Installing a BLTouch sensor on the Creality K1 Max improves automatic leveling and ensures more precise print results, especially for large print models. The BLTouch is an automatic leveling sensor that measures the position of the build plate at multiple points and automatically adjusts the height of the print head. Retrofitting a BLTouch requires some mechanical adjustments, connecting to the mainboard, and firmware adjustments.

Here is a detailed step-by-step guide for retrofitting a BLTouch sensor on the Creality K1 Max.

Tools and materials

  • BLTouch sensor (e.g. from Antclabs)
  • Screwdriver set (flathead and Phillips screwdrivers)
  • Allen keys (usually 2 mm and 2.5 mm)
  • Screws and nuts (usually included with the BLTouch)
  • 3D-printed mount (for mounting the BLTouch on the print head)
  • Cable ties (for securing the cables)
  • Extension cable for BLTouch (optional, if the supplied cables are not long enough)
  • Computer with internet access for firmware customization

1. Preparation and safety

Before starting the installation, make sure the printer is turned off and unplugged to avoid accidents or damage to the electronics.

  • Turn off the printer and disconnect it from the power supply.
  • Let the printer cool down if it was recently used.

2. Create a 3D-printed mount for the BLTouch

Since the BLTouch sensor cannot be mounted by default on the Creality K1 Max, you need a special mount that places the BLTouch next to the nozzle.

  • Print the mount: On platforms like Thingiverse or Cults3D, you can find suitable mounts designed for the Creality K1 Max. Search for “BLTouch mount for Creality K1 Max” and print the mount with PLA or PETG.
  • Check the fit: Test the mount on the print head to ensure it fits and positions the BLTouch at the correct height.

3. Mounting the BLTouch sensor

After the mount is printed, you can attach the BLTouch sensor to it.

  • Attach the BLTouch: Secure the BLTouch sensor to the printed mount using the supplied screws. Make sure the BLTouch pin points downward and can move freely in and out.
  • Attach the mount to the print head: Mount the bracket with the BLTouch on the front or side of the print head (depending on the bracket design). Tighten the screws to ensure the mount remains stable during printing.

4. BLTouch wiring

The BLTouch has two main cable groups: one for power supply and one for the control signal. These must be connected to the printer's mainboard.

1. Routing cables

  • Route the BLTouch cable neatly along the printer frame and secure it with cable ties.
  • Avoid sharp corners or moving parts to prevent damage to the cable during printing.

2. Connection to the mainboard

  • Open the case of the mainboard by carefully removing the cover.
  • Connections for the BLTouch: On the Creality K1 Max board, there are special pins for installing an automatic leveling sensor (usually labeled as Z-Probe or Z-Endstop).
    • Control line: Connect the control line (usually a 3-pin connector) to the corresponding pins for the Z-Probe.
    • Power supply: Connect the 2-pin power cable of the BLTouch to the corresponding 5V and GND pins.

If the connector does not fit, you can use Dupont connectors or adapters.

5. Adjust firmware

After hardware installation, the firmware of the Creality K1 Max must be updated to support the BLTouch sensor.

1. Download Marlin firmware

  • Go to the Marlin firmware website and download the latest version.
  • Alternatively, you can download a customized version of the firmware that already supports the BLTouch.

2. Configure firmware

  • Open the configuration files (Configuration.h and Configuration_adv.h) of the Marlin firmware with a text editor or an IDE like VSCode with PlatformIO.

  • Search in the Configuration.h file for the line:

    #define BLTOUCH

    Make sure this line is not commented out so that the BLTouch is activated.

  • Also enable automatic bed leveling:

    #define AUTO_BED_LEVELING_BILINEAR

  • Disable Z-Endstop: Disable the mechanical Z-Endstop as the BLTouch now acts as the endstop.

    #define Z_MIN_ENDSTOP_INVERTING false

3. Compile and upload firmware

  • Compile the customized firmware in PlatformIO or a similar development environment.
  • Load the compiled Firmware.bin file onto an SD card and insert it into the printer.
  • Restart the printer to flash the new firmware.

6. Calibrating the BLTouch

After the firmware update, you need to calibrate the BLTouch to ensure the sensor works correctly.

1. Set Z-Offset

  • Perform a homing procedure via the printer menu to ensure the BLTouch correctly detects the zero point.
  • Use a feeler gauge or a sheet of paper to set the Z-offset. This ensures the correct distance between the nozzle and the build plate.
  • Save Z-Offset: Save the set Z-offset in the firmware so it is used every time the printer starts.

2. Test automatic leveling

  • Select the option for automatic bed leveling in your printer's menu.
  • The BLTouch now moves over several points of the build plate and measures the distance. This data is used to automatically adjust the print height.

7. Perform test print

After calibration, you should perform a test print to ensure the BLTouch is working correctly.

  • Print test file: Choose a simple test file (e.g., a calibration cube) and check if the layers are printed evenly and without adhesion issues.
  • Check results: Pay special attention to the first layer and the flatness of the print. If the print bed is evenly leveled at all points, the installation was successful.

Conclusion

Installing a BLTouch sensor on the Creality K1 Max is a worthwhile upgrade that significantly improves print quality through precise automatic leveling. With the right steps – from mounting and wiring to firmware adjustment – you can successfully install the BLTouch and automate the printing process. Regular calibration and test prints ensure your printer always delivers perfect first layers.