In this lesson, we'll be filleting sharp corners. After completing this lesson, you'll be able to use Rule Fillet and use Fillet. Let's carry on with the file from our previous example. First, I want to rename "Sketch 3," and I'm going to call this "Frame Cutouts." The next thing that we want to do is go back in and round off these corners. So, we're going to use a feature from the modified drop-down called "Rule Fillet." We're going to "Input Features or Faces," and we're going to select the last extrude cut that we did to remove all that internal material. We're going to place a "Radius" of "two millimeters," and we're going to change the "Topology Option" to "All Fillets." Now, all fillets will be the internal edges, and you'll notice it gave us a warning. Now, the warning is actually in relation to this tight corner right here. This is something that we're going to have to go back and fix manually, but you can see that it added fillets on all of the other square corners. It took care of these edges, and it took care of these edges around here, but notice it didn't take care of any of the external edges. And the reason this is is because we're using a feature; we're only putting the feature that cut these originally. If we select the original extrude that we could also take care of these external ones, but we're going to come back and actually use a different radius value. All of the faces that produced problems, the ones that threw up the warning, are highlighted in blue. Now, some of these are fine, like the small holes in the slots, they don't need fillets obviously, but again, these areas we will have to address. So, we're going to go ahead and say "OK." We're going to hit "F" on the keyboard to manually create a fillet, and we're going to start to select these vertical edges around where our power distribution board and flight controller are going to mount. Now, one way that we could have approach this is by taking a different approach to the geometry itself, not leaving such a sharp corner there. I'm going to say "two millimeters." And notice that it's actually able to fillet that just fine. The reason it originally had some issues is because of the geometry. Again, it was causing issues there. And I might also want to change this and do a smaller fillet in that corner, like a one millimeter. We're going to go ahead and say "OK" with "one millimeter" there. Lastly, we want to go ahead and take care of these external edges, so we have ones on either side. Now, remember the end goal here is to do a water jet or a laser-cut type CNC tool path. So, there's no point in us trying to round off the upper or lower edges because that's not something that we can do with a water jet. These are only 2D cuts. So on these external edges, I'm going to use a radius value. It's quite a bit larger and just say "10 millimeters." We're going to say "OK", go back to a top view, and take a look at the chassis. Now, depending on the amount of mass that you're going to be carrying, depending on a few other factors, we might need to increase the strength here. But the entire goal is for us to learn how to create a parametric model, one that has features that can be controlled by parameters such as the original sketch, and then, we want to take that information, and we want to create a CNC program. So at this stage, just go ahead and save our file so that we can move onto the next step of creating a program.