Tamago

TAMAGO (Technology for Automated Milling of Avian Gestational Objects) is a CNC machine for eggshells. It has three degrees of freedom, one for the egg rotation and two for the end effector. The X and Z motion are coupled such that the tool follows the curvature of the shell.

The machine is designed as a kit. In the current version we use MDF for the construction material.

The machine is designed to fit eggs of hight from 5 to 10cm which includes hen, duck and goose eggs.

Design

Fabrication

Electronics and Software

To drive and control the three stepper motors, we use three low voltage stepper motor driver carriers from pololu linked to an arduino uno.

For the software part, the machine uses an arduino and processing based system.

To take into account the curvature of the shell, the Z and X axis are coupled to represent two degrees of freedom. The tool moves along the X+Z/2 or X-Z/2 axis and along the Z axis to descend on the shell.

Result

The egg is aligned on its rotation axis through two small rubber cups and is held in position by a string.

The tool (currently a pen) is placed on the toolholder in such a way that its weight maintains it in contact with the shell without exercing extra force on it.

There is no motion on the Y axis and the tool is always aligned vertically with the plane of symmetry of the egg.

Drawings examples