Enclosing the Ender 3 V2 Part 3: Wiring

Earlier this week, I posted about removing the motherboard, display, and power supply from my Ender 3 V2. This was done to prevent heat damage to the electronic components when printing high temp filaments. Now it is time to hook those electronics back up. This post will show the steps I made to accomplish this goal.

Due to a problem with a MicroSD card, there are not as many pictures with this post as there usually would be. The pictured included were all taken after the process while a print is going. So they may not always provide the best reference.

X and E wiring

X-axis motor, x-axis limit switch, extruder motor, and hotend wiring is the easiest to move outside the enclosure.

The cabling for the x-axis motor, x-axis limit switch, extruder motor, and hotend wiring is the easiest to move. These wires are along long enough to go outside the enclosure without being replaced or extended.

The wiring bundle going to the hotend has the cabling for the following:

  • Parts cooling fan.
  • Hotend cooling fan.
  • Hotend thermistor.
  • Hotend heater cartridge.

These can all be hooked up to the motherboard as follows.

  • The parts cooling fan is the yellow/blue cable and goes into the port labeled K-FAN1. As pictured, it is the bottom of two ports just slightly below the other connectors.
  • The hotend thermistor connects to the first port (from the left as pictured). It has two white wires.
  • The hotend heater cartridge wires go into the two first terminal block ports (from the left as pictured).
  • The hotend fan goes into terminal block 5 for the black wire and terminal block 6 for the red wire (as pictured).
Hotend connections into the motherboard.

The extruder motor, x-axis motor, and x-axis limit switch all join together in one ribbon cable that feeds back through the same sleeve as the above-mentioned hotend wiring. These hook up to the motherboard as follows:

  • The Extruder motor cable hooks to the leftmost port on the bottom.
  • The x-axis motor cable goes to the right-most port on the bottom.
  • The x-axis limit switch hooks the right-most 2-pin connector along the top of the motherboard. It is labeled X.
Extruder motor, x-axis motor, and x-axis limit switch connections to the motherboard.

Y-axis wiring

Y-axis motor and limit switch.

The y-axis wiring is a little more tricky. These cables will not reach outside the enclosure, at least not for my setup. The only cabling here is the wiring for the y-motor and for the y-limit switch.

For the x-axis motor, I decided to extend the current cable. I cut the cable in the middle. Then I soldered and shrank tubed a section of 22 AWG wire between the ends. I made sure to give enough room to easily attach that cabling to the enclosure frame in the future.

The limit switch was a little more tricky. It took me a while to figure out how to remove the limit switch housing. After taking out the screw, you can take the housing off by pushing in on the housing’s top and bottom. This will allow the housing and the limit switch to be removed. For the limit switch, I made a new cable using 2-pin JST-XH connectors and 22 AWG wiring. If I had realized it would be such a pain to remove the limit switch housing, I might have just extended this cable like I had the y-motor cable.

The wiring connects to the motherboard as follows:

  • The y-axis motor connects to the third port on the bottom. It is labeled Y.
  • The y-axis limit switch connects to the fourth port on the top. It is labeled Y. You can see here my custom cable was made using blue wiring.
Motherboard connections for the y-axis motor and y-axis limit switch.

Z-axis wiring

The z-axis wiring is pretty much the same as the y-axis. These wires were also too short of reaching outside the enclosure as I planned. I used the limit switch cable I had taken from the y-axis limit switch and connected it to the switch’s z-axis limit switch. It was more than long enough for this purpose.

If I had thought ahead of time, I could have used the y-axis stepper motor cable as a z-motor cable without modification. But I had already extended the z-motor cable. Maybe I’ll think of that next time I do this on a printer.

This time, I decided to put a new JST-XH connector on the stepper motor cable’s motherboard side. So I cut the z-axis motor cable and soldered four AWG 22 wires to it. I then crimped a four-pin JST-XH connector on the end. It is critical to watch the pinouts on this. The two center pins are swapped on the cable.

Here is how the z-axis cables connect to the motherboard.

  • The z-axis motor cable goes to the second port on the bottom. It is labeled as Z.
  • The z-axis limit switch cable goes to the third port on the top. It is labeled as Z.
Motherboard connections for the z-axis stepper motor and z-axis limit switch.

Heated bed

The heated bed was the last thing to be run from inside the enclosure to the motherboard. These wires were not even close to being able to make it the whole way. The cables here go to the heated bed thermistor and the heated bed heater cartridge.

I decided to extend both cables. I used 22 AWG wire to extend the thermistor and put a two-ping JST-XH connector on the end. I then soldered and shrank tubed that to the current thermistor wire.

XT-60 connector.

To extend the heater cartridge cables, I chose XT-60 connectors. I know some people may balk at this because the Ender 3 Pro had problems with a crimped version of this connector being a fire hazard in the past. But I’ve used XT-60 connectors for many things and have never had issues with them if they are correctly soldered. Ironically, Creality chose to drop the XT-60 from the Ender 3 design; and I decided to add it back on.

The two heated bed cables connect to the motherboard as follows:

  • The heated bed thermistor cable goes to the second two-pin connector at the top of the motherboard. It is labeled TB on the motherboard.
  • The black wire from the heated bed heater cartridge went into the third terminal block position, and the red wire went into the fourth terminal block position.
Heated bed connections to the motherboard.

Time to power up!

The final step is to add power back to the motherboard. This would only be temporary. My long-term plan is to have all three power supply outputs being used. One output will go to the 3D printer, as it is now. A second output will go to a buck converter, which in turn will power the LEDs. The third output will go to another buck converter, which will, in turn, power the Raspberry Pi. There will be a rocker switch between the power supply and each of these components. That will allow me to power the 3d printer down without worrying about impacting the Pi.

But those are future plans. For now, I hooked the power supply back to how it was initially hooked up. The wires connect into the two-port terminal block on the right side of the motherboard. The ports are labeled + and -.

This was also when I hooked up the following:

  • Ribbon cable going to the display (the display is going to mount on my wall eventually).
  • USB cable going to the Raspberry Pi.
  • Inserted the MicroSD card.

Here is how the current setup looks. The motherboard is in an early prototype test for a case I’m designing. This looks like a bit of a mess now. But I will clean all the cabling up when I get the new case printed for it. The power supply is also sitting on top of some 3D printed blocks/feet to ensure adequate airflow.

3D printer electronics all moved out of the enclosure and powered up.

I initially tested the motors by sending a series of commands from Octoprint. Everything was working as expected. Each motor was going in the proper direction, and the limit switches stopped the bed at the appropriate time. Both heated cartridges and thermistors appeared to work correctly. After leveling the bed, I started it on a print job. As you can see in the video below, it is printing just fine.

Test print.

Comedy of Errors

Technically running the cables outside of the enclosure was a reasonably painless process. By taking the time and paying attention to detail, there isn’t’ anything hard about the process. But apparently, the tech gods decided to mess with me on this part of the project.

Below I’ve included some of the things that happened during the steps outlined in this post. None of these were relevant to the post, but I thought someone would like to see what happened to me; so they don’t feel alone, thinking sometimes projects have things go wrong.

  • My flush cutters broke in half while cutting stranded 22 AWG wire.
  • My good crimper had its mechanism break, which forced me to use a substandard backup crimper.
  • The power supply got knocked off the table and landed on my toe. Don’t worry, the power supply was not plugged in and is OK.
  • I could not find my JST-XH pins for anything. They weren’t where they were supposed to be. I eventually found them hanging out in the container with Dupont pins. Apparently, they were having a date night.
  • Twice my soldering iron tripped the circuit breaker. I had to go out to the garage in sub-freezing weather with a flashlight to find a new breaker. With the new breaker in, I’ve had no further issues.
  • My phone completely disappeared. I eventually found it in the cold and dark garage…
  • And last but not least. The camera I used to take pictures of the process had a problem with the MicroSD card. I’m not too fond of MicroSD cards.

But having gone through all that, I still was able to get this project done. Working on projects like this is an excellent way for me to stay relaxed! Things going wrong or unexpected is, well, expected. 

Next up: The case

The next post in this series should be about the 3D printed case. I’ve had some problems with Fusion360, so that process has slowed down a bit. But I have a temporary case designed and currently printing. Long-term, I’m going to start over and try a different design. This is more about learning the process of creating cases than worrying about finding a suitable case on the web.

Song of the Day: The Naked Truth

Seeing the motherboard all naked brings this great Golden Earring song to mind.

Bonus Song: Twilight Zone

I’ve apparently been in a bit of a Golden Earring kick lately. But then sometimes doing projects like this can feel like the twilight zone when weird things keep happening.


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