Hatch and Island Fill Toolpaths

 Hatch Fill

 Island Fill

Generate toolpaths for milling large areas.

Hatch vs Island Fill

Efficiency and surface finish are the two most important considerations when choosing between hatch and island fills. Generally when cutting a large area the hatch fill will be the most efficient. If a design is made up of long, thin sections, the island fill will be the most efficient. Both methods leave a distinctive surface after milling and if the surface finish of the final design is important, it could drive which method to use.

Types of Cuts

There are three types of cuts that can be defined in a Hatch Fill strategy: Fill Cut, Fine Cut, and Clean Cut.

Fill Cut Define the tool to perform the Hatch Fill.
Fine Cut -(optional) A tool with a smaller diameter than the Fill Cut that fits into corners and thin areas too small for the Fill tool. The amount of overlap between the fine cut and adjacent toolpaths must be specified.
Clean Cut - (optional) Define a tool that generates toolpaths offset from the contours to improve the finished edge of the design or to utilize a 3D engraving toolpath.

The image below illustrates a hatch fill strategy with a fill cut and 3D engrave clean cut.

Strategy Parameters


Defines if the strategy will be used as the female part of an inlay project.  The toolpath must compensate for the tool dimensions and account for an inlay gap, which is the spacing between the male and female portions of the inlay. The images on the left below show toolpaths without with out inlay and the images on the right have inlay applied and highlight how the toolpaths are modified in the corners.






There are three different options for how the hatch fill cuts the contour.

Standard Minimize the number of tool lifts, do not allow the hatch toolpath to pass over any part of the hatch area more than once, and enforce a strict back-and-forth pattern across the cut area
Nose Cone Generate hatch toolpaths for compatibility with a Nose Cone engraving tool. Maintain an edge of uncut material next to the nose cone to maintain a constant cut depth.
None Cut the cleaning pass before the associated fill cut.

Hatch Fill Cut Parameters

Hatch Fill toolpaths use the common Cut Parameters . A couple of unique parameters to control the Fill.

Overlap Define the overlap percentage between adjacent toolpaths. Valid values range from 0-99 with a default of 50. A general rule of thumb is that softer materials require less overlap and harder materials require more overlap. This value can also be changed to achieve a desired surface effect.
Hatch Angle Define the angle with respect to horizontal that the toolpaths will be generated at. A hatch angle of 0 degrees will generate a horizontal fill pattern and 90 will generate a vertical fill.

Island Fill Cut Parameters

Island Fill toolpaths use the common Cut Parameters. A Corner Tag parameter defines if additional toolpaths will be generated in corners. Corner tags are important when the overlap is set to less than 50 percent to ensure the entire area is milled. The images below show a star contour on the left with corner tags, and on the right without.

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