Reply to DJ Rasteri's homemade Scratch Controller

A homemade scratch controller.

Video:
http://www.youtube.com/watch?v=T2j5OoIu5kw
Home WIKI page:
http://www.midibox.org/dokuwiki/scratchcontroller
Pictures:
http://picasaweb.google.com/rasteri/Scratchtroller

The rotary controller is just a black& white pattern printed out onto a transparent acetate sheet and stuck to the rim of the scratch disk. This pattern is read by two infrared LED/Sensor pairs (positioned by hand and stuck down with Duct tape!) to generate the quadrature signal. The top of the scratch wheel is aluminium foil used as a capacitive touch sensor, and it's mounted on the spindle of an old floppy drive:

http://www.youtube.com/watch?v=bNtCZN97R3I

The single most expensive part was the optical crossfader. Great results!