Centering saw blade

I am not familiar with the model so I don't know how the top comes off but usually they aren't held down by much.

Usually it only needs the plastic or aluminium insert to be removed to access the riving knife or to remove the blade.

A maladjusted riving knife is a common cause of a "catching" blade.

It is worth considering, when such saws arrive they usually need calibrating, which often means semi-dismantling the saw and rebuilding it with a higher degree of precision than the factory can muster - using a large trusted set square, an accurate blade height gauge, etc.
It is also worth considering many modern table saws also have an electric brake that is supposed to stop the blade in a couple of seconds when the power is switched off.

It usually gets mounted to the riving knife that sticks up behind the blade.

I assume you are talking about the riving knife behind the blade.
when you take the hole cover off the saw table, you'll see a lever down on the side of the riving knife that can be either straight up or you can pivot it down toward the blade. When its up, its for through cuts, the riving knife sticks up higher than the blade. <b>When you turn the lever down toward the blade, the riving knife drops down a bit so you can make kerfs that don't go all the way through the wood.</b>
When you take the blade out, you can also take the riving knife out if you are going to put a dado cutter in, but <b>don't remove the riving knife</b> otherwise.

Wood has all kinds of internal stresses that are relieved when you cut the wood. Often the slot the blade cuts results in the two sides of the wood curving together and pinching the blade. This if very dangerous because the back of the blade can get pinched and through your wood at you faster than a major league pitcher can throw a fast ball. I still have a bruise on my chest from this happening to me before thanksgiving. Good thing it was the whole end of a 2x4 and the wood didn't split into a sharp spear as the blade grabbed it. Don't take out the riving knife unless you are using a dado blade and then put it back in right afterwards.

If you don't have one, here's the manual for your saw:
http://tinyurl.com/npkv29o

Are you asking how to add one or what?

I'll suggest you look at the removable Excalibur Riving Knife from Merlin, which I've used(loved) or the Shark guard, which I haven't.

Glad you figured it out. The 4512 is a great saw. I hope you are enjoying making some dust!

ok thank you for reporting that your problem was solved.

I ran into that kind of problem with my Craftsman 10 table saw. I (an usual) over analyzed the problem and looked at moving the entire motor assembly from left to right slightly. In the end, I found that that the blade stablizer plates I used on the left and right of the blade, moved the blade that little bit needed to make the blade tips make contact. I removed the two stablizer plates, reinstalled the blade with the normal to flat washers and gave it a try. The blade now cleared the insert when pushed all the way to 45 degrees.

You might want to look to make sure there are no extra washers/spacers on the arbor that might move the blade slightly left or right from its normal position.

The blade and fence must be parallel to the miter slot. Splitter or riving knife needs to be parallel to the blade.

The saw has a bolt in the center of the blade. The saw blade will have to be held in place, (so it can't turn), while the bolt is being loosened. Pay attention to the rotation direction, as your replacement will need to rotate in the same direction. Once you have removed the bolt, there is a centering spacer that fits between the bolt and the blade, remove it paying attention to how it fits..you will need to put it on the new blade in the same manner. You can now remove your blade and replace. Good Luck. I hope this is very helpful!