CIRCUITS

The 3D printer has a small circuit tower composed of Siggorific Printed Circuit Boards. These were etched on the Modela onto copper blanks (see Parts List) via cad.py. Click the links to download the PNG files.

One of these is the board for the Power Supply:

Another of these boards is the H-Bridge for changing the polarization of the motor to get bi-directional control:

And the H-Bridge Control Center:

EXTRUDER

SOFTWARE

We wrote an application that translates our special file format and sends it to the 3D printer over a serial connection. The application is written in Python, with a user interface built with the Tkinter toolkit. The user interface allows the user to load, view, and send a file to the printer. It also allows the user to pause the print job so that pasta can be reloaded into the extruder during printing, or the position of the extruder can be adjusted manually. The program, seen below, is called fabaroni.py

The control program accepts files with a set of motor rotations. The file format is:

dx0, dy0, dz0;
dx1, dy1, dz1;
dx2, dy2, dz2;
...

Where dxn is the number of rotations applied to the motor controlling the x position of the extruder in the nth instruction, dyn is the number times to rotate the motor controller the y position of the extruder, etc.

fabaroni.py converts this file format into instructions that can be sent to the printer over serial. It splits each instruction into a set of packets that are sent to the motor controllers.

The packets sent for each instruction are formatted as follows:

The client also has some features for debugging: the buttons along the bottom can be used to move and control the printer manually.

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