Introduction: Retrofitting USB-C to a 3D Printer

About: Mechanical Design Engineer in the Automotive Industry

It's always worth keeping up with the times with minimum investment. I've first bought my 3D printer three years ago and unfortunately after a long wait , the printer was shipped with a broken SD port. All I was left to do was either return it and wait another few months for a replacement or find connectivity alternatives.

This is where all the "fun" starts. Ever since, I've been running the printer around the clock using OctoPi which is very popular among the makers community.The OctoPi uses an USB to USB Mini cable to connect to the printer. I've tried different setups like straight connectors or right angled ones but they all kept on failing. This resulted in a lot of hassle every time I needed to print something. Had to wiggle the cable around to find the right spot (no pun intended). Tried different brands as well, nothing lasted long and when you use the printer over a thousand of hours it can become a little bit frustrating.

My first experience with USB-C cables/connectors was when I upgraded my phone. This time I took a leap of faith and changed from iPhone to an Android Phone.I started to kinda like how the connector clicks in and works. I personally thought it was a very good design.It didn't last long until I started to buy my electronics with USB-C only connectivity. This meant I was fully loaded with cables , different colors/brands/lengths.

I then realized that it shouldn't be that difficult to change the connector on other hardware as well so I ran my first trials on some inexpensive Chinese knock-offs for Arduino Nano. As the process was a success I decided to try my luck and convert my 3D printer as well.

Step 1: Materials and Tools

Beauty of this project is that it can be done with basic tools which most electronic enthusiasts have lying around.

The minimum tools you will be needing are :

  • Solder iron - it can be a very basic one or it can be a soldering station,anything goes
  • Solder- I personally use 60Sn/40Pb 0.4mm/0.8mm dia
  • Tweezers - makes the fitment of the copper wire easier
  • Pliers
  • Helping hands - I used a 3D printed vice (please refer to the Youtube Video)
  • Hand drill
  • 3MM drill bit
  • Hex screw driver 1.5MM and 3MM
  • Needle files
  • Multimeter (only optional for troubleshooting)

Now that we've spoken about the tools here is a list with the materials:

  • 3D Printer filament - aprox 0.53m for the adapter I designed
  • USB-C Breakout - any brand works , the one I used is from POLOULU
  • Enameled copper wire 29AWG - you can use different diameters and coatings but I found my combo to work the best
  • 2 x M3 x 15MM hex screws
  • 2 x M1.5x5MM hex screws

Step 2: Removing the Main Board From the 3D Printer

As different brands have different layouts and case designs I can only offer here a few tips and tricks on how to make this process fool proof.

  • Be very gentle when working with electronics.Sometimes the connectors won't come apart very easily. My printer for instance is an CREALITY ENDER 3 and all connectors on the main board were covered with hot glue. Please take your time and use minimum force when you work with the main board;
  • If you've never done this before it's a good idea to mark all cables and connectors to their correct location.This will come handy when re-assembling everything. You can find schematics for most consumer 3D Printers on the market so if you fail this step there is still hope. You can trace all cables to see where they lead and all you have to do is match them to the correct connector.

Step 3: Removing the Old USB Mini Connector From the Board

This is a tricky step where with a little patience it should be doable

  • Add as much solder you can on the 4 little legs of the connector shield and also on the 5 connector pads
  • Work your way around the connector trying to keep the solder fluid
  • The bigger the solder blobs you created are the easier it will be to keep them fluid

  • While you keep the solder fluid, try to gentle push the connector away.It is very important you don't pull or force the connector as it might result in broken pads like I did on my first trial board
  • Refer to my YOUTUBE video to see how i did it
  • Once the connector is out if you need to , you can clean all pads using solder wick
  • Large chisel solder tip is recommended for its good thermal inertia

Step 4: Wires Preparation and Soldering to Printer Main Board

During this step we'll have to prepare our wires for soldering

  • cut your wires to the desired size
  • clean the ends from enamel by turning your solder up to 380C deg-if you solder station doesn't support heat control you can gently scrape the enamel off the wire using a sharp craft knife
  • transfer solder on both ends of the wire and proceed with soldering the first end on the printer main board
  • for doing this I recommend a small chisel solder tip

Step 5: Preparing the USB-C Breakout

Now we will have to screw the USB breakout board to the adapter I designed.The adapter will further serve to fix the whole assembly in the desired place on the 3D Printer housing. My recommendation is to find the best spot where its closest to the old connector to keep the wires as short as possible.

For the assembly you will use the 2 x M1.5 x 5MM screws which will thread straight into the adapter

Step 6: Preparing the 3D Printer Housing

  • Place the USB-C connector on the 3D Printer housing in the position where you want to install it
  • Draw the USB connector contour on the contour using a pen
  • During this process also draw the position where the side fixings for the adapter will be
  • Start drilling out the material using the 3MM drill bit
  • You will need to drill exactly 3 holes one next to each other
  • Once you've done that, start filing gently the opening until it matches perfectly with the contour you've drawn
  • If you're satisfied with the job you can proceed with doing a final assembly of the USB-C Breakout/adapter combo

Step 7: Final Solder

Once the breakout is the correct position in the 3D printer housing you can proceed with fixing the main board back to its place. At this stage you only have to use the screws to fix it back up but don't start putting any of the harness back as you need as much space as you can get for the moment.

Proceed with soldering the copper wires onto the breakout board.Be very careful what cable goes where.On this step refer to the scheme I have provided or to the YOUTUBE video.

Step 8: Final Assembly

After soldering the last of the wires you can proceed with installing all harnesses and connectors back to the printer main board.

Take your time and make sure that everything goes into its correct place. I cannot stress enough how important it is to pay attention on the order of the wires. I personally managed to switch a few of the wires and break one of the stepper motors drivers.

Before you proceed with testing the printer I recommend doing a visual check on all solders and wires. If you have a Multimeter handy you can check the resistance of the wires by placing the testers on the PCB pads. This will ensure that all wires are connected and working as they should.

Step 9: Power-up and Testing

After you finish putting everything back together it's time for a test.

  • power up the printer and insert the NEW USB-C cable into the printer
  • power up OctoPi and try connecting to the printer
  • switch to the control tab and tell the printer to move the bed and printer head in different directions

If this process is successful then you can call it a win and start making stuff!

*if OctoPi fails to connect to the printer I would advise another careful visual inspection over the solders/ wires/connectors to make sure everything is in place. If the resistance measurement over the 4 wires matches this means the issue is not coming from the transplant.

Step 10: Final Words and Thoughts

Some people will find this process messy and I do agree it's not the cleanest way to do this but please bare in mind the following:

  • none of the mods are visible as everything is inside the printer case
  • the mod is safe even if the wires touch together as they are covered in enamel which is a very good electricity insulator
  • the wires I have suggested are the perfect balance between reliability/ rigidity/conductivity
  • you wont be able to break the wires but more likely to pull the pads off the PCB before damaging them what so ever

Depending on where you source your parts from, it shouldn't cost you more than $10 for materials only.

When I first started looking at doing this mod to the printer I had a different option on the table. Unfortunately I wasn't able to source the parts out that I needed due to availability.In the end this solution would have worked out quite expensive so I chose to leave it for the moment.

The idea was to use some connectors from JST which would fit straight on top of the old USB Mini PCB pads.

The connectors in discussion are:

In my opinion this would have been the cleanest most presentable way of doing this transplant. The option is still on the table for the future once I manage to source the parts out.

Let me know what your thoughts are and leave a comment down below. If you have the time it's always best to see the actual video I made with the whole process.

If you like it , don't be shy and show some love! This way I know you enjoy my content and it will be fuel for many projects to come in the future!