How to Set Up Profile Cutting in FreeCAD Path

This guide provides a straightforward walkthrough on setting up a 2D profile cutting operation using the Path (CAM) workbench in FreeCAD. You will learn how to create a machining job, assign your cutting tool, select the appropriate model geometry, configure critical depth and offset parameters, and verify the generated toolpath before exporting your final G-code.

Step 1: Switch to the CAM Workbench and Create a Job

  1. Open your 3D model in FreeCAD.
  2. In the workbench dropdown menu, select CAM (formerly named Path in older versions).
  3. Click the Job icon on the toolbar to create a new machining setup.
  4. In the Job dialog:
    • Model: Ensure your solid body is selected.
    • Output: Specify your post-processor based on your CNC controller (e.g., GRBL, LinuxCNC, Mach3).
    • Setup Sheet: Adjust stock dimensions if you need extra stock allowance around the part.
    • Tools: Add a suitable tool controller (e.g., an end mill with appropriate feed rates and spindle speeds).
  5. Click OK to generate the Job object in the tree view.

Step 2: Select Geometry

  1. Click on the 3D model to select the edges or faces defining the profile you want to cut.
    • To cut around the perimeter, select the bottom face of the part, or select the continuous loop of outer edges while holding the Ctrl key.
    • For an interior cutout (pocket hole profile), select the bottom face or inner loop of the hole.

Step 3: Insert the Profile Operation

  1. With the geometry selected, click the Profile tool icon (Profile based on edges or a face) on the CAM toolbar, or go to CAM > Profile.
  2. The Profile task panel will open on the left.

Step 4: Configure Profile Parameters

Navigate through the tabs in the task panel to configure your cut:

  • Base Geometry: Verify that the correct edges or faces appear in the list. You can use the Add or Remove buttons to adjust selections.
  • Depths:
    • Start Depth: The top surface of your cut (typically 0 mm or the top of the stock).
    • Final Depth: The bottom of the cut (e.g., the part thickness or slightly deeper if through-cutting into a spoilboard).
    • Step Down: The maximum depth per pass. FreeCAD will divide the total depth into equal steps based on this value.
  • Heights:
    • Clearance Height: The Z-height for rapid travel between cut locations.
    • Safe Height: The transition height before plunging into the cut.
  • Operation:
    • Side: Choose Outside for exterior profiles or Inside for interior cutouts.
    • Direction: Set to CW (Clockwise) or CCW (Counter-Clockwise) to enforce climb or conventional milling, depending on your material and tooling.
    • Use Compensation: Check this box if you want the tool radius offset calculated automatically.

Click Apply, then OK to generate the profile toolpath.

Step 5: Simulate and Verify

  1. Select the newly created Profile operation under your Job in the tree view.
  2. Click the CAM Simulator button to watch the toolpath preview.
  3. Verify that the tool cuts on the correct side of the line and steps down in appropriate increments without gouging the finished part.

Step 6: Post-Process (Export G-code)

  1. Select the main Job object in the tree view.
  2. Click the Post-Process button on the toolbar.
  3. Choose a destination folder and filename, then click Save to write the G-code file for your machine.