Circular 2D fillets

A fillet is a concave junction where two curves or surfaces meet. You can create 2D fillets to combine multiple curves with an arc between them. Sometimes it's easier to create two curves and fillet them together in order to create a corner than it is to draw out one curve with the corner in it. An example might be when you need to create a corner out of two perpendicular curves (Figure 7.54).

Figure 7.54. Use the 2D Fillet tool to add smooth corners to a set of curves.

To create a circular 2D fillet:

1.	Create two curves to fillet between (Figure 7.55). Figure 7.55. Two curves intersecting.
2.	Right-click the first curve, and select Curve Point from the marking menu.
3.	Click the first curve, and drag the point to where you want the fillet to arc (Figure 7.56). Figure 7.56. Click and drag a curve point into the place where you would like the arc to begin.
4.	Right-click the second curve, and select Curve Point from the marking menu.
5.	-click the second curve, and drag the point to where you want the fillet to arc (Figure 7.57). Figure 7.57. The two curve points determine the start and end points of the arc.
6.	Choose Edit Curves > Curve Fillet. An arc is created between the two curve points (Figure 7.58). Figure 7.58. An arc is created between the two curve points selected on each curve.

Keep Originals

Many of the curve and surface manipulation and rebuild commands have a Keep Originals option. When you rebuild a curve using a command such as Detach, the Keep Originals option lets you retain the original curve in addition to creating the new curve(s) as a result of the specific rebuild command.

Be aware that you may not notice that the original curve or surface is still present because the new curves or surfaces will sit directly on top of the original.