Building a RJ-45 Ethernet cable of a
specific length (light version)
As usual, I cannot be responsible for any damage to
your machines when you will experiment the following
Objective: to build a small Ethernet cable (max 15 cm of
cable) to get rid of long cables which burden your
desk...for instance to connect an airport station to a
router or to connect any element to a network...i mpatient
you are after reading this
(in french), or this
(also in french)...
First of all, you need a class 5 cable (see specialized
One can also shorten the cable included in the router
Ah yes: we need a special tool to crimp the RJ-45
connectors... let's say around 15 euros.
From the tool's hinge up to its handle: blades to denude
the cable, the crimping metal pieces and a cutting area.
As far as the crimping only part of the job is concerned,
I use this tool.
RJ-45 connectors and coloured caps; the latter helps to
protect the ethernet connector as well as they differentiate
the cables in the muddle of cables a network can produce!
If the caps are used (optional), they, of course, have to
be placed on the cable's ends before crimping the
Connectors can be of various types: with/without guides,
These ones are simples.
We see here the metallic pins which will be inserted in
each of the cable's wires.
I do not use the cutting blades of the tool described
above to remove the plastic coat which protect the cable's
I use a cutter and I make an incision at 2/3 cm from the
Doing this, I'm sure that the wires will not be damaged
and that their length will be sufficient to untwist them!
Untwisted... easier to operate no ? :-)
Down flat... and in the right ordre to be manipulated;
from left to right:
To build a "direct" cable, both cable's ends must be in
To build a "crossed" cable, one end like the one above,
the other end as the following:
- white/green <-
- green <-
- white/orange <-
- orange <-
You see that, from the straight configuration, we permute
"white/green" and "white/orange" on one hand ,
"orange" and "green" on the other hand .
These two pairs are the ones which are used in a base-10
or base-100 or base 1000 connection.
Other wires do not carry signal in the connection.
After cutting the wires, we insert them into the
connector like this.
... up to the pins at the end of the connector!
Push the girdle firmly up to the metallic pins...
... like this: the wires are well placed on.
The yellow arrow points to the contacts which will go
fixed into the the conducting parts, the blue one shows the
plastic lug which will lock the conducting parts and their
coat into the connector.
And plug the connector into the crimping tool.
Again, we check that the cable and the girdle are well
placed before crimping them.
The cable is ready...10 cm long as the webmaster of
requiers it. But this cable is quite rigid and as the
network's components will be surimposed, a little gap
between such home-made cables will be required to avoid