Hi, I am trying to attach this belt to this metal rod. I was wondering how I could go about doing so. We have access to a mill, nice drill, band saw etc… and I was thinking of milling a hole into the gear, but was not sure how big the gear would need to be. Anyways sorry if this is not enough information, any help is appreciated.
Also, for some reason the picture is upside down.
http://www.chiefdelphi.com/forums/attachment.php?attachmentid=11778&stc=1&d=1328579897
You’ll need sort of gear to attach to the rod. You should have some gears that came in the kit of parts that fit the belt. You’ll need to drill the hole in the gear and then build a “key” (small piece of metal that slides into a groove in the gear and the rod). The key keeps the gear from slipping on the rod.
Let me know if that helps.
FWIW, your terminology is a bit off. 
There are a number of ways to secure a pulley to the shaft (provided you want a live axle). You can go with the way smclean suggested, broaching a keyway into the shaft and then using a key to hold it in place. Alternatively, you could file flats onto the shaft and use set screws to hold it in place (most pulleys come with set screws).
Adding to slijjin’s comment, you may also want to make sure that the pulleys that you use have a flange on them so that the belt doesn’t fly off. Also you could make a set of lexan washer instead of pulleys with flanges. As for as attaching the pulleys, boring out a hole with a lathe (if available, if not a mill will work just fine.) and broaching the key slot.
P.S. McMaster sells rods with key slots already in them.
So I’m assuming that is a 1/2" inch steel rod? The belts that came in KOP I believe are 5mm pitch HTD from Gates, so you can order Sprockets/belts from here: http://www.sdp-si.com/eStore/CoverPg/Drive_Components.htm
Be sure to try to get the ones with a flange as bhumudar mentioned, so the belt stays on better. Keyway broaches for the sprocket you can get from McMaster, and you could either get a key cutter, or just use the right sized endmill to make a slot in the shaft.
Speaking from experience, if those belts are going to have significant load on them, I would avoid relying on merely a set screw. You could try milling a flat onto your shaft, but the set screw will probably slip without it.
