# Tool directions – Lesson 10 – Alphacam Router Tutorial

Let’s prepare geometry for applying toolpats. Open the first part, p1-geometry-2d.

First, hide the Dimensions layer and the Construction layer.

Let’s turn on the visibility of the geometry direction arrows (Ctrl + G). In addition to the fact that one arrow means one geometry, it also indicates the direction and machining side. If the arrow is centered on the contour, it means that the tool will follow the contour with its center. So we get an undercut on the workpiece.

For circles with diameters 100, 17 and 15, the arrow should be inside the contour.

Because the outer contour and these circles will be milling, and when milling operations, the position and direction of the arrows determine the side on which the cutter will move and the direction in which it will move.

Holes 9 and 11 will be drilled. The position and direction of the arrows are irrelevant for drilling operations.

Ok, so to change the direction and direction of the arrows, from the Machine tab select the option Tool Directions. We have two sections here, Open Geometries and Closed Geometries. Open geometries are those whose beginning and end do not touch. So, for example, the line is open geometry.

In our drawing, all geometries are closed, so we will use the Closed geometries section.

We can specify the Direction and Side. We’ll start with the outer contour. Select CW as the Direction and select Outside as the Side.

Do not close this window and indicate the geometry of the outer contour. Ok, the arrow changed the direction and processing side.

Now we will go to the circles. Set CCW as Direction, and Inside as Side.

Do not close the window and indicate circles with diameters 100, 17 and 15.

Ok, the directions and side are already set, so we can close the window.