• 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. driver board)
• 1 servo (mini 9g ~3$)
• a few M4 and M5 screws, washers and nuts
• a couple of screws to mount the pieces to the base plate
• 1 spring
• 1 rubberband
• "Oogoo" (silicon and corn starch) to the paddings
• baseplate in any scrap wood material (my was laminated)
• pencils
• (optional USB keyboard with stickers)
• style cheat sheet

##Challanges

• Backlash in the geared steppers was mitigated with software backlash compensation for the rotating axis and with a rubberband for the moving arm. [resolved]
• Finding the perfect tention so that the egg doesn't slip (making it moving less than expected 360 degrees) [still experimenting]

Firmware

https://github.com/ahd71/incedm