How to Install BLTouch Sensor in Ender-3 V2 for Auto Bed Leveling

If your 3D printer bed is not correctly leveled, you've got a problem.

One of the most important but frustrating parts of a 3D printer is bed leveling. If the bed is not properly leveled, the first layer will not stick to the printer bed, and you will end up with a mess. But unfortunately, almost all budget 3D printers come with manual bed leveling, mostly with 4 point bed system, requiring you to adjust the bed level from the printer nozzle.

And boy, it’s a never-ending process.

If you raise or move down the bed even a millimeter from one corner, it affects the adjacent corner and vice-versa. Thus, it requires constant adjustment, and believe me; it’s the most annoying part of using a 3D printer.

Automating Bed Leveling with BLTouch Sensor

BLTouch is a must-have 3D printer upgrade when you buy any budget 3D printer. It is a magnetic hall sensor installed on supported printers, such as the Ender-3 V2, to automate the bed leveling. It is attached to the nozzle and has a probe that physically touches the bed to check the bed height on the Z-axis with a series of coordinates. It creates a mesh offset (usually 3x3 or 4x4 or 5x5) based on the bed size.

The sensor can precisely measure the bed tilt at all corners and coordinates to adjust accordingly next time when you print any object. This helps ensure your prints stick properly to the bed and does not move or get messed up. The sensor can be installed on any printer, and it works on all types of 3D printer beds, such as wood, metal, glass, etc.

Installing BLTouch Sensor on Ender-3 V2

Although installing and configuring the BLTouch sensor is a tedious job, it requires a one-time setup to free you from worrying about bed leveling. Below are the steps you can follow to install and set up the BLTouch sensor on Ender-3 V2 or any 3D printer that supports the BLTouch sensor by default or through a firmware update.

Step 1: Print the BLTouch Sensor Mount for Your 3D Printer

The 3D printed mount varies based on the printer model. Download the BLTouch mount STL file for Ender-3 V2 on your system and print the mount required to attach the BLTouch sensor to the printer nozzle.

If you own a different 3D printer, check out Thingiverse for the compatible mount, or you may take the matter into your own hands and design one for your printer.

Step 2: Mount the BLTouch Sensor to the Nozzle

The BLTouch Sensor comes with mounting screws to attach it beside the printer nozzle with the help of the 3D printed mount. Use them to connect the BLTouch to the side of the printer nozzle, as shown below.

Step 3: Connect the BLTouch Sensor Wires to the Motherboard

BLTouch sensor also comes with 1000mm long wires to connect it to the printer motherboard. Use them to connect the BLTouch sensor to the motherboard.

Take special attention to the pins. If you connect them wrong, it may damage the sensor.

BLTouch Ender-3 V2 Motherboard GND G VDD V SIG IN GND G ZMIN OUT

Step 4: Download and Flash the Firmware with BLTouch Sensor Support

To flash the firmware, you need to download it from the official website. For Ender-3 V2, flash Jyers firmware available on Github for Ender-3 V2 with BLTouch and Filament sensor support.

After the download, paste the firmware on the root of your printer SD card and then connect it to the printer. Make sure the printer is off when you insert the SD card.

Switch on the printer. This will flash the firmware in 15-20 seconds. After the flash, the display will turn on and preview all the options, including the new option called Level.

Step 5: Remove Z-Axis Stop Switch

You no longer need the z-axis switch and thus, can remove it. Unplug the connector and then unscrew the T-nuts to remove the z-axis switch from the printer.

Step 6: Calibrate the BLTouch Sensor

Calibration is the most important part of the BLTouch sensor installation. Follow these steps to calibrate the sensor.

1. Go to Prepare> Move and select 0.0 mm in Move Z
2. Then go back and enable Live Adjustment.
3. Select Z-Offset and then choose a value around 0.22 mm
4. Take a piece of paper and put it below the printer nozzle

Once this is done, slide the paper it back and forth and simultaneously use the Microstep Down or Microstep Up option in the printer UI to move the nozzle (z-axis) up and down by 0.01 mm. Keep moving the paper until you feel the scratch.

Once you have found the right negative value for Z-offset, move down and select Save.

Step 6: Make Changes to Cura or Creality Slicer

Cura and Creality are the default slicer software suites used by most users. If you use Cura, Creality, or any other 3D printer slicer, you must enable the auto-homing and auto-bed leveling using BLTouch by adding two lines of code in your printer's start G-code.

This is a straightforward process. Open the Cura or Creality slicer and go to your printer, click Manage Printers.

Click Machine Settings and add the following lines as shown in the image.

G28 ; Home all axes
G29 ; Level bed

Click Close and Close again.

And that’s all you need to do. You’ve now successfully installed a BLTouch sensor on your Ender-3 V2.

Add a Filament Runout Sensor for Greater Peace of Mind

The firmware we installed on Ender-3 V2 also supports a filament runout sensor that you can install between the filament and extruder. This will prevent the printer from keep running unnecessarily if the filament roll gets empty or runs out during the print session. The sensor will send this information to the controller, which will pause the printing until the filament is provided or added.

You may either buy one from an online store (optical sensor) or build one by using a small mechanical switch and a 3D printed casing.