How Does Customized Computer Connectors and Cables Work?

How to make a Wiring Pinout Diagram

The next Topic that We'll Cover here is How to Use the Stock Cables to make a Wiring Pinout Diagram. This is VERY important to get right if you're making Custom Modular Cables because while the Component end Pinout is Standardized the modular connections on the PSU end are Not. This as you may know is why you should NEVER Mix and Match modular cables from different PSU manufacturers and even the same manufacturer's cables can be Different if they Come From Different Product Line ups. For Example, The Pinout For a SeaSonic Focus GX-850w and Focus PX-850w have Compatible Pinouts BUT the Wires are Rearranged in the plugs. So as a rule of thumb If you are in any doubt at all Use the stock cables as a Reference.

"Great, so how do I make a Pinout diagram?" I hear you ask. Well, the way I go about making Wiring Diagrams is with an Excel Spreadsheet. Link to my 2 Pre-Made templates Here:
https://docs.google.com/spreadsheets/d/1cfkwCasqu0TaBpsh2sOFpGfzZ-jr-vyRqb6oikLrmIo/edit?usp=sharing

https://docs.google.com/spreadsheets/d/1koxHj3m6TkuUoVBm4G4rbdPLIqj5jBBZGiDQre_iemM/edit?usp=sharing

To Easily tell Which wires go where I suggest using a DMM or Digital Multimeter and Probing in Continuity Mode. A Cheap Multimeter will do just fine here so no need to go out and spend $100+ just get one that is reasonably priced if you don't have one already. $20-$40 should suffice here. The process of probing is Simple and I covered it in an Old YouTube Video with a PSU I got Off eBay for $20. Link Here:

Materials

Red = Required
Orange = Optional
Yellow = Depends on Setup

Here are all the Materials you'll Be working with for Custom Modular cables:

16 AWG GPT 60V 85°C Wire or Better​

18 AWG GPT 60V 85°C Wire or Better​

4.2mm Terminal Pins Female​

Molex 4.2mm Connector Male Plug 2x12 (Component End 24 Pin)​

Molex 4.2mm Connector Male Plug 2x5 (PSU End 24 Pin)​

Molex 4.2mm Connector Male Plug 2x7 (PSU End 24 Pin)​

Molex 4.2mm Connector Male Plug 2x9 (PSU End 24 Pin)​

Molex 4.2mm Connector Male Plug 4+4 (Component End EPS)​

Molex 4.2mm Connector Male Plug 2x4 (PSU End EPS 8 Pin)​

Molex 4.2mm Connector Male Plug 6+2 (Component End PCIe)​

Molex 4.2mm Connector Male Plug 2x4 (PSU End PCIe 8 Pin)​

Molex 4.2mm Connector Male Plug 2x3 (PSU End or Component End)​

Molex 4.2mm Connector -R Male Plug 1x5 (PSU End For Some PSU SATA/Molex)​

3.0 mm Small Terminal Pins Female ​

Molex 3.0mm Connector Small Male Plug 2x6 (Nvidia 12 Pin)​

Molex 4 Pin IDE Connector Male Plug (4 Pin Molex)​

Molex IDE Terminal Pins Female​

SATA Terminal Pins ​

Butane ​

Thin Single-walled Heat shrink​

Dual Walled Adhesive lined Heat shrink​

Solder​

Flux​

4mm 7 strand 550lb Paracord​

4mm Expandable Nylon PET ​

Cable Combs​

​

Depending on the Cables you need for your build you'll need to do the math for what you'll need to buy, but as a beginner, I'd recommend getting about 10-15% Extra of certain materials like Wire, Pins, Sleeve, and cable combs. ​

​

Wire Specifications​

​

Let's start with what wire specification is "Best" for a Computer Application. The most important aspect of any wiring project is that safety is our #1 priority. Inside an ATX 2.0 Compliant PC Power Supply Unit there typically are 5 Voltage Rails:​

+3.3V
+5V
+5VSB (5V StandBy)
+12V
-12V

The 3 Main Voltage Rails are:

+3.3V
+5V
+12V

So the highest Voltage that will be running through the Cables you make will Be 12 Volts, ∓ about 5% Maximum in Voltage Ripple depending on the Specific Power Supply's Output filtering. So what all that means is that the Wire you choose needs to be stated as having a Voltage Rating of At least 12.6V on the absolute lowest End. Of course, I always recommend people overbuild their Cables to ensure maximum safety and to ensure you are operating under the Ideal temperature range. Most PSU manufacturers will typically Use 18AWG UL Stranded Wire for their stock cables and while its EXTREME overkill (in a Good Way), If you aren't a Big manufacturer with Millions of dollars to spend on just wire in bulk then it may make more sense to buy 18AWG 60V GPT (General Purpose Thermoplastic) wire with a temperature rating of -40°C to 85°C.

Temperature Ratings and My Testing

The Temperature of your Custom Cables will Probably Never be an issue for Safety if your wire Has a Temperature rating of 85°C or higher. In My testing in a 20°C Ambient Environment ∓0.85°C, a Standardized Testing platform Using a ti FTW3 and Ryzen 7 x, in a Choked-off Hot box Case (d in Negative pressure) running under Full Synthetic Load on GPU and CPU the Worst Internal Case temp I Recorded was 37.9°C ΔT over Ambient, and the Cables (tested at the Component End 12v Pin) was 2.6°C ΔT over Case. That brings us to a Worst case Scenario of an Operating Temp of 40.5°C ΔT over Ambient. If we were to assume an Unrealistically Hot Ambient Temp like 37.8°C (100°F), our Cables are coming in at 78.3°C under a 100% System Load in a Choked-off case with zero Fans set as intake. Definitely pushing it, but still Within the 85°C Maximum safe operating Temperature. Also Important to mention You'd Run into the Computer Thermally shutting down well before Your cables exceed 85°C because of the CPU and or GPU exceeding Tjunction Max.

If you're planning to Get into custom cables as a Business then I can't stress enough how important it is For you to ALWAYS run your first 5 Batches of cables through an intensive Stress test For No less than 4 Hours For each testing duration. If you are serious about providing a Good Product that is Safe and Stable for 24/7 Operation you will need to also Re-run the Entire Testing suite every time you have a Wire or Terminal Pin Supplier Change. This is to First Ensure that the wire or pins meet the specifications and are safe for a PC Use case/ Environment, and Second to Ensure the Manufacturer's Spec Is Validated and Holds up to their Claims. Where Do I Buy These Materials?

Now if you're new to this and wondering "where do I buy all these supplies?" it can depend on where you live but I'll list some global Manufacturers off Ali-Express I use. Links to those Suppliers here:

Red = Required
Orange = Optional
Yellow = Required But Depends on Setup


Pins:
USD 3.60 300pcs 4.2mm Female Terminal Pins
USD 4.05 300pcs 4.2mm Male Terminal Pins
USD 3.51 400pcs 3.0 Small Female Terminal Pins
USD 5.22 300pcs SATA Terminal Pins
USD 4.68 300pcs 4 Pin Molex IDE Terminal Pins

Plugs:
USD 4.50 30pcs Molex 4.2mm Connector Male Plug 2x5
USD 5.40 30pcs Molex 4.2mm Connector Male Plug 2x7
USD 6.30 30pcs Molex 4.2mm Connector Male Plug 2x9
USD 7.20 30pcs Molex 4.2mm Connector Male Plug 2x12
USD 3.60 30pcs Molex 4.2mm Connector Male Plug 8 Pin EPS
USD 4.05 30pcs Molex 4.2mm Connector Male Plug 8 Pin PCIe
USD 4.05 50pcs Molex 4.2mm Connector Male Plug 6 Pin PCIe
USD 6.30 50pcs Molex 3.0mm Connector Small Male Plug 2x6 Pin (NVidia 12 pin)
USD 1.98 10pcs Molex 4.2mm Line Connector R Male Plug 5 Pin
USD 4.05 50pcs SATA Pin-Type Power Connector
USD 5.13 30pcs SATA In-Line Power Connector (90 Cap)
USD 5.13 30pcs SATA In-Line Power Connector (180 Cap)
USD 4.32 50pcs Molex 4.2mm IDE Connector Male Plug
USD 4.50 30pcs Molex 4.2mm Connector Male Plug 4+4 Pin EPS
USD 4.05 30pcs Molex 4.2mm Connector Male Plug 6+2 Pin PCIe

Cable Sleeving Stores
MDPC-X: https://www.cable-sleeving.com/
MAINFrame Customs: https://mainframecustom.com/
ParacordPlanet: https://www.paracordplanet.com/?gclid=Cj0KCQjwmouZBhDSARIsALYcoupBxc7DWWVlyBHDSTDIvx6TpcaRwFoZQgDYPYBIJwtqzi_IpNscaU8aAo9gEALw_wcB
USA Wire Supplier That I use: https://www.remingtonindustries.com/

The Cable-Making Process

If you have Fingers that are Sensitive to Heat then prepare to Feel the Burns! So the process of making cables depends on the Sleeving material you've chosen but for starters, we'll talk about Paracord first as it is typically more affordable and easier to work with. Most 550lbs Paracord includes a 7 strand Core meaning the "Sleeve" is not hollow. That means you'll have to (in most cases) "Gut" the paracord before you can inch it onto the Wire. Thankfully that is very Simple to do, just a little tedious and time-consuming. Let's Walk Through the Process one step at a time with some visuals.

Step 1: Measure the longest length with a piece of wire in the desired Case with the whole PC built (minus the cables). Take that piece of wire and measure against a ruler. Then add about 5% Extra length. The reason why you should add extra length will Become obvious later, Just Trust me.

Step 2: Cut Lengths of wire to the length you just measured. If making a 24-pin cable cut 23 or 24 wires (Depending on if you want a Dummy wire in the blank).

Step 3: Strip one end of each wire and make sure you only strip off 4mm of insulation. No more, No less. Make sure that you strip the Same 4mm length for every wire.

Step 4: Crimp a 4.2mm Female Terminal Pin onto each wire making sure that the wire's insulation is not going into the wire contact crimp.


There is a very easy and Efficient way to crimp your pins onto the wire quickly. The technique is very simple and is shown in this video:

Step 5: Measure a strand of paracord next to your wire and add about 5% Extra length then cut the Paracord and Gut it of the 7-strand core if applicable.

Step 6: Inch the paracord Sleeve onto the Wire past Points 1 and 2 until it reaches right before Point 3 as shown here:

Step 7: Melt the paracord until it Reaches the center of Point 2, then Pinch and twist the Melted Paracord to bind it to the Pin. Video for demonstration:

The end result should look like this:

Step 8: Repeat Steps 5-7 for each wire.

Step 9: Insert the Wires through the cable combs and into the Component end plug and then Plug it into the Corresponding component. Then route the end of the cable that still doesn't have any Pins or a Plug Back to the PSU and Cut the excess length off from the wires so that it's the perfect length. Most likely no 2 wires will be the same length hence why we just added 5% extra length in Step 1.

Step 10: For cables that have Double wires Repeat Steps 3 and 4 for the PSU end wires being sure to crimp 2 wires into 1 Pin for making double wires. For cables with a Split wire Follow the Exert from this Video Linked Here:

Step 11: Repeat Steps 6 and 7 for the PSU end of the wires and then Insert each pin into the plug Being Careful to Follow the Pinout diagram you made from the stock cables.

Step 12: Unplug the Cable from the component then Plug it into a Power supply Tester and then test the cable(s). In order to turn the PSU tester on you must Connect a Compatible 24-pin cable and Then it will power on when the PSU is switched on at the back.

If all has gone well you now should have Cables that are custom Lengths and look very pretty. It goes without saying that this is of course all cosmetic there will be no improvement in air flow as stock cables are not Restrictive enough to Block airflow.

Since I haven't seen a thorough guide yet for making your own USB cables, I decided to make one.  I realize that this doesn't make good business sense since I do sell some of my own cables, but I also like to make things easily accessible to people.  A lot of this community and the computer building community was built on DIYers and their public experiments, so I feel it's only right to help people have easier access to guides that can help them actualize some of their visions. 

I know this is a topic that's a little scary for some people and it does take time and practice to get right, but I figured making a guide might make it a little less scary.  I know that when I started making my own sleeved USB cables (and all the cables to date), it took some work to find some good documentation for the tiered connector on the USB Mini B and for the process of making your own cables.  While there are some guides that are great for sleeving, they don't have a ton of documentation on the connectors and housings.

And a disclaimer, to me this is a fun project to do and gives you a lot of latitude for sleeving, but, depending on how many connectors you get and where you source them from, you might end up spending more than what several of the artisans out there charge for a single cable.  I don't want to discourage anyone from it since it's a fun project and definitely teaches you some things, just expect it to be a little costlier than you'd expect.

Tools you'll need:

- Soldering iron

- Tweezers.  I use these since they're cheap and decent.  You can use any old tweezers.  Finer needle nose pliers might work in a pinch.

Recommended tools:

- Helping hand.  You don't need anything big or fancy, any cheap one will help.

- Painter's tape.  I use this because it doesn't leave a residue.

- Wire strippers.  I use these fairly cheap strippers and they're fantastic.  You can also use a pocket knife, Exacto knife, or razor blade.

- Razor blade for removing the plastic shell from the USB cable and cutting the shielding.

- Adjustable temp soldering iron. This can be something nice like a Hakko 888D or something cheap and dirty like my Weller and home made setup.

Parts you'll need

- USB Cables

- USB connectors and housings of your choice (USB A, USB B, USB Mini A, USB Mini B, Micro USB).  Keep in mind that there are different permutations of connectors, so the number of pads may be different on some and the placement of the pads may be different.  If that's the case, you'll need to try and disassemble the connector to find out what goes where.

- If for a Filco, Molex housing.  You'll need a crimper and the appropriate crimps to do this.

- 3:1 heatshrink

- Sleeving (paracord, MDPC-X, etc).  Be careful with paracord as the sizing is inconsistent and the stuff you buy might be too small to fit over the cable.

Making your cables:

USB A Connector




USB A Pinout

Since USB uses a universal color code, it's pretty easy to make your own cables with an assortment of different USB connectors.  This is a handy little pinout for your common USB A connector.

When it comes time to solder, just match the tinned wires to the right pad and reflow your solder.  If you didn't get enough solder from tinning, it's easy to add a little more. 

I recommend a using some helping hands and tweezers for this task.  I also find it useful to tape the connector down to a flat surface while soldering the wires in place.

Once your wires are soldered properly, I like to add a little hot glue as an insulator and to add a little more strength to the solder joint.



If you get a two part housing like I use, these two little pegs/legs serve as guides for the housing so you get your connector seated perfectly every time.




This the snap together two part housing I use.  Slip on housings are more common.  If you get some of those, ignore this part.





This is the little groove you slide the pegs/legs from the connector into.  There's a little room for wiggle, so don't be worried that the connector isn't gripped tight.


When you slide the connector in, it should end up looking like this:





USB Mini B Connector


USB Mini B Connector Pinout:


Since USB uses a universal color code, it's pretty easy to make your own cables with an assortment of different USB connectors.  This is a handy little pinout for your common USB A connector.

When it comes time to solder, just match the tinned wires to the right pad and reflow your solder.   Take your time and make sure your temps are right.  If you get it too hot, you can melt the pads out of the housing. 

I recommend having a helping hands, tweezers, and some sort of magnifying glass on hand for this. I also find it useful to tape the connector down to a flat surface while soldering the wires in place.

Once your wires are soldered properly, I like to add a little hot glue as an insulator and to add a little more strength to the solder joint.




If you get a two part housing like I use, this little lip serves as guides for the housing so you get your connector seated perfectly every time.


This the snap together two part housing I use:





This is the little groove you slide the lip from the connector into.  If it's not seated properly, the housing won't close.



When you slide the connector in, it should end up looking like this.


USB Wires


Not my picture, but this is your standard USB cable.  You will need to strip the wires and tin them.


In case you don't know what tinning is, tinning is the process of adding solder to your stranded wire that you'll be soldering.  You can either hold the iron at the tip or on the backside of the wire and when it gets hot enough, the solder will flow into it.


More pics to be added later.

awesome guide nubs
like i said before haha 

should save some people money on these cables 

You may or may not save money on the cables making it yourself once you factor in shipping and component prices. It really comes down to how many you decide to make and the prices you can find.

For example, here's a price run down with current prices:

- $1.59 for the USB A connector and housing I use

- $5 for the USB Mini B connectors I use.  You might find a single cheaper elsewhere, but it's not common.

- $5-6 for a USB cable if you don't have a donor cable you can use (that includes the cheap ones from Monoprice since they charge $5-6 for shipping)

- ~$1.40-1.75 + Shipping for 3:1 heatshrink

- $4.80 + shipping for 6' of sleeving of the sleeving I use.  In all reality, this will be closer to $5.60+ shipping since you'll need a little over 6' for a 6' cable.  Even cheap paracord will cost you around this much since you can't find it in under 25' lengths.

- Total - $17.79, not including shipping, probably closer to $25 with shipping.

Like I said, I don't want to discourage people from doing it since it's a good learning experience and it does give you a ton of room to experiment and do what you want, but don't expect it to be cheaper, especially if you have to buy tools to do it in addition to supplies.  It only really becomes cheaper if you plan on making several of them.

As a note, if you clip the fifth mini usb tab that you don't use, it helps in terms of accessing the two tabs below it you do need.

Show Image what I use

Hadn't thought of that, but it that's a great recommendation.  I just keep that tab in case, for some odd reason, someone wants to turn it into a host.

And that certainly does help and makes it easier to double check that you didn't accidentally bridge your data and ground wire.