How to install the BL Touch on a Creality Ender 3

| Tags:
How to install the BL Touch on a Creality Ender 3

Installation Guide: BLTouch on a Creality Ender 3
Have a Creality Ender 3 printer that you need to auto-level? You’ve come to the right place. We’re going to walk you through how to install a BLTouch mount to ramp up your printing precision. It might get tricky but bear with us. We’ll help you get it done.

If you’re more of a visual person, you can consult our installation guide video here:

What’s a Creality Ender 3?

The Creality Ender 3 is a low cost, compact, pre-assembled 3D printer that has become incredibly popular among engineers and hobbyists alike. It features admirable print volume and print quality for its price. It is also highly customizable with a variety of upgrades available… including the BLTouch.

What’s a BL Touch?

A BLTouch is an automatic levelling sensor that measures the height and tilt of a 3D printing surface to ensure a more precise print job. It works on a variety of surfaces, including glass, wood and metal.

Why would I install a BLTouch on my Creality Ender 3?
The Creality Ender 3 has faced a steady stream of criticism due to its slight wobble from an uneven base. This makes it especially tricky to level, which can compromise the quality of your printing. The BLTouch re-levels the bed surface of your printer to ensure a precise print job every time.

How do I install a BLTouch on my Creality Ender 3?

You’re going to need some tools, but luckily you likely have many of these already on hand. Here’s what you need to be prepared prior to begin your installation:
- BLTouch in a 3D printed BLTouch mount
- Wire strippers
- Soldering iron, solder, and a small piece of heat shrink tube
- 2mm & 3mm Allen keys
- Wire clippers
- 2 pieces of tape/labels
- 1000mm BLTouch wire extension kit
- BLTouch Genuine kit items
- Zip ties
- Star head and slot head screwdrivers
- Arduino Uno
- 5 female-to-female DuPont connectors
- 1 female-to-male DuPont connector

The Genuine BLTouch kit has a lot of connectors- for this build, you’ll only need 2 nuts & 2 bolts to hold it on, so feel free to ignore the rest of the connectors (but be sure to keep them around for future use!).

Phase 1: Preparing the BLTouch for Installation

Take the female-to-male DuPont connector wire and insert it through the wire guide in the BLTouch mounting bracket. You want the connector inside of the bracket, ensuring that the holes of the BLTouch line up with the holes on top of the bracket.

Once you’re happy with the orientation, you can use 2 screws to insert the BLTouch into the mount. The screws are to be inserted bottom-up, where the head of the screw faces the floor. Here’s a pro-tip: do the back bracket first because this is the hardest one to do!

Then, put a spring on top of the bolt, where the largest part of the spring is facing the top. You’ll want to put some pressure on the top as you thread it through the spring, as the spring will attempt to push out the bolt- use a star head screwdriver to hold it down. The goal is to have the top of the bolt come out of the hole so that you can use a securing nut on this end to maintain its position. Once it’s secure, give 5-7 turns of the screwdriver for good measure.

Now, you can easily put the front nut on by repeating the process as outlined above. Be sure to check that each of your springs is holding a similar amount of tension- otherwise the BLTouch will lean one way or another.

Phase 2: Preparing the Creality Ender 3 for Installation

The BLTouch wires are going to go through the extruder assembly. You’ll want to use a pair of wire clippers to cut off any existing zip ties in this area. Once these are removed, use a 2mm Allen key to remove the 2 screws securing the front cover of the extruder assembly.

Next, use the screws you just removed to attach the bracket to the mainframe. It’s easiest to pre-thread the screws in the bracket until you can see them pop out of the other side. Then, you can screw the bracket to the front by lining up the holes with the original placement of the extruder cover. Another pro-tip: start with the top screw- it’s the most exposed and the easiest to thread in. Don’t be afraid to jiggle it around a little bit.

Once you’ve completed this phase make sure that the extruder bracket and mount are secure. Use the Allen key to make adjustments if necessary.

Phase 3: Wiring and Programming

Remove the 2 screws on the front cover of the printer and the 2 screws that hold the whole assembly to the frame. Slide the Y-axis all the way forward and remove the motherboard's back cover screw. Slide the Y-axis all the way back, then remove the motherboard cover. Disconnect the fans by pulling out the red wire. Set the assembly aside.

Lay the printer on its back- be careful, as you don’t want to crush any wiring. Remove the final screw in the motherboard, support it entirely in one hand, disconnect the z pin, and lay it down gently.

Use your clippers to remove the zip tie that holds the cable assembly together. Now, be extremely careful as you separate the sleeve tape from the cables. Try making a small incision and carefully rip it off.

You can then begin fishing the extension cables through the sleeve to connect the BLTouch to the motherboard. Bunch the sleeve up to move it away from the control box components. Insert the male ends of the wires into the sleeve. You’ll likely have to fiddle around- expand and contract the sleeve as necessary to work them through!

Next, pop out the LCD connector and set it aside. Locate the 6 pins beside the LCD connector. This next part can get confusing, as different DuPont cable packs have different colours. It may be helpful to write down on a piece of paper what colour corresponds to what pin. Note that pin 3 is special because this is the pin where the female to male connector connects. If you have trouble with this step, consult this video around 8:38 for a visual explanation. Double-check each pin is going where it is intended to by following the leads on the Arduino side.

Once you’re confident in your wiring, plug the Arduino Uno into the USB port of your computer. It should light up and power the motherboard of the printer. Press “Bootloader” and the lights will put on a little show. If successful, you can unplug the Arduino and the cables.

Now you are ready to unplug the Zeidman cable. There might be some hot glue holding the connectors in- use a screwdriver to carefully remove this glue.

You now need to organize the extension cable pins. Use a screwdriver to carefully pry up the plastic securing the red and orange pins on the extension cables. Once they’re out, re-insert the red pin so that it is in the outermost slot with a 1 pin space between the red and brown.

Next, splice the remaining orange wire into the red wire of the LCD ribbon cable- this is important, as this is where the BLTouch gets its signals from. To access the red cable, peel it away from the LCD ribbon cable assembly. Then, use clippers to cut it 2.5-3 inches from the connector side and cut short the side leading to the LCD (we only need the connector side).

Once your red wire is ready, clip the orange cable at the connector. Both the red and orange wire ends should now be free. Use your wire strippers to strip off a length of wire, and then braid them together.

Now for the fun stuff! Take a 1-inch piece of heat shrink tubing and fish it onto the end of the orange connector. Then, use a “Western Union” joint (cross the wires opposing each other and wrap them around like a handshake to grip each other) and apply some solder to it. Use the iron to heat the solder, then let it cool slightly before placing the heat shrink tube over the joint. Use a little more heat to shrink the tubing so it’s secure.

You’re now ready for more wiring. Insert the red and brown wires into the motherboard. An Allen key might be useful to line up and push in the connector. Use the black and white Z end stop connector so that the black lead is going to the first pin of the Z end stop and facing the inside of the board. The white lead should face the outside of the board. Again, use the Allen key to push in the pins and ensure they are secure.

Next, re-plug the LCD screen connector into its housing.

Phase 4: BLTouch Integration

Take the BLTouch and extension cable and connect the colours- white to white, black to black, and orange, red, and brown each go to their respective colours. It is pretty easy for the connectors to become disconnected in the middle of a print, so you’ll want to use a label or tape over the joint, so the connector is more secure.

You’re nearly done now! It’s time to test that your wiring has been connected properly. Put your motherboard back in its area without screwing it in, and carefully rotate the printer upright.

Turn the printer on. If all is well, the plunger will go up and down twice and then glow red. This means you can continue with re-assembling the printer. If you don’t get this response, you need to double back and check your wiring.

Phase 5: Re-Assembly

Screw in the motherboard housing and tuck the wires in. Use a zip tie to hold the wiring harness together. Leave a little bit of slack in the wires before using wire pliers to pull the tie tight. Re-attach the fan using the red wire and re-install the lid. Don’t forget the screw on the motherboard’s bottom!

If you’re a zip-tie fanatic like me, you may want to use a second zip tie on the outside to make sure the wiring harness is secure. At the risk of sounding like a safety squirrel, I suggest a third. Why not- zip ties are cheap!

Finally, you need to replace the zip ties we removed earlier on the extruder and cable assemblies.

Phase 6: Ditch the Z Minimum End Stop

You have a BLTouch now, so the Z minimum end stop isn’t of much use and will only get in the way. Loosen its screws and take that sucker off completely.

Plug your USB cable into the front of the printer. With a boot loader, you can flash it via USB- use this to guide you!

Phase 7: Configuration

Auto home the printer so that the X and Y home each other before moving to the center to home the Z. It should probe the bed twice.

If all is well, you can set your Z offset using a default value of -3.50mm. Be sure to click Store Settings!

Next, navigate back to the Main screen. Auto home the printer again, before selecting Motion. Then, select Move Axis and move Z by an increment of 0.1mm. This will allow you to determine your Z offset.

To test this, put a piece of paper between the bed and the nozzle and slowly move the head down until it begins to grip the paper, without stopping the movement of the paper. Now, check the LCD to see how much is left.

Go back to the Configuration menu to set the probe offset. To do this, find your probe offset, and add whatever offset remains to your Z probe. For example, if the probe offset is -3.5 and you had +0.5 left, add the latter to the Z probe. This would make -3 the total Z probe offset. Be sure to click Store Settings to save this!

Now, you’re going to configure Kirra on your computer. Go to Settings, select your printer, select Manage Printers, select Machine Settings, and note your Start G code. You will need to enter a new line for your BLTouch homing. Once you’ve completed this, click close, then close again.

Your new code will make a grid by measuring 9 points throughout the bed surface, as opposed to just probing the bed twice. And that’s it, you’re done!

If you’ve made it this far, congratulations. This installation process can be tricky, but you did it. You can now enjoy all the benefits of an auto-leveling 3D printer!