CR Touch and BLTouch: Introduction, Comparison, Reset and Repair

Auto-leveling systems that are widely used in 3D printing include CR Touch and BLTouch. They detect the bed surface before each print and then adjust the nozzle height to account for any bed unevenness. While they are very useful, sometimes these systems fail when homing, resulting in print-related issues such as layer shift and poor bed surface adhesion and blTouch's inability to verify sensor status. Next, I will give you an in-depth explanation and comparison of CR Touch and BLTouch. We hope it will be helpful to your 3D printing!

What is a BL and CR Touch sensor?

The BLTouch sensor is a critical 3D printer sensor used for automatic leveling. The mechanism involves using a probe to make contact with the bed surface at various points to obtain an accurate map of the surface. This map guides Z-axis alignment during the printing process, ensuring proper bed surface adhesion.

BLTouch 3D Printer Sensor Kit

Similarly, CR Touch sensors are used for automatic leveling, but use a different sensor type. The CR Touch sensor creates an accurate contour map at several points by pressing a metal pin against the bed surface. This data guides how the Z-axis adjustment should be adjusted during printing to ensure optimal bed adhesion for the print.

CR Touch Auto-Leveling Sensor Kit

Compare Cr Touch and Bltouch

Is the CR Touch BETTER than the BL Touch? What are the Differences between the CRTouch and the BL Touch.

The CR Touch and BLTouch are both popular auto-leveling sensors used in 3D printing to ensure that the print bed is level and at the correct distance from the print nozzle. While they serve a similar purpose, there are some differences between the two:

Cr Touch vs Bltouch

Feature	CR Touch	BLTouch (Bilby 3D Touch)
Type	The CR Touch is also a contact-based sensor with a small pin or probe that touches the bed's surface to measure the distance.	The BLTouch is a contact-based sensor. It uses a small pin (probe) that physically touches the print bed's surface to measure the distance.
Operation	Like the BLTouch, the CR Touch deploys its probe and makes contact with the bed at multiple points to measure the bed's tilt and compensate for it.	The BLTouch extends its probe and makes contact with multiple points on the bed's surface to create a detailed mesh of the bed's contours. It's known for its accuracy.
Wiring	The CR Touch typically has fewer wires than the BLTouch, which can make installation easier for some users.	BLTouch sensors typically require a minimum of 5 wires for connections: ground, power, control, and two additional wires for the servo motor that controls the probe.
Compatibility	It is specifically designed for Creality 3D printers, which means it may have better out-of-the-box compatibility with Creality printer models.	BLTouch sensors are compatible with a wide range of 3D printers and are well-supported in various firmware configurations.
Price	The CR Touch is often seen as a more budget-friendly option, especially for users with Creality printers.	BLTouch sensors tend to be slightly more expensive compared to some alternatives.
Accuracy	Good	Excellent
Ease of Installation	Easier for Creality printer users	May require more configuration for some

What is the Reason why CR Touch and BLTouch cannot be reset?

There are four main reasons why CR Touch and BLTouch sensors may not home properly:

1. Wiring errors: Loose or damaged wiring may cause the sensor to malfunction and fail to return to its correct position.

2. Inaccurate sensor position: The correct position of the sensor is very important for accurately measuring the bed surface, otherwise it may cause homing problems.

3. Sensor failure: The sensor itself may fail due to damage or wear.

4. Bed surface problems: If the bed surface is uneven or unclean, the sensor may not be able to obtain accurate readings, resulting in homing errors.

Why Bltouch Failed to Verify Sensor State

The "BLTouch failed to verify sensor state" error typically occurs when the BLTouch probe is unable to perform its self-test successfully during the printer's startup or initialization process. This issue can be caused by several factors, it is usually caused by wiring problems, power supply voltage problems or connector problems. And troubleshooting it may require some investigation. Here are some common reasons for this error and potential solutions:

1. Wiring Issues

Check the wiring connections between the BLTouch and your 3D printer's control board. Ensure that all connections are secure and correctly positioned. Verify that the wire colors match the correct pins on both ends (BLTouch and control board).

If the wiring is incorrect or the settings are configured incorrectly, BLTouch may not be able to verify sensor status.

2. Power Supply

Ensure that the BLTouch is receiving the correct voltage from the control board. It usually operates on 5V or 3.3V, depending on the model.

Check for any loose or damaged wires that may affect the power supply.

3. Firmware Configuration

Review your 3D printer's firmware configuration to confirm that it is set up to use a BLTouch. Check the pins, probe type, and other BLTouch-related settings.

Update or reflash the firmware if necessary, ensuring it is compatible with the BLTouch model you have.

4. Physical Issues

Inspect the BLTouch probe itself for any physical damage, such as bent pins or a misaligned probe.

Ensure that the BLTouch can move freely up and down without obstruction.

5. Connector Issues

If you have a detachable connector for your BLTouch, make sure it's securely plugged into the BLTouch module.

6. Mounting and Bed Leveling

Ensure that the BLTouch probe is properly mounted and aligned with the nozzle. An improper alignment can lead to verification errors.

Verify that your printer's bed is level and properly adjusted.

If you are sure that your BL-Touch is wired correctly and it reports "BLTouch cannot verify sensor status" every time you try to probe with BL-Touch, you may want to add to the bltouch configuration section pin_up_touch_mode_reports_triggered: False. BL-Touch v3 and many clones require this setting.

Conclusion

Both CR Touch and BLTouch offer valuable solutions for 3D printer bed leveling. Your choice should depend on your specific needs, experience level, and the compatibility of the sensor with your printer. Remember to handle and maintain these sensors with care to ensure long-lasting, accurate bed leveling for your 3D printing projects.