The Geodesic machining strategy is an advanced toolpath algorithm within RoboDK CAM designed for high-precision finishing. Unlike traditional methods that project 2D patterns onto 3D shapes, which often lead to distortion, the Geodesic strategy is calculated based on the true curvature of the workpiece. This makes it particularly effective for complex 3D geometries, including organic shapes and undercuts.

A geodesic distance is essentially the shortest path between two points on a surface. This strategy utilises a global calculation method that follows input (drive) curves and wraps the toolpath around the part while maintaining a constant stepover distance.

Why Use the Geodesic Strategy?

• High Surface Quality
  Ensures a superior finish by maintaining a constant cusp height for complex curvatures.
• Increased Efficiency
  Intelligent motion control minimises unnecessary ‘air cuts’ and optimises tool movement to shorten cycle times.
• Versatile Input Compatibility
  Uniquely accepts both parametric surfaces (mathematical CAD data) and mesh-based surfaces (such as STL scans).
• Automated Geometry Handling
  Adapts to freeform shapes, reducing the time spent on manual programming and path adjustments.
• Hardware Protection
  Constant tool engagement stabilises the cutting load, preserving the lifespan of both the cutters and the robot spindle.

Step-by-Step: Creating a Geodesic Project in RoboDK

Follow the below steps to configure a geodesic toolpath for machining in RoboDK.

1. Enable the RoboDK CAM Add-in

If the CAM interface is not visible, navigate to Tools ➜ Add-in Manager ➜ Plug-ins and enable RoboDK CAM. The CAM toolbar should appear below the main toolbar.

2. Set Up the Robotic Cell

Build a basic cell containing a robot arm and a reference frame to define the workpiece location. Import your CAD file and, optionally, a stock object. You can generate stock directly by right-clicking the part and selecting Generate Stock Geometry. A stock object improves toolpath accuracy and enables material removal simulation.

3. Configure the Cutting Tool

Open the Cutter Tool Library (first button on the CAM toolbar) to define your tool. Select a tool type (e.g. Sphere Mill) and specify the dimensions for the flute and shoulder. To ensure robust collision avoidance, add arbor and holder definitions. The cutter tool is automatically attached to the robot once defined.

4. Initialise the Geodesic Project

Select Geodesic from the CAM toolbar. You will need to define three geometry Features in the selection side-panel (double-click each to enable selection):

• Stock: Select the stock object (if applicable).
• Machining Surfaces: Select the specific faces to be machined.
• Part Surfaces: Optionally select the part surfaces for collision avoidance. This allows the algorithm to plan toolpaths without colliding into the part.

5. Adjust Parameters & Advanced Settings

For initial path generation, set Tolerance to 1mm and Stepover to 10mm (based on a 20mm mill) in Settings to reduce calculation time. For advanced options, click the Advanced button in Machining to access these key tabs:

Tool Axis Control
Align the tool orientation with your reference frame if needed.
Example: Tool axis will… ➜ Tilted with fixed angle to axis ➜ Z-axis

Gouge Check
Enable automatic collision avoidance for the tool.
Example: Activate Flute, Shaft, Arbor and Holder. Select Tilt tool ➜ Automatic as Strategy and click the … button to select safety surfaces as Check surfaces (#1) for collision checking.

Link
Choose Lead-in and Lead-out options to ensure smooth approach and retract moves when executing toolpaths.

Roughing
Enable Stock definition to compare stock with machining surfaces for toolpath generation and specify Depth Cuts to manage material removal layers.

Pro Tips

• CAM vs Robot Paths: Click Generate then Apply on the project’s CAM tab to show the machining toolpath. Navigate to the Robot tab to set up a Robot Machining Project in RoboDK with the generated path.
• CAM Settings: Access via the CAM menu. If you are working with large STL files or high-detail meshes, reduce the Surface tessellation tolerance to improve performance.
• Stock Object: Use the last button on the CAM toolbar to enable material removal simulation (Set Stock Object… turns the geometry cyan). You can also toggle the visibility of the stock object.

Conclusion

The Geodesic strategy in RoboDK CAM provides a mathematically driven solution for generating 3- to 5-axis toolpaths on complex 3D surfaces. By calculating paths based on the actual curvature of the part rather than 2D projections, it ensures a constant stepover and uniform material removal. The integrated features like Gouge Checking and Tool Axis Control allow for precise programming of industrial robots, for applications requiring high surface quality and automated collision avoidance. Follow the above guide to create your first Geodesic machining project in RoboDK!