The Ostrich Egg-Bot kit is a special version of The Original Egg-Bot kit with an extra-large chassis that fits larger objects, up to 6.25" in diameter.
Both models-- the original and this extra large one --are open-source art robots capable of drawing on the surfaces of spherical or egg-shaped objects. They are descendents of the very first Eggbot, designed by Bruce Shapiro, dating back to 1990.
An Eggbot is super adjustable, and is designed to draw on all kinds of things that are normally "impossible" to print on. Not just eggs but pool balls, light bulbs, mini pumpkins, and even things like wine glasses. In the photos, you can see just a few of the things that you can make with an Ostrich Eggbot: Incredible decorated glass balls, christmas ornaments, emu eggs, and even chicken eggs.
The Ostrich Eggbot chassis is CNC-cut at the Evil Mad Scientist shop in California, out of hardwood plywood, with laser engraved calibration and assembly marks. The pen and egg motors are high-torque precision stepping motors, and the pen lift mechanism is a quiet and reliable servo motor. Brass thumbscrews are provided as standard hardware.
The kit is easy to assemble in a couple of hours, and only requires a couple of basic tools like miniature Phillips-head and flathead screwdrivers. You'll also need a recent-vintage computer with an available USB port (Mac, Windows or Linux), plus internet access to download assembly instructions and necessary software.
No soldering or programming are required.
Basic operation is much like that of a printer driver: you import or make a drawing in Inkscape, and use the extensions to plot your drawing onto whatever object you've mounted in the Eggbot. It's all handled through an easy to use graphical user interface, and works cleanly on Mac, Windows and Linux.
The standard pen holder included with the EggBot kit is designed to fit various art pens including Sharpie Ultra Fine Point pens. However, it can actually fit almost any pen (or pencil, or crayon, or just about anything else) of similar size.
If you have additional questions about Eggbot kits, you may want to look at the Eggbot FAQ.
Ostrich Eggbot documentation is hosted at the Evil Mad Science Wiki, and you may also be interested to see the documentation there for the (standard size) Original Egg-Bot Kit.