How do I make my own RJ-11 or RJ-45 cable?

NOTE: Article not complete. Coming soon:

  • Photos
  • Links to pinouts for specific cable types

A: You’re going to need a few items:

  • RJ-11 or RJ-45 crimper with built in cable cutter
  • RJ-11 or RJ-45 connector tips
  • a resource to look up the proper pinouts for the cable you’re making

After you’ve got the necessary items together, strip the outer jacket of the cable at both ends, arrange the wires and crimp them into the connector tips. Be sure to check your work, as it is very easy to make a mistake.

SUMMARY:

  1. Pick your cable type.
  2. Cut both ends cleanly.
  3. Figure out the connectors going on each end.
  4. Strip the jacket from one end.
  5. Arrange the wires as needed.
  6. Put the arranged wires into the connector tip.
  7. Crimp the cable.
  8. Check your work.
  9. Repeat Steps 4 through 8 with the other end.

DETAILED:

For this example, I’m going to be building a serial cable to manage a Sun StorEdge T3 array. But this tutorial has been written generally enough that you can use the principles outlined below to build any type of cable that uses RJ-11 and/or RJ-45 ends.

1. Pick your cable type.
The first step is to select the type of cable that we can use. Since I’m going to be making a T3 serial cable, I’m going to make my life easy and use a 6-pin telephone cable. I could just as easily make this cable with a standard 8-pin Ethernet cable, but using the telephone cord is going to make my life a whole lot easier for this example.

Note: An important part of crimping cable — at least until you get practiced at making it — is to start with a length of cable which is at least 6 inches longer than you’re going to end up needing. For example, if you need a 6-foot cable, start with a 6-and-a-half foot length of cable. There are several reasons for this — you may crimp the cable with the wrong pinout or you may inadvertently cut the cable. It’s always good to have extra length to work with in case you have to start cutting ends off.

2. Cut both ends cleanly.
Ok, so assuming you’ve got your appropriate cable length, you need to make a clean cut on each end with a cable cutter — or with a crimper that has a cutter built in.

3. Figure out the connectors going on each end.
Once you’ve got your two ends with clean cuts, you need to figure out what tips ends you’re going to be putting on each end. For this example, I’m going to need a 6-pin RJ-11 connector on one end and an 8-pin RJ-45 connector on the other end.

4. Strip the jacket from one end.
The next step is to remove the outer “jacket” of the cable from the first end. To do this, use the cutter that you used to cut both ends cleanly in step 2. However, this time, you don’t want to cut the cable all the way through. You want to only pierce the outer jacket so that you can then pull it off.

5. Arrange the wires as needed.
Now that you have the outer jacket off of the cable, you can re-arrange the wires inside the cable as needed to give you the proper pinout needed for your cable. In this example, the telephone cable is already organized the way I need it, so I can just proceed to the next step.

6. Put the arranged wires into the connector tip.
Once you’ve arranged the wires as needed, slide them into the connector tip. Make sure you view the connector tip from various angles (sides, top, bottom) to make sure that all the wires have made their way completely into the connector tip

7. Crimp the cable.
Once you are sure the wires are all the way inside, you can proceed to crimp it. One thing you might want to be aware of is that the cable can start to slip out of the connector before you’ve actually crimped it. As such, I always like to make sure I’m exerting a little inward pressure on the cable to prevent that from happening. Make sure to close the crimper solidly, but don’t squeeze with the death grip, as you could end up cracking the connector tip.

8. Check your work.
After crimping, you want to check your work and make sure that (a) the wires are still all the way inside the connector tip, and (b) the pins have pierced the wires completely. To to this, you again want to view the connector tip from sides, top and bottom and visually confirm that the wires meet the criteria outlined in (a) and (b).

9. Repeat Steps 4 through 8 with the other end.
Now that you’ve finished first side of your cable, you’re going to want to repeat those steps with the other end.

Some side notes: (a) In my example cable, I need to put an RJ-45 connector on the other end. In order to make my life easier, I like to take some “scrap” wires and insert them into the unused slots in the connector. This way, my arranged wires can only go into the slots that I mean for them to slide into.

(b) When arranging the other side, I need to move wires from one side of the cable to the other. To do this, I like to give the cable a pinch so that it’s easier to move the wires around and arrange them as needed.

PS: Don’t forget to stop by AnySystem.com for all your Sun hardware and consulting needs.

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