Each Etch-A-Frame behaves in much the same way as a standard Etch-A-Sketch, but with one important difference: Each frame has a connected and synchronized pair, providing a simple tool for remote collaborative drawing.
When an etching dial on a frame is rotated, the corresponding dial on the connected frame also rotates creating both an image and a sort of ghostly telepresence. Shaking a frame will erase the image in both frames of the connected pair.
Two servos will be connected to each of the dials which control both the input for etching and the telepresence output on the connected frame. The etching will achieved using traditional Etch-A-Sketch design with two orthogonal rails mounted on a pulley system which moves the etching stylus. An overview of the design can be seen here.
4 x Futaba Continuous Rotation Servo: $56
2 x Arduino Uno Boards: Provided by group
Steel Wire: Provided by group
Plug in outlet PCs to handle networking and USB connection: Provided by group
18" x 24" acrylic sheet for gears and supporting structure: $14
Wood (Mahogany?) for frame and dials: $40
My experience with mechanical design for the internal pulley system is limited. I need to investigate and prototype how this system could work reliably before attempting the final design. I am also looking into different methods for erasing the picture remotely - this could be difficult.
Week of 10/25: Prototype internal pulley system
Week of 11/01: Full CAD design
Week of 11/08: Laser cut supporting frame and internal gears and shopbot the wooden cover and dials
Week of 11/15: Internal circuitry wired up to servos
Week of 11/22: Hook servos up to mechanical pulley system
Week of 11/29: Network programming to connect frames
Week of 12/06: Testing and polish
12/13: Present the working frames
Parts listed above come to a total of $110.