3. 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 bthe 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,
meaningthat it can position that tool head at a precise point in or on the
material to create the cutor operation desired at that point.
4. By moving the head through multiple points, the cuttinghead can cut or sculpt
the design represented by a data stream of positioning points being sentby the
PC. By controlling a CNC machine through a PC it is possible for the user to
designa 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.
5. System Features
• Rapid speed positioning using G00
• Plot line using G01
• Plot Circles using G02,G03 clockwise or anti-clock wise.
• Manual Mode control the position of the Plotter using Keyboard
• Programming Mode write full program includes moving plotter, Arithmetic
operation and decisions instructions
6. 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.
7. Aim of thesis
Aim of the thesis is to set up a 2D Mini CNC Machine for the following
constraints:
• A general idea of CNC Models.
• Generating GCODE. Integrating the diffrent softwares along with the
hardware. setup.
9. Hadware
● 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.
10. 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.
12. 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.
13. Servo motor can turn 90 degree from either
direction form its neutral position.
14. 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.
15.
16. Software
Engineering as a discipline often requires more integration than large amounts of
original development. 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.
17. Components can be purchased, or may be freely available, as in the case of Open
Source software. 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.
L293D DC motor control
