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Guide: Custom Modular PSU Cables

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Captain Slug

Helpful Senior Member
Joined
May 23, 2001
Location
Asteroid B-612
I did something unique and a number of people have asked that I describe the process used to make the cables in my current project.
http://www.ocforums.com/showthread.php?t=339498

Be warned however. This project takes a considerable amount of time and is extremely tedious. You will need the following tools to accomplish this.

+ Forceps or miniature pliers
+ Drillpress (preferred) or Power Drill
+ Accurate cutting tool (Tablesaw, Bandsaw, or Scrollsaw. NOT A DREMEL)
+ Soldering iron
+ Wire Cutter/Stripper
+ Accurate ruler, hopefully with metric units since you're working with parts made under them
+ Rubber mallet or hammer
+ Sharp implement for punching hole centers

Before starting you need to source parts. The only source I could find that had everything I needed was http://www.performance-pcs.com
Hopefully someone will know of other sources for materials in the US and UK.

1. Cut 20 identical lengths of wire (18awg)
2. Strip 3mm off one end of each wire
3. Crimp on and solder correct pin type.
4. Plug crimped pins into matching connector
baby_mkv_diy_0.jpg
5. Measure connector to find outer dimensions and wire spacings
((The wire spacings for Molex connectors are roughly 5mm, and ATX and ATXP4 spacings are roughly 4mm))
6. Mark measurements onto the edge of a sheet of plastic or aluminum
7. Use an awl, ice pick, center punch, or nail with a rubber mallet or hammer to punch each hole center. Allow some spacing betwen marked connectors on the material so that you can cut them apart. Make sure to double check you measurements. something I forgot to do and subsequently ended up making spacers with 22 holes instead of 20.
baby_mkv_diy_1.jpg
8. Drill out all the holes. 18awg wire will fit snugly through a hole drilled with 3/32-inch bit.
9. Use a scroll saw, jigsaw, bandsaw, or table saw to cut inbetween the marked spacers
10. Cut the spacers from the sheet
baby_mkv_diy_2.jpg
11. Sand the edges of the newly cut spacers as desired
12. Remove the contact paper
13. Thread the wire through the all the spacers
baby_mkv_diy_3.jpg
14. Straighten the cable and double check the lengths of the wires. Cut ends to match as needed
15. Strip 3mm off the end of each wire
16. Crimp on correct pins and solder/heatshrink if required
((If you are wiring a simple molex connector, skip ahead to step #19))
baby_mkv_diy_4.jpg
17. Twist-tie one end of your stock cable. This will represent your unfinished custom cable end
18. Using the stock cable as a template, use the resistance measurement feature on a multimeter to figure out where each wire crosses over from the connector on the other end. Make the same cross-overs on the end of your custom cable and plug the pins into those connector sockets.
baby_mkv_diy_5.jpg
19. Plug remaining crimped pins into matching connector
20. Double-check cable voltages with a multimeter by plugging a standard color-coded extension into the end of your custom cable. Compare your voltage results with a stock cable or another power supply with the same pinout.

Average time to complete
ATXP4 cable: 2+ hours
Molex 4-pin cables: 4+ hours
ATX cable: 6+ hours

As always, measure twice cut once. And more importantly double-check that you're putting the pins where they belong. They're a real booger to get back out if you screw them up.
 
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thanks captain. I dont really understand the whole cross over part. Why do they need to cross over? It seems like it would be just straight through. Did you have to make a PSU modular? I would love to see a guide on that. :)
 
Here are some better pictures of the molex cables and the ATX power cable.
baby_mkv_99998.jpg
baby_mkv_9999995.jpg

threeme2189 said:
well sorry for the "super duper mega ultra noobish" question but what exactly is this mod used for?
Manufacturers are starting offer modular power supplies that allow you to connect only the cables you need.
RyanPower2_1_t.jpg
u10-9510-black-b_t.jpg
svcompucycle_1827_31338033

This allows you to further control the wire management of your computer. They all include pre-sleeved stock cables, but if you're not quite satisfied with the look they offer or you simply want something unique, you can make your own. This guide could also apply to standard power supplies if you're adventurous enough to replace all of its wiring.

facialicious said:
thanks captain. I dont really understand the whole cross over part. Why do they need to cross over? It seems like it would be just straight through. Did you have to make a PSU modular? I would love to see a guide on that. :)
The stock cable for my power supply had a number of COM and +5Vsb lines that were not passing through straightly, and to prevent potential problems I decided to simply duplicate all of the connections. It's also just a good idea to triple-check that your custom cables are outputting the correct voltages in the correct places. If you don't do this part of the process you're definitely going to kill some hardware, and possibly the power supply as well.
 
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I love it. I would do this if I wern't redoing my comp this summer (getting an X-Connect for it). Otherwise, I think I'll look into this for my LAN PC!

~C.P.
 
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