Quick tune up of the 3/8" chisel.

Since we need a 3/8" dado, we'll be using the formula with the 2 blades and 1 chipper.

Since this won't be a through cut, remove the riving knife and/or splitter. Sawstop only change your the brake to your dado brake.

3/8" width and 3/8" depth, this is easy! Check your depth using either a nifty gadget like this or any ruler/combination square.Turn the blade to make sure you didn't measure from what will be the absolute top of the cut.

Damn I need to clean my dado stack!

Use a ruler or square to set your distance from the fence, this will end up being the offset from the side of the piece to the inside edge of the dado. NOTE: If you're getting much closer than this, it's best to clamp a sacrificial piece of wood along your fence. Would suck to accidentally hit your fence with your blade.

I would normally use a piece of wood here, but since it was far enough from the blade I put a clamp directly on the fence that will act as a stop for the piece.

Let's get this party started!

Dado's create a bunch of dust

Dado is cut to the stop, and just needs some cleaning up to the far edge.

Use a sharp chisel or knife to sever the fibers. You don't have to go crazy beating on it, take your time and take several passes.

Use a small sharp chisel to pair away the waste to remove the ramp the dado stack left.

You get the point here. Take your time, don't try to remove all of it at once or you'll probably get tear out.

Check your depth often to try to not go too deep when you're pairing away the waste.

Use a sharp chisel or knife to sever the fibers. You don't have to go crazy beating on it, take your time and take several passes.

Optionally you can use a router plane to remove the waste and flatten the bottom.

Check your depth often to try to not go too deep when you're pairing away the waste.

Yay, we can stop pairing or planing.

Yay, grab a cold drink and celebrate your table saw stopped dado cut. Normally you would cut down the piece to final length and get rid of the end milling from the lumber yard, but since this was a piece with knots I'm going to end up tossing - I just left it there.