How to Properly Set and Adjust a CNC Tool Height Sensor for Accurate Calibration

Category: How-To Guides & Tutorials

Properly setting and adjusting the tool height sensor is essential for precise and efficient CNC routing. This guide will walk you through the key steps to ensure an accurate setup, helping you save time and improve machining results.

How the Tool Height Sensor Works

A tool height sensor is designed for automatic calibration of tool length and measurement of workpiece thickness. It is especially useful when:

• Frequently switching between different material types.

• Using an automatic tool changer (ATC) system.

Basic Working Principle

The tool height sensor operates based on circuit closure:

1. The sensor consists of a spring-loaded contact surface (usually a button-like component).

2. When the CNC machine initiates a tool measurement, the Z-axis lowers until the tool touches the sensor.

3. The machine then records the sensor height, tool position, and material thickness.

Example Calculation

If the sensor is 50 mm tall and the tool touches it at a Z-coordinate of 150 mm, the machine calculates the material thickness as:

150 mm (Z position) - 50 mm (sensor height) = 100 mm (material thickness)

This automated measurement eliminates human error and speeds up the setup process!

Tool Height Sensor Setup Menu

To configure the tool height sensor, navigate to:
📌 Menu > Machine Setup > ToolSet Setup

Here, you’ll find four key sections to configure:

1. Position

• If the menu displays “In Plc”, it means the tool sensor does not have a fixed position and can be placed anywhere within the working zone.

2. Thickness

• This section stores the height of the sensor itself.

• How to measure sensor thickness:

  1. Use a caliper to measure the exact height of the tool sensor.

  2. Round off the value if necessary.

  3. Enter the measurement in the setup menu (e.g., 40.4 mm).

3. Pickup (Bounce Height)

• This setting defines how high the spindle will lift after touching the sensor.

4. Speed

• Controls the speed of tool measurement for a balance between precision and efficiency.

Step-by-Step Setup Process

Step 1: Place the Tool Height Sensor

• Position the sensor on the worktable.

Step 2: Start Calibration

• Press “On-Off” + “Menu” to begin the measurement process.

Step 3: Verify the Measurement

• Switch to slow mode and manually lower the tool toward the material until it reaches point zero.

• If the tool does not exactly touch the material, perform fine-tuning adjustments:

  • Lower the tool in 0.1 mm steps until it makes slight contact.

Step 4: Adjust Sensor Height

• If an adjustment is needed, go to:
  📌 Machine Setup > ToolSet Setup > Sensor Thickness

• Modify the sensor height setting:

  • Example: If you measured 40.4 mm but found the tool is 0.4 mm too high, update the setting to 40.8 mm.

• Confirm the change and repeat calibration.

Step 5: Final Verification

• After calibration, the tool should accurately touch the material at point zero.

Key Benefits of Using a Tool Height Sensor

✅ Ensures Accuracy – Provides precise tool length and material thickness measurements.
✅ Saves Time – Automates calibration, making it faster to switch materials and tools.
✅ Essential for ATC Systems – Works seamlessly with automatic tool changers.
✅ User-Friendly Design – Some CNC machines include built-in storage pockets for easy sensor access.

Conclusion

1️⃣ Accurate Calibration is Essential – Proper setup directly affects machining precision.
2️⃣ Time-Saving Automation – The tool height sensor significantly reduces manual work.
3️⃣ Step-by-Step Configuration Matters – Adjusting sensor thickness, bounce height, and speed ensures optimal performance.
4️⃣ Regular Testing Improves Accuracy – Verifying and fine-tuning the settings minimizes errors.

By following these steps, you can maximize the efficiency and accuracy of your CNC router’s tool height sensor!