Yes you need the resistor, if you dont then you will blow the LED as it is needed to limit the current to it. You dont have to be exact with that resistor so if you have any close you could use them.
Hood

ok found a suitable resistor.

so is it the blue wire that goes to the input on my break out board?

all help welcome

Yes the blue is the input to the BOB (Breakout Board seeing as I forgot to answer your previous question )

Hood

excellent thanks.

i got two sensors just incase so fingers crossed

sorry what are these? do i need them?

http://www.rapidonline.com/Electronic-Components/Transistor-output-optoswitch-29427

http://www.rapidonline.com/Electronic-Components/Transistor-Darlington-photo-interrupter-68054

more sensors, these are from Rapid.

oh right but i dont actually need them if i have the other sensors?

i didnt get round to wireing tonight as i made one of these from scratch again -




could i just confirm before i wire tomorrow

so i apply 5v to white wire of sensor
add resistor then 5v to red wire of sensor
connect green and black wires to 0v or gnd of 5v psu
connect blue wire to input/break out board?

Connect one end of resistor and white wire to 5v. Connect Red to other side of resistor. Connect green and black to 0v and Blue to an input.
Take the 5v and 0v from your breakout board if it has connections for them.
You may need to widen the slot, it looks narrow, I used to use 10mm wide slot on a 100mm disc and it worked great. Also remember to make sure the Index Debounce is set to 0  in General Config. Some people have needed a small amount of Index debounce when using different sensors but with the OPB optos I always had it at zero.
Hood

oh ok

i dont have 5v to take from BOB so im using a seperate one of these -

http://www.ebay.co.uk/itm/220986283308?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

slight over kill i know but its all ive got at the moment

my slot is 4mm wide, to narrow? my disk is just 70mm dia