Job assignment


The job assignment defines the surfaces and the areas of surfaces to be machined by an actual operation. Depending on the operation type, the job can be defined by different methods.

For the curve machining operations (such as 2D contouring, 3D curve milling), a job assignment can be defined by a set of curves, or groups that contain the curves, and also by points, that define circle centers. All geometrical objects of other types will be ignored. The tool toolpath will be created with regard to the user-defined options, e.g. tool offset left/right/centre from the curve. An additional stock can be added for every curve, as well as the operations stock. The stock amount will only be applied if the tool edge is touching the contour (left or right). When the tool travels along the centre of the curve then any stock values are ignored, and no offset toolpath is calculated.

In the engraving and pocketing operations, the job assignment is formed as an area at the top machining level. The area at the top machining level can be created from projections of curves onto the horizontal plane, any additional stock is also considered. Every curve can define either a ridge, ditch or an inversion curve, the thickness is defined by the additional stock value. Closed curves can also define a ledge, cavity or an inversion area, also considering the additional stock. Thus, the order that the objects appear in the list has considerably effect on the appearance of the resulting area. The toolpath is calculated so as to remove the workpiece material from outside of the model, taking into consideration any lateral angle applied for the operation.

For most of volume machining operations, the job assignment is defined by a set of solids, surfaces and mesh. The objects can be present in any combination and be grouped in an arbitrary way. All curves that are in the machining model will be ignored. When defining the job assignment, every geometrical object or its group can have an additional stock amount defined, which will be added to the operation stock. The tool toolpath is calculated to remove the workpiece material, which lies outside the job assignment, considering any stock amounts. This means that the tool will never cut the solids, surfaces or meshes that make up the job assignment.

The job assignment for the drive operations define a shape of the toolpath in the XY plane while the Z coordinate of the toolpath is calculated to guarantee the used tool touches the part.

The job assignment is formed from the curves projections onto the horizontal plane taking into account the prescribed stocks as well as the ways the actual curves (or curve groups) have to be included into the resulting area.

Each curve projection can form either a ridge or a ditch or an inversion curve whose width is determined by the specified stock. Further more, each curve projection can represent also a body, a hole and an inversion area. In those cases the specified stock is also taking into account. The objects are included into the resulting area by the order they are listed using Boolean operations. Thus the order the objects are listed has a great influence on the result. The way the tool will clear the resulting area itself is determined by the operation strategy.

If the job assignment for a drive operation is not specified then the system uses the part envelope as the job area.

The job assignment for turn operations introduces several ways to specify one ore more fragments of the turn generatrix of the part to be machined.

 

 

 

See also:

Defining part, workpiece and fixtures

Part