How to Configure Cutting Tools in FreeCAD Path

This guide explains the function of Tool Controllers in FreeCAD's Path (CAM) workbench and details how to define, configure, and assign cutting tools for CNC machining projects. You will learn the difference between physical tool geometry and operational cutting parameters, followed by a step-by-step procedure to set up tools, feeds, and speeds inside your machining jobs.

What is a Tool Controller?

In FreeCAD Path, a Tool Controller acts as the operational bridge between a physical cutting tool (a ToolBit) and a machining operation. While a ToolBit defines only the physical dimensions of the cutter—such as diameter, flute length, and tool shape—the Tool Controller defines how that tool is run during a specific job.

This separation allows you to use a single physical tool under multiple conditions. For example, a 6mm flat endmill can have one Tool Controller configured with aggressive feeds and speeds for roughing, and another Tool Controller configured with slower feeds for fine finishing, or different settings tailored for cutting aluminum versus wood.

Understanding ToolBits and the ToolBit Library

FreeCAD uses a modern system called ToolBits to store tool geometry:

  • Shapes: Parametric models (e.g., endmill, ballnose, v-bit) defining the cutter's profile.
  • ToolBits: Specific instances of a shape with set dimensions (e.g., a 1/4" flat endmill with a 20mm cutting edge).
  • ToolBit Libraries: Collections of ToolBits organized into directories or projects.

Step-by-Step: Creating and Configuring a Tool

1. Create a New ToolBit

  1. Switch to the Path (or CAM) workbench in FreeCAD.
  2. Open the ToolBit Dock via the menu: CAM > ToolBit Dock (or click the ToolBit Library Manager icon).
  3. Click the Create ToolBit button.
  4. Select a template shape that matches your cutter (such as endmill.fcstd).
  5. Enter a clear name for the tool (e.g., 6mm_2Flute_FlatEndmill).
  6. Adjust the geometric properties in the property panel:
    • Diameter: The outer cutting diameter.
    • CuttingEdgeHeight: The length of the flutes.
    • Length: The overall extension of the tool from the collet.
    • Flutes: Number of flutes (used for chip load calculations).
  7. Save the ToolBit to your local library.

2. Add the Tool to a Job via a Tool Controller

  1. Create or open a Path Job (CAM > Job).
  2. In the Job Edit dialog, navigate to the Tools tab.
  3. Click Add to browse your ToolBit Library.
  4. Select the ToolBit you created and confirm. FreeCAD will automatically generate a Tool Controller for this tool inside your Job tree.

3. Configure Machining Parameters in the Tool Controller

Once the Tool Controller is added to your job:

  1. Double-click the newly created Tool Controller in the Model tree (located under your Job).
  2. Set the operational machining parameters:
    • Spindle Speed: The rotational speed in RPM.
    • Spindle Direction: Forward (clockwise) or Reverse.
    • Horizontal Feed (Feed Rate): The speed at which the tool moves across the X/Y plane during cutting moves.
    • Vertical Feed (Plunge Rate): The speed at which the tool moves downward into the material along the Z-axis.
    • Tool Number: The slot number corresponding to your CNC machine's automatic tool changer (ATC) or manual tool-change routine.
  3. Click OK to save the settings.

Assigning Tool Controllers to Operations

When you create a machining operation (such as Profile, Pocket Shape, or Adaptive):

  1. Open the operation settings panel.
  2. In the Tool Controller drop-down menu, select the configured controller for the task.
  3. The operation will inherit the feeds, speeds, and tool geometry specified by that controller, ensuring the generated G-code accurately reflects your cutting parameters.