HELP Lathe spindle indexing for speed and screwing

[keith wainwright]

Hello all I have hit the limit of my knowledge and its bl***y frustrating. I am trying to get the index function to work in mach 3 . The settings in mach are no problem (i think) as i can get the index to work in a simple way but i don't trust its accuracy. What i have done is wire a reed switch to a bob input and have a magnet pass it every rev and this works sort of . Problem is it vibrates and it may not be accurate enough to screw. it displays the revs ok and lets me calibrate the spindle ok but would rather use a disk and sensor set up. So bought on of these EE-SX672A Slot 5mm Photo Micro Sensor Switch ( don't know how to change font back) So it has 4 connections +, -, L, and out,. I have a12 volt 200 ma supply and the input on my bob reads 14 volts 8.8 ma . thats milliamp not mega amp . so please does any one know how to wire this and if so can you please tell me .I have got every thing to work properly even the tool changer but this has got me stumped thanks