A good way to protect your cables when installing the electronics into a RC Helicopter is to add braided sleeving.   This also gives a nice professional looking installation.

 Here I show how I do this.

 So in this example I am using an antenna extention for my Spektrum radio.

The braided sleeving I use comes from http://cableorganizer.com.

 The first step is to thread teh extension cable ito the raided sleeving.  To make the easier I use a pair of forceps with a pointed tip that I thread into the braid to open it up.  I then thread the connector and cable into the braid as shown below.

The next step is to add the heat shrink tubing for each end.  As often is the case to use the correct tubing for the cable size will mean that you may have difficulty getting it past the connectors. 

One solution will be to cut the cable which unless you intend to either lengthen or shorten the cable is not really desireable.

 So what I do is to use a pair of scissors to stretch the tubing.

I do this to both ends of the tubing which should then allow you to get it over the connector.

 
Finally, I use a heat source to shrink the tubingat each end and there you have it, a antenna extension protected by braided sleeving.