How annoying is having a USBC cable hanging out the front of your Ender 3 S1, not only ugly, but also a good cause of failed prints :/

Lets do something about it :)

Supplies

You will need some basic soldering skills...

Soldering Iron
Solder
IPA ( Isopropyl Alcohol ) for Cleaning ( Cotton Buds / Q-Tips )
Ideally a Dupont crimping tool and female crimps ( not sure of the appropriate PC name !)
2.54mm PCB Pin Headers
Heatshrink tube
Allen key / Hex Wrench kit that came with the printer.

Step 1: Remove the Base

To get access to the motherboard you will need to find yourself a nice clean workarea, and remove from the printer the filament reel, and disconnect all external connections, USBC, Power.

Lay the printer on it's side, but please take care when doing this, as you need to make sure the bed or print head don't flop around too much, it's probably worth getting some help to do this.

Now you hopefully have full access to the base of the printer, around the base are a number of hex key screws (8), remove these and the base will drop away, you will need to remove the fan connections, I recommend taking photo's to ensure you get the plugs back in the correct positions, you can do this without disconnecting the fan, just have to be careful so not to stress the cables and connections. Unfortunately I do not have these as I have modified my printer and removed the stock items so cannot provide photo's for reference.

Step 2: Mainboard Modification

Now is time to gain access to the MainBoard so the PCB headers can be installed/soldered in place..

The image above shows the location of the screws, I did this without removing the cables, I'd suggest you doing the same if you can, if not, take notes/pictures and ensure when reinstalling to add some hotglue to prevent them coming loose down the line.

Snip off a group 4 from the PCB header strip, places them in and solder.

Use some IPA and Q-Tip's to clean away the flux residue.

Now replace the mainboard.

Thats the main part of the modification done.

Step 3: USB Cable Preparation

For my purposes I used a MicroUSB cable, it is the same for a Standard USB cable as the pinout is the same...

Time to break out the Dupont Crimping Tool, female crimps and a 4way connector.

If I were to go into how to carry out this I would be reinventing the wheel, I'd suggest watching a few YouTube Videos on crimping DuPont Cables. I can recommend BigClive for this : https://www.youtube.com/watch?v=DXLmuDbcLBM&ab_channel=bigclivedotcom

Please note, do not use the Positive ( usually red ), it is not needed and can cause issues down the line.

All that is required are GND, Data+ ( Usually Green) and Data- ( Usually White).. I'd strongly recommend using a Multimeter to verify the colors and pinout as it is not unknown for some suppliers not to follow standards.

Use some heatshrink to keep things nice and tidy if possible, if you have none, some care with electrical tape and am sure a good job can be done.

Step 4: Plug It in and Finish

All that is left now it to plug in your cable, route it out through the base plate ( may need to make a hole ), everyone has their own preferences so I am not going to tell you the best way, I will leave that to yourself to decide.

I would suggest that you use strain relief to prevent accidental disconnection and if routing through a hole ensure you use a rubber grommet to prevent chaffing.

Replace the base, stand the printer back up, plug your USB into your Pi or whatever you are using, power up the printer, and you should see the USB connection as normal in whatever application you are using ( Octoprint my in my case).

Note.

All is not lost if for some reason you managed to pull the socket out, just pop the front cover off ( 4 Allen screws ) and access is easy ( I know, I did it ).