Producing Precise Simultaneous 5 Axis Toolpaths Intelligently.

The Tilt Tool Axis command in NX CAM offers a powerful solution for enhancing productivity in 5-axis machining while simplifying programming challenges. This feature enables CAM programmers to generate standard tool paths then seamlessly transition to 5-axis operations, decreasing CAM time an increasing program quality. Automatically after selected, Tilt Tool Axis proactively detects potential tool shank and holder collisions during machining operations. When a collision is anticipated, NX intelligently tilts the tool axis away from the obstruction, ensuring a smooth, uninterrupted milling process. For more control over your toolpath, use User Defined Tilting methods - optimization strategies for concave/convex features, strategies for full 5 Axis and positional “+” axis operations, motion limits to match your machine’s swinging/tilting range and avoid complications likely to produce undesirable results. Tilt Tool Axis is here for a quick, safe tool path or to fully describe the behavior of your 5 Axis Operation.

First, Specify the Part in Workpiece Geometry.

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Next, add a Mill Area Geometry as child of Workpiece and select the Cut Area.

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Create an operation.

Contour Area, from the mill_contour type will work well. Critically defined is a half inch ball mill, select OK.

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In the Non Cutting Moves Node, Engage group, set Open Area engage to Arc- Normal to Tool Axis.

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Select Generate.

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NX Operation Edit triggers a message box explaining that portions of the path have been trimmed for safety.

Select OK

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Visualization of the IPW and tool path confirm the error message. Much of the part was not cut due to the access limitations of the tool and 3 axis machining.

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Head to the Collision Check node, deselect the checkboxes of “Check Tool and Holder” and “Check for Non Cutting Collisions” then Generate.

When not minding collisions, NX generates a tool path over the entire Cut Area but there is clearly a collision between part and holder. While it is not safe, the base operation is prepared to be converted into a 5-axis path.

Now we will use the Tilt Tool Axis command in its simplest form to dynamically detect and minimally avoid tool holder collisions during the machining operation by tilting and rotating.

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RMB click the AREA_MILL operation -> Navigate to Tool Path -> Select Tilt Tool Axis

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The Tilt Tool Axis dialog box displays.

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Manual Tilting group is set to “Keep Original”.  Keep Original invokes NX CAMs automatic tool tilt as a reaction to tool holder collisions over challenging geometries. NX maintains the original tool axis orientation unless there is a predicted collision. As collisions are detected, NX tilts the tool minimally to maintain your holder clearance requirement and then returns the tool to the original tool axis orientation when possible.

Select the Collision Check/Avoidance tab. Note the Tool Holder clearance is inherited from the base operation. If you want to change the value, change it here so you don’t have to regenerate the base operation.

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Certain situations in the generation of simultaneous 5 axis toolpaths may cause a polar flip in CAM data expression and an abrupt 180-degree axis change in real life resulting in a tool/part collision.

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Expand the groups, in the Rotation Group change the Max Increase in Rotation and Max Decrease in Rotation to 1 to mitigate any radical changes in rotation. Further test indicated 10% rotation and 52.5% tilt max increase/decrease produced the best results.

Navigate to the Machine Characteristics tab and change the Max Step in Maximum Tool Axis Change from 30% Tool Diameter to 1% Tool Diameter. Set the Swing/Tilting Axis Limits for your machine.

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Max Tool axis change Max Step controls the linear distance, measured along the direction of the cut between two tool positions on the output path. These are the points where NX calculates the tilt angle. The default value is 30 percent of the tool diameter. A smaller step size creates more data points and NX adjusts the tool axis tilt more frequently to avoid collisions. A larger step size improves calculation speed. However, when the step size is too large, NX may not have enough data points to avoid collisions or provide a smooth path.

After successfully regenerating, NX Machine Tool Simulation reveals a safe and efficient 5 Axis Milling Operation!

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Let’s use an Away From Curve tool tilt method to exercise more control over the toolpath. First, regenerate the base operation. NX will display this message box, select Overwrite Path.

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Enter the Tilt Tool Axis dialog, Tilting tab and change Manual Tilting to User Defined.

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Select Tool Tilt Method Away From Curve.

Tool Tilt Methods Toward Curve/Away from Curve let you use a curve to control whether the top of the tool holder tilts toward or away from the guiding geometry. Away methods work better for normal to tool axis convex features.  Simply select a curve colinear to ZM+.

Shortest Distance creates a reference point on the selected guiding curve to generate the tilt plane. The reference point is the shortest distance from the tool position on the tool path. 2D projects the curve to a plane then creates vectors and is better suited for positional “+” axes programming. When Shortest Distance = 3D NX creates a vector in 3D space based on shortest distance and is best for simultaneous multi-axis solutions.

Select Shortest Distance 3D.

Set Tilt Rule to Away.

Tilt rule Away measures the tilt angle away from the line that intersects with the reference point on the selected guiding geometry toward the +ZM axis.

Tilt Angle is measured from the XM Axis. Set Tilt Angle to 55, targeting a 35-degree tilt from the tool axis.

Set the Swinging/Tilting Axis Limits for your machine then change Max Step to 1%. Then select OK.

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NX generates a tool path. Compared to Keep Original, our User Defined method has produced a consistent tilt away from the part at the top and bottom.

Machine Tool Simulation proves the toolpath to be safe.

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To dive deeper into the topic, check out this insightful video titled 'NX - Tilt Tool Axis':