I have a unifence as well- which is they type of fence. The locking mechanism is a bit fussy until you get used to it. To engage it with the t-slot on the front of the rail you have to turn the handle about 15* counter-clockwise, slip the locking cam into the t-slot on the rail, then turn the handle back to top dead center for it to be attached to the rail. Then you push the handle down to lock it. It's going to sound REALLY confusing unless you're looking at the saw. When you get to the saw- turn the fence upside down and look at the locking cam on the inside of the slot where it attaches to the rail, and you'll see what I"m talking about. If it slides freely along the rail- don't bother with what I just said, don't rotate the handle, just leave it there and move the handle up and down to lock and unlock it.

On this fence you can take of the guide and have it in the position it's in now, and a "low" position. There are two lines in the little clear window with a drawing of the fence in either position. I think the "high" position reads at the left, but I don't quite remember. Just match up the cross section of the guide with the position your guide is in and you'll be fine. The scale on my saw is extremely accurate, but if it's not your saw, you can't assume it will be accurate. Set it to your measurement, and make a little test cut. Just enough so that the blade cuts through the top of the piece of wood, then use your tape measure to see if its the correct width.

Beyond using this specific fence, find some articles and/or videos on line and brush up on safe use of a table saw. They can be pretty dangerous.

m