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Enhance your 3D printing experience with our comprehensive guide on installing a BLTouch auto bed leveling sensor on the Creality Ender 3. Auto bed leveling is an essential and low-cost upgrade that streamlines the bed leveling process, prevents bed adhesion issues, and improves print quality.
Our step-by-step instructions take you through the installation process, firmware update, and calibration settings, ensuring a smooth and successful upgrade for beginners and experienced users.
Turn off your 3D printer and unplug it from the power supply unit.
Remove the Z-axis limiter. You won’t need the limiter switch when you use the BLTouch kit for print bed leveling. (We’ll remove the wiring later.)
Connect the 5-pin connector to the BLTouch sensor. We recommend connecting the BLTouch before mounting. You may encounter clearance issues if you wait to connect the 5-pin BLTouch cable after mounting the sensor to the bracket. Note: Don’t force the connector onto the pins. Forcing the connection may damage the pins. If you are having difficulty, refer to the assembly diagrams for clarification.
Mount the BLTouch to the sensor bracket. Ensure the screws are tight and the sensor sits flush with the BLTouch sensor bracket (if you have the kit, use the provided M3*8 screws).
Using an Allen key, remove the two screws that hold the hot end shroud.
Align the bracket to the hot end shroud and screw the bracket and shroud into the carriage using the longer screws provided in the kit (the M3*6 screws).
Use the Provided zip ties or cable ties to fasten the cable to the Bowden tube and the hot-end wiring. Tying your wiring to the existing wires ensures the sensor wires don’t get snagged when printing.
Use the Allen key to reattach the print head shroud over the BLTouch bracket mount.
Remove the screws that hold the cover onto the printer’s mainboard. You’ll need to move the print bed forward to access the screw at the back.
Once you remove the screws, slowly remove the cover.
Disconnect the fan from the mainboard, noting its position so you can reconnect it later.
Locate the Z-axis endstop cable and disconnect it. You can set the endstop cable aside. You won’t need to replace the Z endstop cable, as the BLTouch wires will replace it.
Unplug the LCD ribbon cable to make room for connecting the BLTouch wiring.
Connect the 2×3 pin ISP connector to the other end of the included USB ribbon cable. The ISP connector allows external devices like laptops to connect with your 3D printer.
Plug the ISP connector into the 2×3 ISP port on the Ender 3 mainboard. The connector is located beside the LCD connector. Note: Make sure you connect the side that reads “VCC” with the opposite side facing away (“GND”).
While you have the back cover off, it is an excellent time to ensure that all other connectors and screws are secured appropriately. Gently tug on each connector and cable and ensure they don’t get pulled out from their position. If they’re not connected, simply reinsert them, tighten the screws, or push the locking pins to secure them to the mainboard.
Plug the USB side of the ribbon cable into your computer or laptop. After connecting to your computer, a blue light will appear on the mainboard, letting you know it’s connected.
Updating the Printer Firmware
With your Creality Ender 3 connected to your computer, it’s time to update the firmware.
We’ll need to install a BLTouch-compatible firmware file to use our auto bed leveling system:
Visit Creality’s download page for the latest Firmware with BL Touch support. Make sure you select your printer’s latest version of the firmware file.
Select the firmware that matches your motherboard type. The version number is located on the motherboard itself. Look for 4.2.2 or 4.2.7.
Download and extract the BLTouch-compatible firmware file to your computer. Tip: Ensure you download the correct firmware versions for your 3D printer.
Follow the next steps in the progisp software menu to install the new firmware to your printer.
All that is left to do is reconnect the mainboard cover and calibrate your BLTouch.
After cleaning and leveling the bed, follow the steps to calibrate your BLTouch:
Auto home your Ender 3.
After auto-homing the 3D printer, move the Z-axis to position 0.0.
Place a sheet of paper on the build plate under the nozzle and then manually move the Z height (Prepare>Move Axis>Move Z) until you can feel a slight resistance on the paper but can still move it. Note: You might get a negative value, which is perfectly fine.
Write down the ending value. This number is your new Z offset. In our case, the Z-position was -1.25, but yours may be different.
Set the Z offset to the value you found in step 4.
Toggle back to the Control menu and select “Store settings” to save the new Z offset.
Turn off the printer and wait 10 seconds before turning it back on.
Auto home the printer again. Use the same piece of paper to ensure that the offset is correct and that the paper can move with slight resistance.
If the z offset isn’t correct, repeat steps 2-8.
Finally, replace the Gcode command “G28” in your slicers starting script with “G28 G29.” The new code tells your printer to run a mesh bed leveling before every print. (If you’re using Cura, navigate to Preferences > Printers > “Name of your Ender 3 Printer” and click Machine Settings. Under the start code, add “G29 ” below the line “G28”)
You’ve successfully calibrated the z offset to your printer.
Now you’re ready to print. We recommend first printing a test print to ensure there aren’t any significant issues with your changes to the Ender 3.
If you’re having issues after installing your BLTouch kit, don’t panic. Several common problems are easy to fix. We’ve outlined several below:
First layer too low or too high: If your first layer isn’t sticking to the bed, it’s most likely printing too low or too high. Either way, you must adjust your Z offset for a perfect first layer. Visit the above section, “Calibrating your BLTouch and Ender 3 Z-Offset,” and follow the steps to recalibrate the Z offset.
Inconsistent leveling: If you notice inconsistent leveling after installing a BLTouch, it may be caused by a misaligned BLTouch sensor. Your mount may be the culprit if you went the DIY route and printed the BLTouch mount. You can fix it by purchasing a compatible BLTouch mount or reprinting the mount after manually leveling the print bed.
Sensor not probing: You may have switched the wires if the BLTouch probe doesn’t extend and contract. You can fix the issue by flipping the connection of the wires plugged into the Z-axis endstop. Double-check your wiring in the wiring diagram above.
Using a V1 silent mainboard: If your printer uses an upgraded V1 silent mainboard, you must download a different firmware version. Re-visit the “Updating the Printers Firmware” section and download the correct firmware version with “silent mainboard” in the name.
If you’re still struggling, message us; we’d happily help.
Marcello De Lio
Marcello co-founded 3D Print Mentor to share his love of 3D printing. Marcello used to own an online 3D printing company, where he sold unique designs and customized novelty gifts. After closing the business, Marcello’s new passion is 3D printing replica movie props and cosplay items.