The actions you can specify for the tool to perform on a surface group are: Avoid, Machine, Gouge, and Fixture. The examples below show some scenarios where it can be useful to use the Avoid/Machine Surfaces when programming toolpaths.
In the example below, the flat toolpath is machining the floor and the wall in the outermost pass. While this may be desirable in certain scenarios, in this case you may want to avoid machining the floor and the wall at the same time to avoid excessive load on the tool. To avoid machining the wall, you can select the wall surface and set the action to Avoid.
Flat toolpath machining floor and wall
In the operation dialog, go to the Geometry tab.
In the Avoid/Machine Surfaces group, click to add a surface group. The Faces dialog opens.
With the Selection button active, select the wall surfaces on the model that you want to avoid.
Selecting wall surfaces to avoid
From the Action group of buttons, select Avoid.
Specify a Radial Clearance and an Axial Clearance.
Click OK.
After generating the toolpath, you can see that the flat toolpath now machines the floor but avoids the wall by the radial clearance value.
Tool avoids wall because of radial clearance
In the example below, a steep and shallow toolpath is machining a fillet using a machining boundary. As the machining boundary is a projection of the geometry in 2D, it may be better to use the Avoid/Machine Surfaces group to machine the fillet.
In the operation dialog, go to the Geometry tab.
In the Avoid/Machine Surfaces group, click to add a surface group. The Faces dialog opens.
With the Selection button active, select the fillet surfaces on the model that you want to machine.
Selecting fillet surface to machine
From the Action group of buttons, select Machine.
Click OK.
After generating the toolpath, the steep and shallow toolpath now machines the fillet with better toolpath confinement.
In the example below, the part is held by screws for certain operations. When the operations are complete and the screws no longer needed, they can be removed from the physical part. Instead of editing the design to remove the screws, you can specify the screws as surfaces or bodies to Gouge, which means the tool pretends as if they are no longer there and can go through them if they are in the tool's path.
Screws to hold a part
In the operation dialog, go to the Geometry tab.
In the Avoid/Machine Surfaces group, click to add a surface group. The Faces dialog opens.
With the Selection button active, from the Browser, select the bodies that the tool can gouge.
Selecting bodies to gouge
From the Action group of buttons, select Gouge.
Click OK.
After generating the toolpath, you can see that the toolpath now cuts the face and ignores/gouges the screws.
Tool gouges screws
In the example below, a part is held by a fixture but the toolpath is on the part and the fixture. To avoid machining the fixture, you can select the fixture surfaces and set the action to Fixture, which avoids the fixture by the specified clearances.
You can specify fixture surfaces in the Setup dialog or in the Avoid/machine surfaces group. If you specify fixture surfaces in the Setup dialog, the fixture surfaces are automatically added to the Avoid/Machine Surfaces group in the Geometry tab. If you did not specify fixture surfaces in the Setup dialog, you can add them in the Geometry tab.
In the Setup dialog, with the Fixture button active, select the bodies that make up the fixture.
Selecting fixture bodies
Specify a fixture Radial Clearance and an Axial Clearance then click OK.
Create a new toolpath and then go to the Geometry tab.
In the Avoid/Machine Surfaces group, because you specified the fixture in the Setup dialog, a fixture surface group appears automatically.
If you did not specify any fixture surfaces in the setup, click to add a fixture surface group. The Faces dialog opens to let you select fixture surfaces.
Specify any additional Radial and Axial fixture clearances.
Click OK.
After generating the toolpath, you can see that the flat toolpath now machines the part and avoids the fixture by the specified clearances.