Toolpath control with boundaries

HSM Performance Pack includes several options for controlling the containment of a tool’s motion during machining. Useful for gaining more control over the toolpath by limiting machining to a confined area within a boundary – and for controlling exactly how close to the boundary a tool is allowed to cut.

Boundary options in HSM Performance Pack include Machining, Contact an Stock boundaries which are supported by most of our strategies. However, the availability of these depends on the nature of the specific strategy being used. In the following we will have a closer look at these options.

For examples of using boundaries in HSM Performance Pack, please look at our demo part “Boundaries”.

As an example, the screenshot below shows the options available for our Parallel finishing strategy. Under the Geometry tab, a Boundary has been added in the “Boundaries and Points” section and the type of tool containment within this boundary is being set to Contact. Notice the options “Tool containment” which lets you control whether the tool is restricted to the inside of the boundary, can move to the center or move outside the boundary. This option is only relevant to Machining boundaries.

Machining boundaries

Machining boundaries enable you to restrict the tool to the inside, center or outside of selected boundaries by taking into consideration the radius of the currently active tool. Contours, that are selected as Machining boundaries, are not allowed to intersect and will cause an error.

Options for Tool containment include:

1) Inside: Keeps the entire tool (center + radius) inside boundaries
2) Center: Allows the center of the tool to move to boundaries
3) Outside: Allows the tool to move outside boundaries by a distance of the tool’s radius
4) Additional offset: Offsets the tool from boundaries by a distance. Positive value for outside and negative for inside

The offset value applies to all selected Machining boundaries and generates new, intersection free boundaries.

For roughing strategies, the selected boundaries are applied to the cutting passes which avoids having to use trimming and guaranties that any linking moves are also kept within boundaries.

For finishing strategies, cutting passes are trimmed against boundaries which ensures cutting passes are kept inside boundaries but linking moves might still be outside. Some finishing strategies further include the option “Follow containment” which forces HSM Performance Pack to apply boundaries to the cutting passes and ensure linking moves are kept within boundaries – similar to boundaries for roughing strategies.

Contact boundaries

Contact boundaries are used to ensure that the contact point between tool and surface are kept inside the selected boundaries. The main difference between Machining and Contact boundaries is that Contact boundaries lets you control the tool’s touch positions. Contact boundaries are primarily available and used with finishing strategies. However, the Horizontal strategy does not support Contact boundaries.

In the image above the red point indicates the contact point with the surface. The green point indicates the tool tip.

Please note that “Tool containment”, described above, does not apply to Contact boundaries.

Stock boundaries

Stock boundaries are normally used when specifying stock for roughing strategies with the option “Machining from outside” enabled, but it is also supported by the Horizontal strategy. It works similar to Rest machining and ensures that only cutting passes that touch the stock are kept which also avoids air cuts.

Please note that “Tool containment”, described above, does not apply to Stock boundaries.