Making your first plot

Introduction

So now you have your EggBot assembled and connected, and you've installed Inkscape and the EggBot extension (and any necessary USB drivers). How do you successfully draw on your first egg using the EggBot?

Using the Inkscape EggBot Control Extension

The Inkscape EggBot Control Extension is the tool that you will use to help you test and align the EggBot, as well as transfer your drawings to an egg. First you'll need to start Inkscape. Once Inkscape is running, you'll have an Extensions menu, and on that menu will be a menu item labeled Eggbot ...; selecting that menu item will open the Eggbot dialog.

The Eggbot dialog has several tabs, as follows:

• Plot -- This tab is used to transfer (plot) a drawing from Inkscape to the egg.
• Setup -- Use this tab to set the pen's up and down positions.
• Timing -- This tab will allow you to tweak some of the timing values for EggBot actions.
• Options -- This tab will allow you to configure some of the EggBot's behavior.
• Manual -- This tab will allow you to control the EggBot itself (turning motors, lifting/dropping the pen, etc.)
• Resume -- This tab describes how to pause a plot, and how to resume plotting.
• Layers -- This tab will give you control over which drawing layers to plot (for multi-color drawings).
• `*` -- This tab will display information about the Eggbot extension and the EggBot itself.

Prepare your EggBot for drawing on eggs

Your first instinct will be to put a pen in the pen arm, put an egg in the egg cups, and start drawing. This is an excellent way to frustrate yourself and ruin an egg. Instead, you want to be able to place an egg in the egg cups such that the egg is evenly aligned, and the pen arm will have firm contact with the egg as it rotates.

To do that, follow these steps:

1. Set the motors. From the Setup tab, select Raise pen, turn off motors, then click Apply. This will unlock the motors, leaving them free to rotate, with the pen arm in the right position to put a pen over the egg.
2. Set the pen arm arc depth. The pen motor mounts with screws through slots, so that the depth of its drawing arc can be changed. On the inside of the chassis sidewall, there's a gauge and some simple illustrations indicating rough positions for the motor. A chicken egg will typically use the center position; a round glass bulb (such as a lightbulb or decorative ball) will use the top position; a duck or goose egg may need the bottom position. Gently loosen the screws, slide the motor to the correct height, and then gently tighten the screws.
3. Place a pen in the pen arm. Uncapped, point down, (of course) so you can judge how it will align with the egg. Tighten the thumbscrew to fix the pen position. Rotate the pen arm until it is vertical.
4. Align the headstock. The headstock (containing the egg motor) is connected to each of the sidewalls with 3 screws. Gently loosen the screws on each side until the headstock barely slides. You'll want to slide the headstock until the equator of an egg placed against the headstock (south pole towards the headstock) is directly beneath the pen arm. Once you like the position of the headstock, set the egg aside and tighten the headstock screws on each sidewall, taking care to ensure that headstock meets each sidewall at the same place on the gauges.
5. Align the tailstock. The tailstock (containing the spring-loaded plunger) is connected to the sidewalls with screws, just like the headstock. Gently loosen the screws on each side until the tailstock barely slides. With an egg placed against the headstock egg cup, set the egg's north pole in the plunger egg cup, and then slide the tail stock until the plunger O-ring (between the two sides of the tailstock) is roughly in the middle. Once you like the position of the tailstock, set the egg aside and tighten the tailstock screws on each sidewall, taking care to ensure that tailstock meets each sidewall at the same place on the gauges.
6. Calibrate the pen up/pen down positions. Need to add info here
7. Set the pen arm height. Place an egg between the egg cups, and a pen in the pen arm such that the pen is a few millimeters above the surface of the egg. You may need to raise or lower the pen arm, by loosening the thumbscrew that holds the proximal pen arm to the pen arm backer. Tighten the screw when the pen is just above the egg surface. Swivel the pen arm over the egg to check clearance.

Mount An Egg in the EggBot

1. Remove pen (if any) from the pen arm.
2. Start with a clean, dry, room-temperature, raw egg.
   • Dry, so your marker will adhere.
   • Room-temperature, so that your egg will stay dry.
   • Raw, so that you can empty it out afterwards, in the event that you get a good one. (Yes, you could hard-boil your eggs, but then you'll have to break them to get the centers out. Or you could empty them first, but that's an awful lot of effort if an egg doesn't turn out right.)
   • Clean, so that ink flow is not affected by grease on the surface. You may even want to use rubber gloves for handling your eggs to keep greasy finger prints off (especially important if using technical pens with very fine nibs.)
3. Push back the plunger and roughly center the end of the egg on the headstock. Gently return the plunger to the other end of the egg. Spin the egg to see if it is centered, and adjust position as necessary.

Drawing on your Egg

1. From the Manual tab, select Enable Motors, then click Apply. Then select Raise Pen then click Apply.
2. Put a pen in the pen arm.
3. Begin with vector art in inkscape.
4. From the Plot tab, press apply, and the EggBot should print the entire drawing.

For multiple color printing, keep different color information in separate layers of your Inkscape document named with an initial number. (e.g. 1-red, 2-black). Use the Layers tab to plot layer by layer, changing the pen between layer plots.