CNC Machine 2D Plotter

CNC Machine 2D Plotter

Document content

o   Abstract

o   Introduction

o   History

o   System Features

o   System Architecture

o   Mechanical subsystem

o   Electronic subsystem

o   Software subsystem

o   Terminal App

o   Interpreter

o   Timer

o   Geometry Kernel

o   Motor Library

o   Testing and Deployment

 Abstract 

CNC Machine 2D Plotter (AVR C, C#): 

o   Aims to automate Plotter to produce images by moving a pen held by structure that can move the pen in two orthogonal directions the plotter can raise and lower the pen as required to create the desired image. 

o   This is done using Ardiuno, Stepper Motor and Geometric Algorithm such as bresenham's line drawing algorithm and midpoint circle drawing the system was tested and simulated under proteus

Introduction 

Computer numerical control (CNC) machines are automated milling machines that make industrial components without human assistance. This is possible because CNC machines are fed a series of instructions that are delivered to an internal computer controller. These instructions are in the form of codes that belong to the numerical control programming language.The code used to program CNC machines is generically called  G-code. However, G-code instructions are only part of the programming language. Specifically, G-codes give CNC machines the coordinates.


History 

The first commercial NC machines were built in the 1950's, and ran from punched tape.

CNC, and later CNC, allowed for tremendous increases in productivity for machine tools because the machines could be run automatically without requiring constant attention from their operator.

                   

The first commercial NC

www.cnccookbook.com

 System Features

•  Modes of control:

     -Calibration Mode (CL) Manual Mode controls the position of the plotter X,Y,Z

     -Load Mode (LD) Stores a program written with language similar to G-code and execute it using START instruction this mode has a restriction that the size of program must not exceed 20 instruction.

     -Execution Mode (EXE) communication protocol happened through serial UART. the micro-controller sends an acknowledge with the state of program and the ID of the next instruction should be executed and wait for the PC to send it. Using this mode allow us to write a program larger than 20 instructions as the whole program will be saved on the Computer memory

The following table describes the control commands with its specification

Command	Description
CL	Manual Mode using W,S,A,D,Q,Z buttons on the keyboard
LD	Load  Program on the micro-controller RAM
START	Execute the program stored on the RAM of micro-controller
EXE	Read G_Line from serial and executed  it immediately and   acknowledge the next instruction and state of  the program
RESET	Reset the machine to the initial X_co,Y_co_Z_co coordinates
SETBX	Set border of our board on  X-axis
SETBY	Set border of our board on Y-axis
SETBZ	Set border of our board on Z-axis

§ Language specification XG-code

Array of lines responsible for telling the machine what to do Arithmetic/decision/moving plotter instructions we don't implement the standard of G-code so we call it XG-code

Command	Description
G00	Rapid speed positioning X,Y,Z Vector.
G01	linear interpolation between 2 points Bresenham line drawing.
G02	Clockwise circle using Bresenham circle
G03	ANTI-Clockwise circle using Bresenham circle
ADD	ADD operand [2] and operand [3] then put result set on Operand [1].
MUL	MUL operand [2] and operand [3] then put result on Operand [1].
JEQ	Jump if flag is set.
JNE	Jump if flag is reset.
CMP	Compare operand [1] and operand [2] and set Equal flag.
EOP	End of program.

                                            

   

 CNC 2D Plotter DEMO