes (e.g. rectangles, ellipses, polygons, arcs, spirals,

stars and isometric boxes), text and regions containing raster graphics. It also supports image

tracing, enabling the editor to create vector graphics from photos and other raster sources.

Created shapes can be subjected to further transformations, such as moving, rotating, scaling

and skewing. These objects may be filled with solid colors, patterns, radiant or linear color

gradient, their borders stroked or their transparency changed.

Inkscape SVG-based vector drawing program is useful for drawing:

• Illustrations for the Web.

• Graphics for mobile phones.

• Simple line drawings.

• Cartoons.

• Complex works of art.

• Figures for articles and books.

• Organization charts.

The file format that Inkscape uses is compact and quickly transmittable over the Internet. Yet

it is powerful and can describe complex drawings that are scalable to any size. Support for the

format has been added to web browsers and is already included in many mobile phones.

Inkscape supports the drawing of regular shapes (rectangles, circles, etc.), arbitrary paths, and

text. These objects can be given a wide variety of attributes such as color, gradient or pat-

terned fills, alpha blending, and markers. Objects can be transformed, cloned, and grouped.

Hyperlinks can be added for use in web browsers. The Inkscape program aims to be fully XML,

SVG, and CSS compliant.

Inkscape is available prepackaged for the Windows, Macintosh, and Linux operating systems.

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The program and its source code are freely available. They can be obtained from the Inkscape

website [http://www.inkscape.org/].

Inkscape is undergoing very rapid development with new features being added and compliance

to the SVG standard being constantly improved.

3.2.2 Inkscape Window

Start by opening Inkscape.This window contains several major areas, many containing clickable

icons or pull-down menus. The following figure shows this window and labels key parts.

The Command Bar, Snap Bar, Tool Controls, and Tool Box are detachable by dragging on the

handles (highlighted in blue) at the far left or top. They can be returned to their normal place

by dragging them back. New in v0.48: Some of the bars change position depending on which

option is selected at the bottom of the View menu. When Default is selected, the Command

Bar is on the top while the Snap Bar is on the right. When Custom is selected, the Command

Bar and the Snap Bar are both on the top. When Wide is selected, the Command Bar and

the Snap Bar are both on the right. By default, Default is used if you are not using a “Wide

Screen” display while Wide is used if you are. A width to height aspect ratio of greater than

1.65 is defined to be wide. These bars, as well as the Palette and Status Bar, can be hidden

using the View Show/Hide submenu.

As Inkscape has grown more complex, the area required to include icons and entry boxes for all

the various items has also grown leading to problems when Inkscape is used on small screens.

The Command Bar, Snap Bar, Tool Controls, and Tool Box have variable widths or heights.

If there are too many items to be shown in the width (height) of the Inkscape window, a small

down arrow will appear on the right side or bottom of the bars. Clicking on this arrow will

open a drop-down menu with access to the missing items.

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Figure 3.1: Inkscape Window

3.2.3 Inkscape Program

Inkscape has its roots in the program Gill (GNOME Illustrator application) created by Raph

Levian [http:// www.levien.com/] of Ghostscript fame. This project was expanded on by the

Sodipodi [http://sourceforge.net/projects/ sodipodi] program. A different set of goals led to

the split-off of the current Inkscape development effort.

The goal of the writers of Inkscape is to produce a program that can take full advantage of the

SVG standard. This is not a small task. A link to the road map for future development can

be found on the Inkscape website [http:// www.inkscape.org/].

Instructions on installing Inkscape can be found on the Inkscape website. Full functionality

of Inkscape requires additional helper programs to be installed, especially for importing and

exporting files in different graphic formats.

In this project the use of inkscape is to convert any image(formats) into graphics

code usually known as GCODE. .GCODE formats are generated by integrating

inkscape with necessary extension files.

3.2.4 Generating gcode files using inkscape

1. Download and install Inkscape 0.48.5 version.

2. Install an Add-on that enables the export images to gcode files.

3. Open the Inkscape, go to File menu and click ”Document Properties”.

4. Change the custom size.

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5. Now close this window.

6. Open the required image.

7. Re-size the image to fit our printing area.

8. Click Path from menu and ”Trace Bitmap”.Make required changes.

9. Click ok and close the window.

10. Now, move the gray scale image, and delete the color one behind it. Move the grey image

to the correct place again and click from Path menu ”Object to path”.

11. Final, go to file menu, click save as and select .gcode. Click ok on next window.

GCode Tools: Gcodetools is an open source Inkscape extension, to export gcode for use

with a CNC machine, written in the Python programming language. Inkscape extensions work

in the standard Unix IO model, taking SVG on standard input, and output transformed SVG on

standard output. The Gcodetools extension generates G-Code from the SVG input and writes

it to a file as a side effect of the SVG transformation. This python extension can be easily

downloaded as a .ZIP file from https://github.com/martymcguire/inkscape-unicorn

3.3 CAMotics

CAMotics is an Open-Source software which simulates 3-axis CNC milling or engraving. It is

a fast, flexible and user friendly simulation software for the DIY and Open-Source community.

CAMotics works on Linux, OS-X and Windows.

Being able to simulate is a critical part of creating CNC tool paths. Programming a CNC

with out a simulator is cutting without measuring; it’s both dangerous and expensive. With

CAMotics we can preview the results of your cutting operation before you fire up your machine.

This will save the time and money and open up a world of creative possibilities by allowing us

to rapidly visualize and improve upon designs without wasting material or breaking tools.

At home manufacturing is one of the next big technology revolut There have been major

advances in desktop 3D printing (e.g. Maker Bot) yet uptake of desktop CNCs has lagged

despite the availability of cheap CNC machines. One of the major reasons for this is a lack of

Open-Source simulation and CAM (3D model to tool path conversion) software. CAM and NC

machine simulation present some very difficult, yet not insurmountable, programming chal-

lenges. Whereas, 3D printing simulation and tool path generation are much easier.

CAMotics aims to be a useful CNC simulation platform for the DIY and Open-Source com-

munity. CAMotics should serve the highly technical user but remain simple and user friendly

enough to support less techie types as well.

22

Features

• Fast 3-axis cut-workpiece simulation with 3D visualization.

• Simulates cylindrical, conical, ballnose, spheroid and snubnose tool shapes.

• Tool path 3D visualization.

• Multi-threaded rendering can take advantage of multi-processor CPUs.

• GCode parsing, simulation, verification and annotation.

• Supports LinuxCNC (AKA EMC2) O-codes.

• Export cut workpiece to STL file.

• Tool table editing.

• Add height probing to 2D GCode files. Very useful for circuit board cutting and metal

engraving.

• 2D GCode path optimization.

• Operates in Windows and Linux.

• Released under the GPL v2+ license.

Limitations

• Simulates only snapshots of the cutting process.

• No 5-axis simulation.

• No Lathe simulation.

• No CAM facilities yet, e.g. 3D model to tool path conversion.

• No CNC machine control, not a replacement for LinuxCNC or MACH3.

• Does not yet detect over/under cutting, collisions with the tool shaft or fixtures or rapid

moves in the material.

• Not all of the LinuxCNC G-Code language is implemented, yet.

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3.4 Arduino IDE

The Arduino project provides the Arduino integrated development environment (IDE), which

is a cross-platform application written in the programming language Java. It originated from

the IDE for the languages Processing and Wiring. It is designed to introduce programming to

artists and other newcomers unfamiliar with software development. It includes a code editor

with features such as syntax highlighting, brace matching, and automatic indentation, and

provides simple one-click mechanism to compile and load programs to an Arduino board. A

program written with the IDE for Arduino is called a ”sketch”.

The Arduino IDE supports the languages C and C++ using special rules to organize code. The

Arduino IDE supplies a software library called Wiring from the Wiring project, which provides

many common input and output procedures. A typical Arduino C/C++ sketch consist of two

functions that are compiled and linked with a program stub main() into an executable cyclic

executive program:[.2cm]

• setup(): a function that runs once at the start of a program and that can initialize

settings.

• loop(): a function called repeatedly until the board powers off.

After compiling and linking with the GNU toolchain, also included with the IDE distribution,

the Arduino IDE employs the program avrdude to convert the executable code into a text

file in hexadecimal coding that is loaded into the Arduino board by a loader program in the

board’s firmware.

3.5 Processing 3.0.2

Processing is a simple programming environment that was created to make it easier to develop

visually oriented applications with an emphasis on animation and providing users with instant

feedback through interaction. The developers wanted a means to “sketch” ideas in code. As

its capabilities have expanded over the past decade, Processing has come to be used for more

advanced production-level work in addition to its sketching role. Originally built as a domain-

specific extension to Java targeted towards artists and designers, Processing has evolved into a

full-blown design and prototyping tool used for large-scale installation work, motion graphics,

and complex data visualization.

Processing is based on Java, but because program elements in Processing are fairly simple,

you can learn to use it even if you don’t know any Java. If you’re familiar with Java,

it’s best to forget that Processing has anything to do with Java for a while, until you get

the hang of how the API works. The latest version of Processing can be downloaded at

http://processing.org/download.

24

An important goal for the project was to make this type of programming accessible to a wider

audience. For this reason, Processing is free to download, free to use, and open source. But

projects developed using the Processing environment and core libraries can be used for any

purpose. This model is identical to GCC, the GNU Compiler Collection. GCC and its as-

sociated libraries (e.g. libc) are open source under the GNU Public License (GPL), which

stipulates that changes to the code must be made available. However, programs created with

GCC (examples too numerous to mention) are not themselves required to be open source.

Processing consists of:

• The Processing Development Environment (PDE). This is the software that runs when

you double-click the Processing icon. The PDE is an Integrated Development Envi-

ronment (IDE) with a minimalist set of features designed as a simple introduction to

programming or for testing one-off ideas.

• A collection of functions (also referred to as commands or methods) that make up the

“core” programming interface, or API, as well as several libraries that support more ad-

vanced features such as sending data over a network, reading live images from a webcam,

and saving complex imagery in PDF format.

• A language syntax, identical to Java but with a few modifications.

• An active online community, based at http://processing.org.

3.5.1 Sketching with Processing

A Processing program is called a sketch. The idea is to make Java-style programming feel

more like scripting, and adopt the process of scripting to quickly write code. Sketches are

stored in the sketchbook, a folder that’s used as the default location for saving all of your

projects. Sketches that are stored in the sketchbook can be accessed from File Sketchbook.

Alternatively, File Open... can be used to open a sketch from elsewhere on the system.

Advanced programmers need not use the PDE, and may instead choose to use its libraries with

the Java environment of choice. However, for a beginner, it’s recommended to use the PDE to

gain familiarity with the way things are done. While Processing is based on Java, it was never

meant to be a Java IDE with training wheels. The conceptual model (how programs work,

how interfaces are built, and how files are handled) is somewhat different from Java.

25

Figure 3.2: Processing Window

3.6 Conclusion

In this chapter a brief introduction about the type of software used,theoretical and some prac-

tical idea about Inkscape, CAMotics, Arduino IDE and Processing are discussed.

26

Chapter 4

Hardware

4.1 Introduction

In this hardware system consists of a metallic frame, on which is mounted three axis of motion

in a standard Cartesian coordinate system. X and Y axis is driven by a stepper motor driven

by a adafruit L293D motor driver circuit. Z axis is driven by a servo motor.

The different included parts in the project are:

• Arduino UNO.

• ADAFRUIT:MOtor Driver Shield L293D.

• Stepper Motors.

• Servo Motor.

4.2 Arduino UNO

The Uno is a microcontroller board based on the ATmega328P. It has 14 digital input/output

pins (of which 6 can be used as PWM outputs), 6 analog inputs, a 16 MHz quartz crystal,

a USB connection, a power jack, an ICSP header and a reset button. It contains everything

needed to support the microcontroller; simply connect it to a computer with a USB cable or

power it with a AC-to-DC adapter or battery to get started..Anyone can tinker with the UNO

without worrying too much about doing something wrong, worst case scenario you can replace

the chip for a few dollars and start over again. ”Uno” means one in Italian and was chosen to

mark the release of Arduino Software (IDE) 1.0. The Uno board and version 1.0 of Arduino

Software (IDE) were the reference versions of Arduino, now evolved to newer releases. The Uno

board is the first in a series of USB Arduino boards, and the reference model for the Arduino

27

platform; for an extensive list of current, past or outdated boards see the Arduino index of

boards.

The board features an Atmel ATmega328 microcontroller operating at 5 V with 2Kb of RAM,

32 Kb of flash memory for storing programs and 1 Kb of EEPROM for storing parameters.

The clock speed is 16 MHz, which translates to about executing about 300,000 lines of C source

code per second. The board has 14 digital I/O pins and 6 analog input pins. There is a USB

connector for talking to the host computer and a DC power jack for connecting an external

6-20 V power source, for example a 9 V battery, when running a program while not connected

to the host computer. Headers are provided for interfacing to the I/O pins using 22 g solid

wire or header connectors.

Overview of the Board

Figure 4.1: Arduino UNO

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4.3 Adafruit L293D Motor Shield

Arduino-compatible boards use printed circuit expansion boards called shields, which plug into

the normally supplied Arduino pin headers. Shields can provide motor controls, Global Posi-

tioning System (GPS), Ethernet, liquid crystal display (LCD), or breadboarding (prototyping).

• 2 connections for 5V servos connected to the Arduino’s high-resolution dedicated timer.

• Up to 4 bi-directional DC motors with individual 8-bit speed selection.

• Up to 2 stepper motors (unipolar or bipolar) with single coil, double coil, interleaved or

micro-stepping.

• 4 H-Bridges: L293D chipset provides 0.6A per bridge (1.2A peak) with thermal shutdown

protection, 4.5V to 25V.

• Pull down resistors keep motors disabled during power-up.

• Big terminal block connectors to easily hook up wires (10-22AWG) and power Arduino

reset button brought up top.

• 2-pin terminal block to connect external power, for seperate logic/motor supplies.

• Tested compatible with Mega, Diecimila, Duemilanove.

Before using the Motor shield, we must install the AFMotorArduinolibrary−thiswillinstructtheArduinohowtotalktotheAdafruitMotorshield, anditisn′toptional.

First, grab the library from github (http://adafru.it/aOA).

Uncompress the ZIP file onto your desktop.

Rename the uncompressed folder AFMotor.

Check that inside AFMotor is AFMotor.cpp and AFMotor.h files. If not, check the steps above.

Place the AFMotor folder into the arduinosketchfolder/libraries folder. For Windows, this will

probably be something like MY Documents/Arduino/libraries for Mac it will be something like

Documents/arduino/libraries. If this is the first time you are installing a library, you’ll need

to create the libraries folder. Make sure to call it libraries exactly, no caps, no other name.

Check that inside the libraries folder there is the AFMotor folder, and inside AFMotor Is

AFMotor.cpp AFMotor.h and some other files.

Quit and restart the IDE. You should now have a submenu called File-Examples-AFMotor-

MotorParty.

29

Figure 4.2: Adafruit L293D Motor Shield

4.4 Servo Motor

A servo motor is an electrical device which can push or rotate an object with great precision.

To rotate and object at some specific angles or distance, servo motor is used. It is just made up

of simple motor which run through servo mechanism. If motor is used is DC powered then it is

called DC servo motor, and if it is AC powered motor then it is called AC servo motor. We can

get a very high torque servo motor in a small and light weight packages. Doe to these features

they are being used in many applications like toy car, RC helicopters and planes, Robotics,

CNC Machine etc. The position of a servo motor is decided by electrical pulse and its circuitry

is placed beside the motor.

4.4.1 Working principle of Servo Motors.

A servo consists of a Motor (DC or AC), a potentiometer, gear assembly and a controlling

circuit. First of all we use gear assembly to reduce RPM and to increase torque of motor. Say

at initial position of servo motor shaft, the position of the potentiometer knob is such that there

is no electrical signal generated at the output port of the potentiometer. Now an electrical

signal is given to another input terminal of the error detector amplifier. Now difference between

these two signals, one comes from potentiometer and another comes from other source, will be

processed in feedback mechanism and output will be provided in term of error signal. This error

signal acts as the input for motor and motor starts rotating. Now motor shaft is connected

with potentiometer and as motor rotates so the potentiometer and it will generate a signal.

So as the potentiometer’s angular position changes, its output feedback signal changes. After

sometime the position of potentiometer reaches at a position that the output of potentiometer

30

Figure 4.3: Servo Motor

is same as external signal provided. At this condition, there will be no output signal from the

amplifier to the motor input as there is no difference between external applied signal and the

signal generated at potentiometer, and in this situation motor stops rotating.

4.4.2 Controlling Servo Motor

Servo motor is controlled by PWM (Pulse with Modulation) which is provided by the control

wires. There is a minimum pulse, a maximum pulse and a repetition rate. Servo motor can

turn 90 degree from either direction form its neutral position. The servo motor expects to see

a pulse every 20 milliseconds (ms) and the length of the pulse will determine how far the motor

turns. For example, a 1.5ms pulse will make the motor turn to the 90 position, such as if pulse

is shorter than 1.5ms shaft moves to 0 and if it is longer than 1.5ms than it will turn the servo

to 180.

Servo motor works on PWM (Pulse width modulation) principle, means its angle of rotation is

controlled by the duration of applied pulse to its Control PIN. Basically servo motor is made

up of DC motor which is controlled by a variable resistor (potentiometer) and some gears. High

speed force of DC motor is converted into torque by Gears. We know that WORK= FORCE X

DISTANCE, in DC motor Force is less and distance (speed) is high and in Servo, force is High

and distance is less. Potentiometer is connected to the output shaft of the Servo, to calculate

the angle and stop the DC motor on required angle. Servo motor can be rotated from 0 to

180 degree, but it can go up to 210 degree, depending on the manufacturing. This degree of

rotation can be controlled by applying the Electrical Pulse of proper width, to its Control pin.

31

Servo checks the pulse in every 20 milliseconds. Pulse of 1 ms (1 millisecond) width can rotate

servo to 0 degree, 1.5ms can rotate to 90 degree (neutral position) and 2 ms pulse can rotate

it to 180 degree.

Figure 4.4: Controlling of Servo Motor (PWM)

4.5 Stepper Motor

A stepper motor is a type of DC motor which has a full rotation divided in an equal number

of steps. It is a type of actuator highly compatible with numerical control means, as it is

essentially an electromechanical converter of digital impulses into proportional movement of its

shaft, providing precise speed, position and direction control in an open-loop fashion, without

requiring encoders, end-of-line switches or other types of sensors as conventional electric motors

require. he steps of a stepper motor represent discrete angular movements, that take place in

a successive fashion and are equal in displacement, when functioning correctly the number of

steps performed must be equal to the control impulses applied to the phases of the motor. The

final position of the rotor is given by the total angular displacement resulting from the number of

steps performed. This position is kept until a new impulse, or sequence of impulses, is applied.

32

These properties make the stepper motor an excellent execution element of open-loop control

systems. A stepper motor does not lose steps, i.e. no slippage occurs, it remains synchronous

to control impulses even from standstill or when braked, thanks to this characteristic a stepper

motor can be started, stopped or reversed in a sudden fashion without losing steps throughout

its operation.

Figure 4.5: Stepper Motor

4.6 Conclusion

In this chapter all the details about the hardwares used such as Arduino UNO board,Adafruit

L293D Motor Shield,Stepper Motors and Servo Motors are discussed.

33

Chapter 5

Industrial Design

5.1 Introduction

The complete mechanical system was designed in the metallic CD drive cover.

The designs in the project are :

• X-Y Direction.

• Pen setup.

• Stand holding the Whole.

• Final Setup

Y-axis: basic axis carries X-axis move from front to back.

X-axis: carries Z-axis move from left to right.

Z-axis: carries pen part move up and down.

5.2 X-Y Direction

In computing, an optical disc drive (ODD) is a disk drive that uses laser light or electromagnetic

waves within or near the visible light spectrum as part of the process of reading or writing data

to or from optical discs. Some drives can only read from certain discs, but recent drives can

both read and record, also called burners or writers. Compact discs, DVDs, and Blu-ray discs

are common types of optical media which can be read and recorded by such drives. Optical disc

drives that are no longer in production include CD-ROM drive, CD writer drive, and combo

(CD-RW/DVD-ROM) drive. As of 2015, DVD writer drive is the most common for desktop

PCs and laptops. There are also the DVD-ROM drive, BD-ROM drive, Blu-ray Disc combo

(BD-ROM/DVDRW/CD-RW) drive, and Blu-ray Disc writer drive.

The stepper motor setup of CD drives are used in X-Y direction co-ordinate axis.

34

Figure 5.1: Lens Frame in CD Drive (Containing Stepper Motor)

5.3 Stand holding the whole

The stand holding all the parts are made by the outer metallic cover of the cd drive. Two

covers are welded together perpendicularly for holding the x and y axis.

Figure 5.2: CD Drive Cover

5.4 Pen Setup (Z-axis)

For pen setup (z axis) high-density fiberboard (HDF) is used. It is a type of fiberboard, which

is an petroleum by product. It is of light weight.Servomotor is adjusted inside the HDF to get

the up and movement required to plot the object.

5.5 Final Setup

All the sections are integrated together to get a good output.

35

Figure 5.3: Pensetup

Figure 5.4: View 1 Figure 5.5: View 2

5.6 Conclusion

In this chapter the design setup used in this project is discussed to give an idea on the me-

chanical section.

36

Chapter 6

Overall View and Setup of the Project

6.1 Introduction

The following steps shows the building stages of a low cost mini cnc plotter. For X and Y axis,

the stepper motors from CD drive is used. Servo motor is used for z axis.Inkscape,Processing

and Arduino IDE gives the command from the computer as gcode to the arduino board to get

the plotted output

Main Block Diagram

Figure 6.1: Main Block Diagram

37

6.2 Steps Involved in the Project

Step 1-Industrial Design

1. First step to start building this cnc machine is to disassemble two dvd/cd drives and take

off them the stepper motors. Use the screwdriver to open them and take off them the

rails.

2. The outer metallic cover of cd drive is welded perpendicularly to make the stand holding

the x and y axis.

3. Attach the cd drive stepper motor setup as x and y axis. And make sure that the Y axis

is straight to CNC base and the X axis vertically to it.

4. Z axis (pen setup) is attached to the x axis. The pen setup is made up of HDF, the servo

motor is attached to it and the pen is setup inside the fiber using screw and spring.

5. A metallic base is attached to the Y axis for using as paper base. Then a paper is put

above it with the help some magnets.The printing area is 4x4cm.

Step 2-Arduino and Stepper Motor Setup

1. The adafruit L293D motor driver sheild compactible with the Arduino board is mounted

on it.

2. The Arduino is connected the computer port.

3. Check the stepper motors and the servo motor.

4. The stepper motors and the servo motor are connected to the motor shield.

5. The external power is connected. (Trainer Kit 12v,3A)

Step 3-Burning of Program and Gcode take in

1. The mini cnc plotting sketch is burned to the Arduino microprocessor (ATmega 328) by

using Arduino IDE.

2. Gcode is made by Inkscape program.

3. Then use the gctrl.pde processing program. This program sends ’gcode’ images to the cnc

plotter.

4. Plotting of the image is done.

38

6.3 Result

Integrating the software along with the hardware and mechanical systems makes up an effective

2D plotter.

Figure 6.2: Plotted Output Image

6.4 Conclusion

In this chapter the steps involved in setting-up the plotter and final result are discussed.

39

Chapter 7

Applications

The main applications of CNC machines comes in industrial field.Some of them are discussed

below:

• Metal Removal Applications – CNC machines are extensively used in industries where

metal removal is required. The machines remove excess metal from raw materials to create

complex parts. A good example of this would be the automotive industries where gears,

shafts and other complex parts are carved from the raw material. CNC machines are also

used in the manufacturing industries for producing rectangular, square, rounded and even

threaded jobs. All processes, such as milling, grinding, turning, boring, reaming, etc, can

be controlled and carried out by these CNC machines using specific machine tools for each

task.

• Metal Fabrication Industry – Many industries require thin plates for different pur-

poses. These industries use CNC machines for a number of machining operations such

as plasma or flame cutting, laser cutting, shearing, forming and welding to create these

plates. CNC plasma or laser cutters are used for shaping metal, while CNC turret presses

are used for operations like punching holes. Other operations like bending metal plates

can also be carried out with very high precision using CNC press brakes.

• Electrical Discharge Machining Applications – Electrical Discharge Machines, or

EDMs as they are also known, remove metal from the raw material by producing sparks

that burn away the excess metal. EDM machining through CNC automation is carried

out in two different ways; first through Wire EDM and second through Vertical EDM.

CNC automated Wire EDM is used to punch and then die combinations for creating die

sets used in the fabrication industry. CNC automated Vertical EDM requires an electrode

in the same size and shape as the cavity that needs to be carved out.

40

Chapter 8

Conclusion and Future Aspects

In modern CNC systems, end-to-end component design is highly automated using computer-

aided design (CAD) and computer-aided manufacturing (CAM) programs. The programs

produce a computer file that is interpreted to extract the commands needed to operate a

particular machine by use of a post processor, and then loaded into the CNCmachines for

production. Since any particular component might require the use of a number of different

tools – drills, saws, etc., modern machines often combine multiple tools into a single ”cell”.

In other installations, a number of different machines are used with an external controller and

human or robotic operators that move the component from machine to machine. In either

case, the series of steps needed to produce any part is highly automated and produces a part

that closely matches the original CAD design.

PCB Mill (Future)

A PCB Mill is a device that etches out a pattern on a copper clad board such that it makes a

Printed Circuit Board (PCB). PCBs are used everywhere in the field of electrical engineering

to connect electrical components to one another. Typically, after a board is designed, the

layout files are sent to a manufacturer who then makes the board and ships it back to the

customer. When prototyping, the delay and setup costs associated with sending a layout to a

manufacturer can often mean days of down time. While this may not seem costly at first, it can

prove to be a significant nuisance since most boards contain a wiring bug that was overlooked

or misunderstood and must then be remade.

41

Bibliography

1. Venkatram Ramachandran, Evaluation of Performance Criteria of CNC

Machine Tool Drive System, IEEE Transactions on Industrial Electron-

ics, Vol. 45, No. 3, June 1998, pp. 462-468.

2. Jae Wook Jeon and Young Youl Ha, A Generalized Approach for the

Acceleration and Deceleration of Industrial Robots and CNC Machine

Tools, IEEE Transactions on Industrial Electronics, Vol. 47, No. 1,

February 2000, pp. 133-139.

3. Allen G. Morinec, Power Quality Considerations for CNC Machines:

Grounding, IEEE Transactions on Industrial Electronics, Vol. 38, No. 1,

January/February 2002, pp. 3-11.

4. Dr M Shivakumar, Stafford Michahail, Ankitha Tantry H, Bhawana C K,

Kavana H and Kavya V Rao, Robotic 2D Plotter, International Journal

of Engineering and Innovative Technology (IJEIT), Volume 3, Issue 10,

April 2014, pp.300-303.

5. Venkata Krishna Pabolu et al., Design and Implementation of a Three

Dimensional CNC Machine (IJCSE) International Journal on Computer

Science and Engineering Vol. 02, No. 08, 2010, pp. 2567-2570.

6. Mrs. R. Dayana, Gunaseelan P, Microcontroller Based X-Y Plotter, In-

ternational Journal of Advanced Research in Electrical, Electronics and

Instrumentation Engineering, Vol. 3, Special Issue 3, April 2014.

7. Ahn Luong, Willis Lutz, Jared Springle, Ashton Snelgrove, Computer

numerical control 3 axis plotter, University of Utah, Computer Engi-

neering.

8. Hassam Salamah, Ja’far Yasin, PCB CNC Machine, An-Najah national

University, Computer Engineering.

9. W Durfee, Arduino Microcontroller Guide, University of Minnesota.

10. Steve Krar, Arthur Gill, Computer Numerical Control Programming

Basics.

11. Instuctables.com

12. Wikipedia.com

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[12pt,a4paper]report [top=0.80in, bottom=0.80in, left=0.8in,right=0.80in]geometry [utf8]inputenc

graphicx ragged2e

43

Appendices

44

.1 Programs

Program in Arduino UNO Board

#include <Servo.h>

#include <AFMotor.h>

#define LINE_BUFFER_LENGTH 512

// Servo position for Up and Down

const int penZUp = 130;

const int penZDown = 87;

// Servo on PWM pin 6

const int penServoPin = 9;

// Should be right for DVD steppers

const int stepsPerRevolution = 20;

// create servo object to control a servo

Servo penServo;

// Initialize steppers for X- and Y-axis using this Arduino pins for the L293D H-bridge

AF_Stepper myStepperY(stepsPerRevolution,1);

AF_Stepper myStepperX(stepsPerRevolution,2);

/* Structures, global variables */

struct point {

float x;

float y;

float z;

};

// Current position of plothead

struct point actuatorPos;

// Drawing settings, should be OK

float StepInc = 1;

int StepDelay = 0;

int LineDelay =40;

int penDelay = 150;

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// Motor steps to go 1 millimeter.

// Use test sketch to go 100 steps. Measure the length of line.

// Calculate steps per mm. Enter here.

float StepsPerMillimeterX = 100.0;

float StepsPerMillimeterY = 100.0;

// Drawing robot limits, in mm

// OK to start with. Could go up to 50 mm if calibrated well.

float Xmin = 0;

float Xmax = 40;

float Ymin = 0;

float Ymax = 40;

float Zmin = 0;

float Zmax = 1;

float Xpos = Xmin;

float Ypos = Ymin;

float Zpos = Zmax;

void setup() {

// Setup

Serial.begin( 9600 );

penServo.attach(penServoPin);

penServo.write(penZUp);

delay(200);

// Decrease if necessary

myStepperX.setSpeed(600);

myStepperY.setSpeed(600);

// Notifications!!!

Serial.println("Mini CNC Plotter alive and kicking!");

Serial.print("X range is from ");

Serial.print(Xmin);

Serial.print(" to ");

Serial.print(Xmax);

Serial.println(" mm.");

Serial.print("Y range is from ");

Serial.print(Ymin);

Serial.print(" to ");

46

Serial.print(Ymax);

Serial.println(" mm.");

}

/**********************

* void loop() - Main loop

***********************/

void loop()

{

delay(200);

char line[ LINE_BUFFER_LENGTH ];

char c;

int lineIndex;

bool lineIsComment, lineSemiColon;

lineIndex = 0;

lineSemiColon = false;

lineIsComment = false;

while (1) {

// Serial reception - Mostly from Grbl, added semicolon support

while ( Serial.available()>0 ) {

c = Serial.read();

if (( c == ’\n’) || (c == ’\r’) ) { // End of line reached

if ( lineIndex > 0 ) { // Line is complete. Then execute!

line[ lineIndex ] = ’\0’; // Terminate string

if (verbose) {

Serial.print( "Received : ");

Serial.println( line );

}

processIncomingLine( line, lineIndex );

lineIndex = 0;

}

else {

// Empty or comment line. Skip block.

}

lineIsComment = false;

lineSemiColon = false;

Serial.println("ok");

}

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else {

if ( (lineIsComment) || (lineSemiColon) ) { // Throw away all comment characters

if ( c == ’)’ ) lineIsComment = false; // End of comment. Resume line.

}

else {

if ( c <= ’ ’ ) { // Throw away whitepace and control characters

}

else if ( c == ’/’ ) { // Block delete not supported. Ignore character.

}

else if ( c == ’(’ ) { // Enable comments flag and ignore all characters

lineIsComment = true;

}

else if ( c == ’;’ ) {

lineSemiColon = true;

}

else if ( lineIndex >= LINE_BUFFER_LENGTH-1 ) {

Serial.println( "ERROR - lineBuffer overflow" );

lineIsComment = false;

lineSemiColon = false;

}

else if ( c >= ’a’ && c <= ’z’ ) { // Upcase lowercase

line[ lineIndex++ ] = c-’a’+’A’;

}

else {

line[ lineIndex++ ] = c;

}

}

}

}

}

}

void processIncomingLine( char* line, int charNB ) {

int currentIndex = 0;

char buffer[ 64 ]; // Hope that 64 is enough for 1 parameter

struct point newPos;

newPos.x = 0.0;

newPos.y = 0.0;

while( currentIndex < charNB ) {

48

switch ( line[ currentIndex++ ] ) { // Select command, if any

case ’U’:

penUp();

break;

case ’D’:

penDown();

break;

case ’G’:

buffer[0] = line[ currentIndex++ ]; // /!\ Dirty - Only works with 2 digit commands

// buffer[1] = line[ currentIndex++ ];

// buffer[2] = ’\0’;

buffer[1] = ’\0’;

switch ( atoi( buffer ) ){// Select G command

case 0: // G00 & G01 - Movement or fast movement. Same here

case 1:

// /!\ Dirty - Suppose that X is before Y

char* indexX = strchr( line+currentIndex, ’X’ );

char* indexY = strchr( line+currentIndex, ’Y’ );

if ( indexY <= 0 ) {

newPos.x = atof( indexX + 1);

newPos.y = actuatorPos.y;

}

else if ( indexX <= 0 ) {

newPos.y = atof( indexY + 1);

newPos.x = actuatorPos.x;

}

else {

newPos.y = atof( indexY + 1);

indexY = ’\0’;

newPos.x = atof( indexX + 1);

}

drawLine(newPos.x, newPos.y );

// Serial.println("ok");

actuatorPos.x = newPos.x;

actuatorPos.y = newPos.y;

break;

}

break;

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case ’M’:

buffer[0] = line[ currentIndex++ ];// /!\ Dirty - Only works with 3 digit commands

buffer[1] = line[ currentIndex++ ];

buffer[2] = line[ currentIndex++ ];

buffer[3] = ’\0’;

switch ( atoi( buffer ) ){

case 300:

{

char* indexS = strchr( line+currentIndex, ’S’ );

float Spos = atof( indexS + 1);

// Serial.println("ok");

if (Spos == 30) {

penDown();

}

if (Spos == 50) {

penUp();

}

break;

}

case 114: // M114 - Repport position

Serial.print( "Absolute position : X = " );

Serial.print( actuatorPos.x );

Serial.print( " - Y = " );

Serial.println( actuatorPos.y );

break;

default:

Serial.print( "Command not recognized : M");

Serial.println( buffer );

}

}

}

}

/*********************************

* Draw a line from (x0;y0) to (x1;y1).

* int (x1;y1) : Starting coordinates

* int (x2;y2) : Ending coordinates

**********************************/

void drawLine(float x1, float y1) {

50

if (verbose)

{

Serial.print("fx1, fy1: ");

Serial.print(x1);

Serial.print(",");

Serial.print(y1);

Serial.println("");

}

// Bring instructions within limits

if (x1 >= Xmax) {

x1 = Xmax;

}

if (x1 <= Xmin) {

x1 = Xmin;

}

if (y1 >= Ymax) {

y1 = Ymax;

}

if (y1 <= Ymin) {

y1 = Ymin;

}

if (verbose)

{

Serial.print("Xpos, Ypos: ");

Serial.print(Xpos);

Serial.print(",");

Serial.print(Ypos);

Serial.println("");

}

if (verbose)

{

Serial.print("x1, y1: ");

Serial.print(x1);

Serial.print(",");

Serial.print(y1);

Serial.println("");

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}

// Convert coordinates to steps

x1 = (int)(x1*StepsPerMillimeterX);

y1 = (int)(y1*StepsPerMillimeterY);

float x0 = Xpos;

float y0 = Ypos;

// Let’s find out the change for the coordinates

long dx = abs(x1-x0);

long dy = abs(y1-y0);

int sx = x0<x1 ? StepInc : -StepInc;

int sy = y0<y1 ? StepInc : -StepInc;

long i;

long over = 0;

if (dx > dy) {

for (i=0; i<dx; ++i) {

myStepperX.onestep(sx,MICROSTEP);

over+=dy;

if (over>=dx) {

over-=dx;

myStepperY.onestep(sy,MICROSTEP);

}

delay(StepDelay);

}

}

else {

for (i=0; i<dy; ++i) {

myStepperY.onestep(sy,MICROSTEP);

over+=dx;

if (over>=dy) {

over-=dy;

myStepperX.onestep(sx,MICROSTEP);

}

delay(StepDelay);

}

}

if (verbose)

{

Serial.print("dx, dy:");

52

Serial.print(dx);

Serial.print(",");

Serial.print(dy);

Serial.println("");

}

if (verbose)

{

Serial.print("Going to (");

Serial.print(x0);

Serial.print(",");

Serial.print(y0);

Serial.println(")");

}

// Delay before any next lines are submitted

delay(LineDelay);

// Update the positions

Xpos = x1;

Ypos = y1;

}

// Raises pen

void penUp() {

penServo.write(penZUp);

delay(penDelay);

Zpos=Zmax;

digitalWrite(15, LOW);

digitalWrite(16, HIGH);

if (verbose) {

Serial.println("Pen up!");

}

}

// Lowers pen

void penDown() {

penServo.write(penZDown);

delay(penDelay);

Zpos=Zmin;

53

digitalWrite(15, HIGH);

digitalWrite(16, LOW);

if (verbose) {

Serial.println("Pen down.");

}

}

*//Program used in Processing for loading Gcode//*

import java.awt.event.KeyEvent;

import javax.swing.JOptionPane;

import processing.serial.*;

Serial port = null;

// select and modify the appropriate line for your operating system

// leave as null to use interactive port (press ’p’ in the program)

String portname = null;

//String portname = Serial.list()[0]; // Mac OS X

//String portname = "/dev/ttyUSB0"; // Linux

//String portname = "COM6"; // Windows

boolean streaming = false;

float speed = 0.001;

String[] gcode;

int i = 0;

void openSerialPort()

{

if (portname == null) return;

if (port != null) port.stop();

port = new Serial(this, portname, 9600);

port.bufferUntil(’\n’);

}

void selectSerialPort()

{

54

String result = (String) JOptionPane.showInputDialog(this,

"Select the serial port that corresponds to your Arduino board.",

"Select serial port",

JOptionPane.PLAIN_MESSAGE,

null,

Serial.list(),

0);

if (result != null) {

portname = result;

openSerialPort();

}

}

void setup()

{

size(500, 250);

openSerialPort();

}

void draw()

{

background(0);

fill(255);

int y = 24, dy = 12;

text("INSTRUCTIONS", 12, y); y += dy;

text("p: select serial port", 12, y); y += dy;

text("1: set speed to 0.001 inches (1 mil) per jog", 12, y); y += dy;

text("2: set speed to 0.010 inches (10 mil) per jog", 12, y); y += dy;

text("3: set speed to 0.100 inches (100 mil) per jog", 12, y); y += dy;

text("arrow keys: jog in x-y plane", 12, y); y += dy;

text("page up & page down: jog in z axis", 12, y); y += dy;

text("$: display grbl settings", 12, y); y+= dy;

text("h: go home", 12, y); y += dy;

text("0: zero machine (set home to the current location)", 12, y); y += dy;

text("g: stream a g-code file", 12, y); y += dy;

text("x: stop streaming g-code (this is NOT immediate)", 12, y); y += dy;

y = height - dy;

text("current jog speed: " + speed + " inches per step", 12, y); y -= dy;

55

text("current serial port: " + portname, 12, y); y -= dy;

}

void keyPressed()

{

if (key == ’1’) speed = 0.001;

if (key == ’2’) speed = 0.01;

if (key == ’3’) speed = 0.1;

if (!streaming) {

if (keyCode == LEFT) port.write("G91\nG20\nG00 X-" + speed + " Y0.000 Z0.000\n");

if (keyCode == RIGHT) port.write("G91\nG20\nG00 X" + speed + " Y0.000 Z0.000\n");

if (keyCode == UP) port.write("G91\nG20\nG00 X0.000 Y" + speed + " Z0.000\n");

if (keyCode == DOWN) port.write("G91\nG20\nG00 X0.000 Y-" + speed + " Z0.000\n");

if (keyCode == KeyEvent.VK_PAGE_UP) port.write("G91\nG20\nG00 X0.000 Y0.000 Z" + speed + "\n");

if (keyCode == KeyEvent.VK_PAGE_DOWN) port.write("G91\nG20\nG00 X0.000 Y0.000 Z-" + speed + "\n");

if (key == ’h’) port.write("G90\nG20\nG00 X0.000 Y0.000 Z0.000\n");

if (key == ’v’) port.write("$0=75\n$1=74\n$2=75\n");

//if (key == ’v’) port.write("$0=100\n$1=74\n$2=75\n");

if (key == ’s’) port.write("$3=10\n");

if (key == ’e’) port.write("$16=1\n");

if (key == ’d’) port.write("$16=0\n");

if (key == ’0’) openSerialPort();

if (key == ’p’) selectSerialPort();

if (key == ’$’) port.write("$$\n");

}

if (!streaming && key == ’g’) {

gcode = null; i = 0;

File file = null;

println("Loading file...");

selectInput("Select a file to process:", "fileSelected", file);

}

if (key == ’x’) streaming = false;

}

void fileSelected(File selection) {

if (selection == null) {

56

println("Window was closed or the user hit cancel.");

} else {

println("User selected " + selection.getAbsolutePath());

gcode = loadStrings(selection.getAbsolutePath());

if (gcode == null) return;

streaming = true;

stream();

}

}

void stream()

{

if (!streaming) return;

while (true) {

if (i == gcode.length) {

streaming = false;

return;

}

if (gcode[i].trim().length() == 0) i++;

else break;

}

println(gcode[i]);

port.write(gcode[i] + ’\n’);

i++;

}

void serialEvent(Serial p)

{

String s = p.readStringUntil(’\n’);

println(s.trim());

if (s.trim().startsWith("ok")) stream();

if (s.trim().startsWith("error")) stream(); // XXX: really?

}

57

.2 Arduino UNO Board

.3 L293D Specifications (Motor Driver IC)

The Device is a monolithic integrated high voltage, high current four channel driver designed to

accept standard DTL or TTL logic levels and drive inductive loads (such as relays solenoides,

DC and stepping motors) and switching power transistors. To simplify use as two bridges each

pair of channels is equipped with an enable input. A separate supply input is provided for

the logic, allowing operation at a lower voltage and internal clamp diodes are included. This

device is suitable for use in switching applications at frequencies up to 5 kHz. The L293D is

assembled in a 16 lead plastic packaage which has 4 center pins connected together and used

for heatsinking The L293DD is assembled in a 20 lead surface mount which has 8 center pins

58

connected together and used for heatsinking.

Figure .31: Pin Out

Figure .32: Maximum Ratings

59

Figure .33: Electrical Ratings

60