printable encoder for motors

hey I´m just looking for a cheap dc motor with an optical quadrature encoder but I´m wondering why all of these encoders are that expensive in relation to the actually relatively simple technology behind it(just leds and phototransistors for a simple one). So I thought that it would be great if we would have a simple printable encoder that fits or is sizable to fit most of the small dc motors. So what would be the simplest, cheapest and most versatile design for it, any ideas?

[www.thingiverse.com] could help.

yes I´ve already looked at that site and I thought about something like this
[www.thingiverse.com]
but more accurate, with an enclosure and with holes in the disk instead of revlective and none revlective stripes.

I ´ll make something like that when I have more time for it than now.

If you print it large with relatively large sections, a Laser printer might suffice. Just print it onto clear overhead projector film, make sure you get the stuff that works with a Laser printer. If you have a color Laser printer, you might find that some color other than black works well.

Or build a CNC rotary table and drill the holes. It'll be as accurate as the steps of the stepper motor.

Steve Greenfield AE7HD
OlyMEGA

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Steve Greenfield AE7HD
OlyMEGA
[www.olymega.org]

you could use an inexpensive resistive encoder. They're pretty darned precise and have long operational lives. I used them for feedback from an airbag capture system at NASA back in the 1990s. Basically like an end to end potentiometer without stops. Grey scale encoders aren't cheap because they're expensive to make.