Interactive numerical controlled egg-decorating machine

- Inspired of the orignal egg-bot I designed a interactive variant for egg-decoration.
- Designed to be easily assembled and printed (no support required if oriented properly while printing)
- Controlled via serial interface (i use putty to connect, any terminal will do)
- Video: https://www.youtube.com/watch?v=KuiRFXf5oMg

##Modes of operation
- Direct control (move left/right, rotation forward/reverse) and pen up/down keys like an etch-and-sketch
- 360 degrees patterns via simple numerical commands. ("Pattern button" followed by one to three digits do select pattern, frequency and width)

##Pen mount (alternatives)
- Set-screw with captive nut
- Inserts tailored for the correct pen dimension (https://www.youtube.com/watch?v=yXb-T4F5XGk)

##Bill of material
- 3d printed parts (PLA)
- 1 arduino (or standalone atmega328p) with serial connection to host computer
- 2 driver boards (ULN2003 based)
- 2 stepper motors (28BYJ48 DC 5V) (~3$ each from China incl. d