I had a chance to go through another instrument cable crafting session and used the traditional method for clamping the ground lug to the cable and shielding braid this time. This method makes for a stronger connection since the lug is clamping to the tough outer insulator of the cable instead of the shielding braid. I thought I’d make a mini tutorial on doing it this way to compliment my other guide. This guide will be linked to from the other guide as an alternate method. Let’s get started.
Stripping the Cable
This time we’ll be stripping the cable a little differently. See the following illustration. This photo is a bit clearer than the one in the other guide. You can clearly see the different layers that have been stripped. First we removed about 3/4″ from the outer insulator only. Then we fanned out the copper braid that was exposed by pulling it all one direction around the cable and then the other direction until it was fanned out all the way to the orange insulator. Then we pulled it all to one side and twisted it together into a single lead.Next we stripped the tip down to the core wire just enough to make a good lead for connecting to the hot lug on the plug. Then we removed the thin black layer of conductive insulation to expose the non-conductive clear plastic insulation below. This is important to keep from shorting the circuit.
Soldering the Connection
Here we oriented the shield strand so it lies against the long flat arm of the plug. Then we crimped the wings closed to hold it in place. You can solder this joint if you like but it’s not really necessary. If you get it well crimped it will stay in good contact with the shield wire. Then I used my butane iron to solder core wire to the hot lug on the plug.
Potting the Connection
Here you can see how we filled the open area of the connection with hot glue. This eliminates movement at the joint and provides for longer cable life.
Heatshrinking the Connection
Here we are going to apply the heat shrink tubing to the connection to encase the whole thing for a neater appearance and stronger cable head. I’m using 3:1 ratio 3/8″ heatshrink tubing. This stuff starts out 3 times larger than it shrinks to. This makes it easier to get into place over the components of the plug and still shrink up to a nice tight fit. I’m using my Zippo type lighter since I still haven’t bought a heat gun. With a lighter like this you can set it down once lit and use both hands to control the cable you are shrinking.
You don’t want to get the cable right in the flame. Hold it an inch or two above the flame and let the heat do the work. Keep the cable moving as well so it doesn’t scorch and gets heat evenly. The heat will remelt the hot glue inside and allow the heatshrink to draw the glue down to a nice uniform thickness around the components.
I pass the heatshrink directly through the flame very briefly at the end to make sure it is fully shrunk. You may have to wipe a little soot off the cable if you do this.
All that is left is to place the hard plastic insulator and the metal casing back over the plug.
That’s it. We’re all done. To finish up the other end of the cable just repeat this procedure. Just remember to place the metal housing, the clear insulator, and the heatshrink on the cable (in that exact order) before starting to solder the other end. You’ll have to take it back apart if you don’t since you can’t put them on afterwards.