I recently tried to use this: http://arduinoprojects101.com/arduino-rpm-counter-tachometer/ But it doesn't seem to be working. I used the Infrared Emitter and Detector from Radioshack: http://www.radioshack.com/product/index.jsp?productId=2049723 would that be an issue? Any suggestions?
The radioshack components are a normal IR led and a normal IR transistor. So that should work.
Are you sure everything is connected as in the picture ?
Are you sure its emitting light? You can test this easily with a camera.