Installing BLTouch Auto Bed Leveling Sensor on Your Creality Ender 3 Printer

Omri Ben-Bassat
Jun 19, 2019 · 3 min read

After getting tired lately from calibrating my Ender 3 printer again and again I finally decided it’s time to fit it with some auto bed leveling capability. So I did small market research and learned that there’s a bunch of available sensors of this kind from few different manufacturers, the main once are EZABL and BLTouch. Both seem great but I decided to go with BLTouch because it’s little cheaper and also there’s a full conversion kit for my Ender 3 from Aliexpress for ~40$ available, which makes it little easier to install.

The kit I got was exactly like the one in the product description/pictures, including all the parts you need and pretty clear instructions which could be improved a little, but in general, it’s a good quality kit. The kit includes the sensor itself, sensor bracket, ISP(In-System Programmer) to upgrade the printer’s firmware, screen adapter, cables, screws and zip ties as you can see in the following picture:

Installing the BLTouch sensor

The goal of this post is not to replace the instructions provided by the manufacturer but rather give you, the reader, a general idea of the process of installing this sensor, that said, let's start!

  1. The first step for me was to mount the sensor under the fan cover, I used the supplied bracket and replacement screws which are a bit longer, everything fit great.
In the picture, you can see where the fan cover screws go.

2. Now we need to upgrade the firmware before connecting the electronic, I opened the mainboard cover and plugged the supplied ISP. You can find the official Creality firmware for Ender 3 with BLTouch in here once downloaded you get an archive with the firmware itself, progisp.exe(1.72) which is the application you are going to use in order to burn the firmware and full instructions, follow them!

3. Ok, now that we got the sensor attached and new firmware it’s time to hook up the electronics. We need to do two things — one is to disconnect the Z-axis switch and replace it with the cable from our sensor, and the second is to disconnect the screen cable, and reconnect throw the supplied adapted which also connects to the sensor.

At this point, you’ll probably notice that you can't put back the cover! The screen adapter makes the cable too high and it’s hitting the fan! Turns out it’s a well-known issue with this kit, Some people suggest to try and bend the pins, but since I was afraid of breaking stuff I decided to print this alternative cover which moves the fan. After ~2–3 hours of printing, I could reassemble the original fan and now everything fitted perfect, maybe I’ll paint it black sometime in the future…

Alternative cover from Thingiverse, by Hometinker12.

That’s it! Now we're only left with doing some one-time calibration(follow the instructions) for the Z-axis offset and that’s it! No more manual bed calibration!

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