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Lace Cut Options Tab gibbscam

The Options tab is enabled when the Lace Cut option is selected. It contains more detailed cut, stepover and retract options as well as controls for how to work with the edge of the part or selection.


Lace Cut Options

The three options for lace cuts are Constant Z Rough, Cut Surfaces; Z Surfaces Offset Rough; and One Finish Pass on Surfaces. Two of the options contain variations; each generates a different type of lace cut toolpath. The first two are designed to create roughing and semi-roughing surfacing toolpaths. The last (finishing pass) option allows users to designate only certain portions of the selected surfaces to be cut/finished. Each type of lace cut is described below. There are also example toolpaths for each of the lace cut options. These pictures are shown from the side view.

Constant Z Rough, Cut Surfaces

When this option is selected, the toolpath will cut along all surfaces that are part of the selected cut shape and that lie within the stock boundary. The system will first calculate the pass at the lowest Z depth specified by the Max. Z and create any subsequent passes up from there. No pass will be created above the Surface Z. Each pass will only cut surfaces not machined by previous passes in Z. When a portion of the surface that has already been machined by a previous pass is encountered, the tool will retract and move to any other surfaces that need to be machined at that Z depth. Each pass always steps down a fixed amount in Z.


Constant Z Rough, Cut Surfaces

Z Surface Offset Rough

This lace cut option creates a toolpath that repeats the finished toolpath (toolpath at final Z depth) up in Z. The final toolpath gets shifted up in Z by the desired Z Step, cutting off the pass when it hits the surface Z. The tool does not retract as it does with the Z Surface Offset Rough option; everything is cut. The tool rapids when outside the material, so the tool will plunge frequently. This option works best on gently undulating shapes. Constant Z Shift exactly duplicates the finished toolpath up in Z and retracts when it hits the surface Z. Constant # of passes breaks up any area that needs to be cut into the specified number of passes and then creates a step by connecting all of the passes. Each pass is a different shape; in addition, each pass cuts over the entire cut shape. There are no retract moves, as each pass cuts the entire part.

1. Constant Z Shifts
2. Constant # of Passes

Z Surfaces Offset Rough, Constant Z Shift

One Finish Pass on Surfaces

This lace cut option creates a toolpath that does not make any steps down in Z. The tool will only take one finishing pass over surfaces at the max Z depth. The different options allow users to control the surfaces that will be machined by the toolpath without having to select faces or designate constraints.

All Surfaces

With the All Surfaces option, the toolpath will machine all surfaces on the model at the Z depth entered for the Max Z that lie within the stock boundaries.

Normal Vector Constraint

This option is a process used to limit the area to be machined for a finish pass. Normal Vector Constraint specifies that toolpath will only be generated in areas where a surface is perpendicular to the tool within a given angular tolerance. The Normal Angle specifies this tolerance.


Top Down to Normal Angle vs. Ridge Cleanup.

Top Down to Normal Angle

This will calculate this area from the top of a part. The normal vector of the area cut is effectively less than the Normal Angle value. This is useful for cleaning up where large ridges have been left by flat or bullnose endmills.

Ridge Cleanup

Ridge Cleanup is designed to work opposite from Top Down to Normal Angle. The toolpath generated by Ridge Cleanup is limited to surfaces whose normal vector is greater than the Normal Angle.

Ridge Cleanup toolpath illustrates how Ridge Cleanup should be used and the results. The previous operation left ridges on the sides of the sphere. The cut direction for the Ridge Cleanup is perpendicular to the previous operation. When rendered, the sphere is much smoother.


Ridge Cleanup toolpath

Normal Angle

The Normal angle specifies the angle toolpath will only be generated in areas where a surface is perpendicular to the angular tolerance set. For instance, if a value of 45 is entered as the Normal Angle value, the toolpath will be confined to areas of the part where the surface of the part is up to and including 45° off of perpendicular from the tool.

Cut over Edges

When this option is enabled, all generated toolpath will automatically cut past all mixed edges on a part (a mixed edge is the edge between a selected and unselected face). This option is off by default.

Skip Flats

By default, toolpath is created that will machine the flat (perfectly horizontal) sections. Skip Flats will generate toolpath that will only follow the desired Z Step or Ridge Height.

Stepover Retract Options

These options only affect retract on the stepover moves of lace cuts; they determine how the tool will handle the stepover move between cuts.

On Every Stepover Move

This option will have the tool retract on every stepover move between cuts.

1. Machined Surface
2. Toolpath
3. Cut Width
4. Stepover Move

Stepover retract

On Long Stepover Moves

This feature provides for gouge protection when machining surfaces. If the ratio between the stepover move and the cut width (Stepover/Cut Width) is greater than the value entered for the Step/Cut Ratio, the system will retract for the stepover move. A larger ratio value will create fewer retract moves, while a smaller value will produce more retract moves. The default value of 2.5 is recommended to provide for the most efficient machining while still sustaining an adequate level of gouge protection.

No Retracts

A retract will not occur on stepover moves when the No Retract option is selected.

Toolpath Options

Stay In Stock

If Stay In Stock is checked, the toolpath will remain confined to the stock boundary, even if the selected face or body goes beyond the defined stock. This option is off by default so the toolpath will cover the entire selected body or face. Passes above the stock will be omitted but passes below the stock will be made to the final Z depth.

Clear Stock

This option will cause the toolpath to go beyond the bounds of the selected body or face in order to clear out the stock. The toolpath will only go as far as the Finish Z depth. Clear Stock functions in one of two ways, either

To Stock Edge

To Stock Edge will cause the toolpath to cut over the edge of the stock by the tool’s radius.

Past Stock

Past Stock will cause the toolpath to fully clear the stock, extending the toolpath beyond the stock’s edge by the tool’s diameter.

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