3D Rough Toolpath

Rough Machining is used when carving 3D parts to clear away excess material when the part is too deep for the finishing tool to cut in a single pass.

Clicking on this icon opens the toolpath form shown to the right; the functions available within this are described below.

The machining limit boundary is the area in which the tool will operate. There are several options:

Model Boundary The combined boundaries of all the components in this job are used. This is the area of the composite model which has components on it. Note: this is not the boundary of the selected models.

Material Boundary The boundary of the entire material block is used.

Selected Vector(s) Selected vectors are used as the machining boundary.

Selected Level The combined boundaries of all the components on the specified level. This is similar to Model Boundary, but only specific to the named level.

The machining allowance is a virtual thickness which is added to the 3D model when the Roughing Toolpath is calculated. This ensures that the toolpath leaves some extra material on the roughed part.

This is beneficial for two main reasons, the first is that when roughing it tends to be done with relatively large tool and aggressive cuts and so is more prone (depending on the material) to chip, this skin helps to prevent the chipping affect the finished surface. The second reason is that most tools cut well when they are constantly removing material. Therefore leaving an allowance of material on ensures that there is always at least some material for the finishing toolpath to remove.

Z Level Roughing essentially uses a series of 2D Pocket toolpaths which take into account the 3D model and hog-out the material around it within the specified boundary.

The first setting is the choice of Profile, this controls whether each level has a profile cut around its boundary or not and if so whether it cuts before the raster or after it. First does the profile before the Raster on each level, Last does the profile cut after the raster and None eliminates the Profile cut leaving only the raster pattern. These choices depend a lot on the material and tooling being used. For example, more brittle material may benefit from the profile first option to reduce chipping.

The second setting is the choice of Order. The Z Level can be performed in Level by level manner. This means to generate a complete pass at a given depth over the whole model, before advancing to the next level. This is the default option.

The user can also select Depth-first. In this case if at a given depth the model consists of separate regions, the generated toolpath will generate all passes at increasing depths over such region. Then it will advance to another such region.

By default, when using raster direction Along X the tool will move from one raster line to another from bottom to top. In case of raster direction Along Y the tool will move from right to left. This option allows to reverse that stepover direction.