Mini CNC 2D-Plotter aus ausgedientem DVD-Laufwerk mit L293D Motor Shield

Komponenten und Zubehör

Arduino UNO	×	1
L293D Motor Shield	×	1
Tower Pro Servo Motor 9g	×	1
Ausgedientes DVD-Laufwerk	×	1
Jumper Kabel (generic)	×	1

Apps und Online-Dienste

• Arduino IDE
• Processing IDE
• Inkscape

Projektbeschreibung

Zwei ausgediente DVD-Laufwerke wie im Bild angeordnet

1. Arduino IDE herunterladen
2. Processing IDE herunterladen
3. Arduino IDE öffnen und Code von hier laden
4. Processing IDE öffnen und Code von hier laden

Ausgedientes DVD-Laufwerk öffnen, internen Schlitten (mit Schrittmotor-Mechanik) entnehmen. Dieser dient als X- und Y-Achse. Bilder beachten für Montage. Loch in leeres DVD-Gehäuse bohren, X- und Y-Achse mit Schrauben/Muttern am jeweiligen Gehäuse befestigen.

Beide Achsen senkrecht zueinander ausrichten.

G-Code

Für G-Code-Dateien, die mit diesem CNC-Plotter kompatibel sind, wird Inkscape benötigt.

Inkscape: Professionelle Vektorgrafik-Software (Windows, Mac, Linux). Nutzung durch Designer & Hobbyisten für Illustrationen, Icons, Logos, Diagramme, Karten, Webgrafiken. Nutzt W3C-Standard SVG als natives Format, frei & Open Source. Download: inkscape.org.

Wichtig: Version 0.48.5 herunterladen! Add-on für G-Code-Export installieren: hier mit Installationshinweisen.

Video-Tutorial auf YouTube ansehen: G-Code-Datei erstellen.

• gctrl-Datei in Processing IDE laden, Play-Button klicken.
• 'p' drücken → Kommunikationsport wählen
• Optional: Jog-Speed mit '1', '2', '3' setzen
• 'g' drücken → G-Code-Datei laden
• Enter drücken → Plotter startet

Plotter ist bereit. Fertige G-Code-Beispiele:

• Hisoka.gcode
• papay.gcode
• spong1.gcode

Danke für Ihre Aufmerksamkeit! Vollständige Anleitung hier.

Video zur Live-Demo:

Code

• Arduino CNC Code
• Processing Code

Arduino CNC Code Arduino

#include <Servo.h>
#include <AFMotor.h>

#define LINE_BUFFER_LENGTH 512
char STEP = MICROSTEP;

// Servo Positionen für Stift hoch/runter
const int penZUp = 95;
const int penZDown = 83;

// Servo an PWM Pin 10
const int penServoPin = 10;

// Für DVD-Schrittmotoren passend, aber nicht kritisch
const int stepsPerRevolution = 48;

Servo penServo;

// Stepper für X- und Y-Achse über L293D H-Brücke
AF_Stepper myStepperY(stepsPerRevolution, 1);
AF_Stepper myStepperX(stepsPerRevolution, 2);

struct point { float x; float y; float z; };
struct point actuatorPos;

float StepInc = 1;
int StepDelay = 0;
int LineDelay = 0;
int penDelay = 50;

float StepsPerMillimeterX = 100.0;
float StepsPerMillimeterY = 100.0;

float Xmin = 0, Xmax = 40;
float Ymin = 0, Ymax = 40;
float Zmin = 0, Zmax = 1;
float Xpos = Xmin, Ypos = Ymin, Zpos = Zmax;

boolean verbose = false;

void setup() {
  Serial.begin(9600);
  penServo.attach(penServoPin);
  penServo.write(penZUp);
  delay(100);
  myStepperX.setSpeed(600);
  myStepperY.setSpeed(600);
  
  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 "); Serial.print(Ymax); Serial.println(" mm.");
}

void loop() {
  delay(100);
  char line[LINE_BUFFER_LENGTH];
  char c;
  int lineIndex = 0;
  bool lineIsComment = false, lineSemiColon = false;

  while (1) {
    while (Serial.available() > 0) {
      c = Serial.read();
      if (c == '\n' || c == '\r') {
        if (lineIndex > 0) {
          line[lineIndex] = '\0';
          if (verbose) { Serial.print("Received: "); Serial.println(line); }
          processIncomingLine(line, lineIndex);
          lineIndex = 0;
        } else {
          // Leere/Comment-Zeile überspringen
        }
        lineIsComment = false; lineSemiColon = false;
        Serial.println("ok");
      } else {
        if (lineIsComment || lineSemiColon) {
          if (c == ')') lineIsComment = false;
        } else {
          if (c <= ' ') { /* Whitespace ignorieren */ }
          else if (c == '/') { /* Block delete nicht unterstützt */ }
          else if (c == '(') { 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') {
            line[lineIndex++] = c - 'a' + 'A'; // Uppercase
          } else {
            line[lineIndex++] = c;
          }
        }
      }
    }
  }
}

void processIncomingLine(char* line, int charNB) {
  int currentIndex = 0;
  char buffer[64];
  struct point newPos = {0, 0, 0};

  while (currentIndex < charNB) {
    switch (line[currentIndex++]) {
      case 'U': penUp(); break;
      case 'D': penDown(); break;
      case 'G':
        buffer[0] = line[currentIndex++];
        buffer[1] = '\0';
        switch (atoi(buffer)) {
          case 0: // G00
          case 1: // G01
            // X vor Y angenommen
            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);
            actuatorPos.x = newPos.x;
            actuatorPos.y = newPos.y;
            break;
        }
        break;
      case 'M':
        buffer[0] = line[currentIndex++];
        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);
            if (Spos == 30) penDown();
            if (Spos == 50) penUp();
            break;
          }
          case 114: // M114 Position melden
            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);
        }
        break;
    }
  }
}

void drawLine(float x1, float y1) {
  if (verbose) { Serial.print("fx1, fy1: "); Serial.print(x1); Serial.print(","); Serial.print(y1); Serial.println(); }
  
  // Begrenzung
  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(); }

  // Koordinaten in Steps
  x1 = (int)(x1 * StepsPerMillimeterX);
  y1 = (int)(y1 * StepsPerMillimeterY);
  float x0 = Xpos, y0 = Ypos;

  long dx = abs(x1 - x0);
  long dy = abs(y1 - y0);
  int sx = (x0 < x1) ? StepInc : -StepInc;
  int sy = (y0 < y1) ? StepInc : -StepInc;
  long i, over = 0;

  if (dx > dy) {
    for (i = 0; i < dx; ++i) {
      myStepperX.onestep(sx, STEP);
      over += dy;
      if (over >= dx) { over -= dx; myStepperY.onestep(sy, STEP); }
      delay(StepDelay);
    }
  } else {
    for (i = 0; i < dy; ++i) {
      myStepperY.onestep(sy, STEP);
      over += dx;
      if (over >= dy) { over -= dy; myStepperX.onestep(sx, STEP); }
      delay(StepDelay);
    }
  }

  if (verbose) { Serial.print("dx, dy: "); 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(LineDelay);
  Xpos = x1; Ypos = y1;
}

void penUp() {
  penServo.write(penZUp);
  delay(penDelay);
  Zpos = Zmax;
  digitalWrite(15, LOW); digitalWrite(16, HIGH);
  if (verbose) Serial.println("Pen up!");
}

void penDown() {
  penServo.write(penZDown);
  delay(penDelay);
  Zpos = Zmin;
  digitalWrite(15, HIGH); digitalWrite(16, LOW);
  if (verbose) Serial.println("Pen down.");
}

Processing Code Java

import java.awt.event.KeyEvent;
import javax.swing.JOptionPane;
import processing.serial.*;

Serial port = null;
String portname = null; // null = interaktiv ('p' im Programm)
// 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() {
  String result = (String) JOptionPane.showInputDialog(frame,
    "Select the serial port that corresponds to your Arduino board.",
    "Select serial port", JOptionPane.QUESTION_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 current location)", 12, y); y += dy;
  text("g: stream a g-code file", 12, y); y += dy;
  text("x: stop streaming g-code (NOT immediate)", 12, y); y += dy;
  y = height - dy;
  text("current jog speed: " + speed + " inches per step", 12, y); y -= dy;
  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 == '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) { println("Window closed or cancelled."); }
  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?
}

Schaltpläne

Alle Komponenten wie in Abbildung verbinden: