Guide: Build Your Own USB Cables for Mechanical Keyboards

by Joshua Cruz May 14, 2022

Hello Everyone!

Thanks for taking the look at the first DIY tutorial picture guide on this site.

Cables are something that we often over look everyday, but they are what allow us to use our favorite devices. Being able to make your own cables is a great skill. There are countless times, I've needed a cable for various devices from a printer to even audio devices and having the knowledge to make my own cables has been a very rewarding hobby. In my opinion, this is also an excellent way to learn how to solder as it is relatively inexpensive to make multiple continues to continue on honing your skills.

In this guide, I'll be showing you how you could build your own custom double sleeved cable intended for use with mechanical keyboards.

If you prefer to see this guide as a video, take a look at this DIY Cable Tutorial Video

1) Prepare your parts / tools
The first important step is to make sure you have everything you need to put together the cable.

For the cable parts, I'm using a DIY Cable Kit w/ the following specs:
4ft Length
Device Connector: USB-C (Gold)
Host Connector: USB-A (Gold)
Paracord Color: Royal Blue
Techflex Color: Teal Blue
Heatshrink Color: White
And an Oopsie Pack which is basically an extra set of device and host connectors in case any mistakes are made

For the tools, I've compiled of spreadsheet of tools I use here (and recommendations for beginners): Cable Maker Spreadsheet

2) Cut both ends of the paracord and remove the inner strands
Snipping off both ends of the paracord will allow you to remove the inner strands. You should be able to smoothly remove the inner strands.

Take your time doing this and make sure that the paracord does not snag as you remove it as it may damage this layer of sleeving.

3) Sleeve the cable with paracord
Incrementally guide the cable into the paracord. Smoothly sleeve your cable and remove slack from the sleeving as you complete this process.

4) Trim the paracord
I typically aim to have the paracord sleeve the cable with about 1 inch of extra cable length on each side to allow us easy access to solder our connectors.

It's better to have more exposed cable than less as you can always trim it along the way.

5) Melt one end of the paracord onto the cable
Carefully melt one end the paracord onto the cable with a lighter.

This is an important step to prevent the paracord from moving as I continue to work on this cable.

6) Sleeve the cable with Techflex and trim the excess
This layer of sleeving should be fairly easy to add on. Make sure to start sleeving on the same side of the cable that you melted the paracord on.

I typically trim the Techflex to the end of the entire cable after sleeving.

7) Pull back some of the Techflex to expose the cable
We will need some space for us to access the cable itself for soldering. At the same time we do want to make sure we have enough Techflex to sleeve the entire cable.

It's better to keep excess Techflex on the cable as you can always trim it later.

8) See how much unstripped cable you need then strip the cable jacket
First we need to find out how much unstripped cable we will need to secure the connector onto the cable. I use the USB-A shell to see where it lines up on the cable. After doing so, I will strip the black jacket off of the cable by gently using the wire cutter part of my wire stripper.

9) Remove the metal shielding from the cable
At this point I will reveal the wires by removing the metal cable shielding. The metal shielding should be easily moved with your fingers.

To to cut shielding off I use a pair of micro cutters.

10) Lineup your wires to the connector and trim as needed
Here I take a look at the lengths of the wires as I have them in position. I typically like my wires to go up halfway up the metal pads of the USB-A connector.

If you think you might need to trim some of the wire, do make sure that you want to minimize the amount of exposed wire once the soldering is completed. As with most steps in making this cable, it's typically better to have a little more than you need as you can always trim it later.

11) Strip the individual wires
You should have a good idea of where to strip your wires after seeing how they lined up in step 10. I will use the 28 gauge section on my wire stripper to strip each wire.

12) Add solder to your exposed wires and connector pads
This process will allow us to easily soldering this all together (also known as tinning). I personally use my soldering iron at 590F, but your mileage my vary depending on the soldering iron you are using.

Make sure to add an good amount of solder as we move onto the next step. I am using a pair of helping hands (listed in the tools spreadsheet listed at the beginning of this guide) to help me with solder work.

13) Solder your wires onto the connector
The pinout I am using can be found in the pdf section here: DIY Resources
(a pinout is basically the order in which the wires are soldered)

My way of doing this is to heat the solder on the pads to until it is liquid then guide the wires onto the pads using a pair of tweezers.

Make sure there is no bridge of solder connecting each of the pads as your cable will not work. Also minimize the amount of exposed wire as best as possible.

14) Attach the USB-A metal shell
Attach the metal shell by first sliding over the larger part of the connector. I typically like some adhesive over the wires to add some extra durability to the cable. The smaller part of the USB-A shell should snap into place afterwards.

15) Secure the USB-A metal shell
With a pair of pliers I secure this connector onto the cable. I try my best to make sure to secure this as best as possible to reduce the amount of wiggle for the connector.

16) Prepare the other side of the cable for the device connector
We'll basically be repeating steps 6-15 on the other side of the cable for our USB-C connector.

At this time I also remove any slack from the sleeving by running my hand across the cable to prevent any lumping in the sleeving as we're getting closer to finishing this cable.

17) Tin and solder the device connection
Typically the devices connector surfaces are much smaller. This is great practice to become more precise with the soldering work.

Again, you can find the pinout I'm using in the pdf section here: DIY Resources

And remember to make sure there is no bridge of solder connecting each of the pads as your cable will not work.

18) Secure the device connector shell
One thing that I like to keep in mind differently regarding this side of the cable is that I like to start with the teeth side of the shell first. There should be a little notch in the shell that the connector should fit snug into place. I would recommend to use an ample amount of adhesive to this part of the cable as it is the most likely to seen the most movement during regular use.

The second part of the shell should snap into place. You can then secure it with a pair of pliers.

19) Add the heatshrink to the device connector
My preference is to apply the heatshrink at the end of the USB-C shell. After that I'll take my heatgun and have it shrink around my cable.

Keep in mind that Techflex does have a melting point of around 500°F. You can easily melt your Techflex sleeving if you aren't careful.

20) Add the heatshrink to the host connector
For USB-A connectors, my preference is to apply the heatshrink just a little bit under the notch on the USB-A connector. After that I'll take my heatgun again and have it shrink around my cable.

21) Test and enjoy your new cable!
If you did everything correctly, you should be able to plug your cable in and celebrate your success.

Here are a few other additional tips I can offer to help you in your cable making journey.

- With a sleeved cable, you can solder both ends first and test the cable before adding the housings.
- If you have access to very thin heatshrink, it can be used as an extra layer of protection for your solder points.
- You don't really need the sleeving at all especially if all you need is a functional cable. It also might be a good idea to start very simple by making an unsleeved cable if it's your first time.

Hope this guide was helpful for you. Thank you for taking the time for checking out this guide, and I wish you the best with your cable making journey.

Make sure to signup for the newsletter at the bottom of the site as we're planning to e-mail more tips and tricks on a monthly basis moving forward.

Thanks again and make wise choices,
Josh