The magnet needs to be glued to the Geneva disc in approximately the position shown. This is just INSIDE the raised plastic "cam" that operates the turntable, and level with its end. You will need to practice this first, because the magnet sticks very well to tweezers etc!

The sensor can be mounted conveniently underneath the turntable. To do so, turn the turntable upside down and mount the sensor in line with the bearing hole and 9mm out from the edge as shown. The sensor can be either way up and the orientation of the wires does not matter; it is the position of the body over the magnet that is important.

You can also print this template to get the necessary sensor position.