fully printable optical potentiometer/encoder

Have you ever needed to add a rotational sensor to a robot? They are really expensive and so I tried to make a fully printable optical potentiometer.

Take a look at my Blog to get more informations
http://coolrobotprojects.blogspot.co.at/

The open-Frameworks-Code that generates the Gradient/Encoder-pattern:
https://github.com/thunderbug1/encoder_pattern_generat

The generation of the non radial pattern works but the radial ones don´t.

The thing that´s still missing is a little paper ring with a gradient on it and which is glued to the rotor.

MK1: (First version)

for the photoelectric fork sensor I use this: http://www.pollin.de/shop/downloads/D120592D.PDF

MK2: (Actual early preview)

Sensor: http://www.pollin.de/shop/downloads/D120525D.PDF (Version A)