NOTE: The instructable is still under construction. I wanted to publish it now though so people could see what the Eggbot can do and in case anyone wants to use any of my designs for their own Easter Eggs. I'll finish it up soon.
A couple of weeks ago I got an Egg-bot. My kids and I have loved it, so I thought I'd share some example of what it can do, a few designs we've come up with and some general tips.
If you're not familiar with an Egg-bot, it's essentially a little CNC lathe. You put somewhat spherical objects two plungers that are controlled by a stepper. There's also a pen arm that is controlled by a stepper that moves side to side. Between the two steppers (and a servo to lift and lower the pin) the Egg-bot is able to take instructions from a computer and use them to draw on an egg. The de-facto platform for creating drawings and plotting them on eggs is Inkscape (and open source Illustrator-like program).
I've found it surprisingly easy to use and a ton of fun.
Step 1: Quickstart
1. Connect your Egg-bot to power and to your computer via USB
2. Put an egg (or whatever you're going to draw on in the Egg-bot).
3. Open your drawing in Inkscape (I'd start with something from the EB_Example_Set )
4. Open the Egg-bot control in Inkscape (Extensions -> Eggbot -> Eggbot Control)
5. Lift the Pen arm - in the Egg-bt control click the Setup tab, make sure "Toggle pen up/down" is selected and click apply, wait for motors to move, then click apply again (the first apply will set the pen at the "down" position, the second apply will move it up).
6. Put a pen in then pen arm. Then pen should over the center of the egg. It should be somewhere between 1/8" and 1/16" over the egg.
7. Move the pen arm from side to side to make sure it's not touching the egg when the pen arm is up. If it is touching you can adjust the "Pen up position" in the Setup tab of the Eggbot control. After you change the number click apply once, wait until the pen lowers, then click apply again. Now verify it's still not touching when you move the pen arm from side to side.
8. Move the pen far the the right, in the Setup tab of the Eggbot control click apply to drop the pen. Make sure the pen is touching the egg. If it's not you may need to push the pen lower in the arm, lower the arm using the screw, or adjust the "pen down position" in the dialog. Manually lift up the pen and move the pen arm over to the left and make sure it's also touches the egg there.
9. In the setup tab click apply to raise the pen arm. Now center the pen arm on the egg.
10. Click on the Plot tab in the Eggbot control and click apply, the eggbot will start drawing.