/diy/ - Do It Yourself

>>1277703
>how do you get encoders from a closed-source printer system?

http://homofaciens.de/technics-base-circuits-transmissive-optical-sensors_en.htm#F4210

http://reprap.org/wiki/Optical_encoders_01

then

https://github.com/misan/dcservo

You need to tune the PID but it works.

Generally you can find ground by hooking it up to the printers circuit board and running a continuity test. The other side of the LED is then 5 volts and the remaining two wires are channel A and B.