Pizza Plotter

Bringing personal fabrication to your kitchen: the pizza Plotter. During one of the last lectures I gave for Creative Technology about reprap‘s and personal fabrication one of the pizza hungry students (Symplexity) pointed out the necessary connection between pizza and production. Thus the idea for a Pizza Printer was born.

The previous posts on the Repstrap describe a 3D carthesian robot made from dot Matrix printer parts (using ONLY parts from three StarLC10 printers). Instead of the Z-axis the nozzle of a pressure plant mister was put on the head. The tank has been filled with tomato sauce. See the results on youtube below:

OK. admittedly, the accuracy needs some work. This has more to do with pressure / extrusion control than with the 2D robot. (which is basically an ordinary ottantotto controlled plotter now). The original StarLC10 power supply has been used, along with part of the casing. A standard RC servo has been added to the plant mister nozzle, allowing for on-off control for move- and draw commands. The ottantotto controls three stepper motors directly (using four wires per motor). The original stepper driver chips (STA401A) have been salvaged and re-used. For all the motors a single STA401 has been used. The control signals of both parallel motors have been bridged.

A drawing is made using a very simple processing sketch, based on the ‘file-save’ examples.

/**
* sketchtool, based on the 'filesave' example.
* move mouse. Every time you click, a datapoint will be saved
*/
int[] x = new int[0];
int[] y = new int[0];
void setup()
{
size(512, 512);
frameRate(30);
}
void draw()
{
background(204);
stroke(0);
noFill();
beginShape();
for (int i = 0; i < x.length; i++) { vertex(x[i], y[i]); } endShape(); // Show the next segment to be added if (x.length >= 1) {
stroke(255);
line(mouseX, mouseY, x[x.length-1], y[x.length-1]);
}
}
void mousePressed() { // Click to add a line segment
x = append(x, mouseX);
y = append(y, mouseY);
}
void keyPressed() { // Press a key to save the data
String[] lines = new String[x.length];
for (int i = 0; i < x.length; i++) { lines[i] = x[i]*4 + "t" + y[i]*4; } saveStrings("positions.txt", lines); exit(); // Stop the program }

Tomato Sauce and Pressure Vats are a match made in white-wall hell. At least until I fully understood the merits of hose-clamps. Luckily, if you are quick enough, the stains wash off well.

The printing program is equally simple (but will follow in a next post) The Ottantotto software has been made using winavr (since it involves timer interrupts, and I really love the AVRlib libraries from procryon)