We (3132) are using hall effect sensors with a buffering circuit this year. We developed them in the off-season for our 2012 shooter wheels.
We use Hall Effect sensors from RS (
http://australia.rs-online.com/web/p...-ics/7384743/).
We are mounting the board flat underneath our shooter wheel, and 'hanging' the magnets down off the wheel. The magnets are epoxied into a piece of aluminium hex stock that was turned to a taper and had a hole drilled in it for the magnet. A thread was then tapped into the other end of the piece, to mount it on the end of the bolt holding the wheel on.
When mounting them, make sure that the sensor itself can't move, so that it can't be sheared off by whatever it's measuring or drift away from the magnet.
I'm attaching a picture of the board, and a picture of our magnet mounts (before the pcb is attached), as well as the schematic for the buffering circuit. Let me know if you have any questions.