Searching for sensors

[Adam Y.]

Originally Posted by Andrew Schreiber

I should have been more clear, I dont like them for sensing position of a system that has slip. My issue with them was that our drive system had this knack for accelerating quickly and the wheels slipped occasionally. This meant that our robot thought it was further than it was.That being said, I would use these if I needed to know how fast a gear was spinning due to them being a no contact sensor. Mounting an encoder would mean that the encoder shaft would be spinning at High RPM which causes wear and the potential to have them wear out. In short, it depends on your use.

That isn't a problem with the sensor more than it is bad engineering to try and use the gear tooth sensor in that manner. If you want to reliably measure the distance between a goal and the robot you have to use a sensor like ultrasonic.
Also, you typically mount an encoder in a way to reduce the number of RPMs it rotates.