Multi Wire Cable Splice/Repair Advice

Thread Starter

wongojack

Joined Jul 19, 2013
12
Hey folks - it has been a long time since my last post. I was tinkering around and repaired a very old game controller cable that had a short in it. This one happened to only have 4 wires inside. I got it fixed, but it was really tough to get heat shrink tubing around the little interior wires without it melting pre-maturely and then get all the connections separated. I ended up with a working cable that has a pokey, lump in it.

What is a better way? Is liquid tape a good option? Should I stagger the solder points? Do I just need to strip the wires back farther to get the heat shrink on there without melting it during soldering?

This cable WILL bend, so how should I cover the work area to "finish" it off?
 

Yaakov

Joined Jan 27, 2019
3,501
If I need to make an inline splice on multiconductor wire, I stagger the joints and use marine grade heatshrink over the while thing without individually insulating the splices.

This can be relatively small, but it will not be very flexible. If you need flexible, consider replacing the cable entirely.
 

Yaakov

Joined Jan 27, 2019
3,501
By the way, the reason for the marine grade shrink tube, if you aren't familiar, is that it has a low temperature melt adhesive lining that will fill the gaps and insulate around the splices.
 

Thread Starter

wongojack

Joined Jul 19, 2013
12
Thank you for the responses! Unfortunately this is a 30 year old cable and the joystick connector at the end is kind of hard to replace as it is one of those that is molded nicely to fit into a game console. I don't really want to sacrifice the original cable.

I had considered putting a small junction box over the work to try and keep that specific place from bending, but that doesn't seem to be a common technique.
 

Yaakov

Joined Jan 27, 2019
3,501
Thank you for the responses! Unfortunately this is a 30 year old cable and the joystick connector at the end is kind of hard to replace as it is one of those that is molded nicely to fit into a game console. I don't really want to sacrifice the original cable.

I had considered putting a small junction box over the work to try and keep that specific place from bending, but that doesn't seem to be a common technique.
The splice I described won't flex but it won't be hurt by an attempt either.
 

Yaakov

Joined Jan 27, 2019
3,501
Just to be clear:

To make the splice you will need to strip about 1” of the outer jack on each side.

Next cut a piece of the tubing that will overlap the entire splice by at least ¼” on each and an pass it onto the longest side and out of your way. DO NOT FORGET TO DO THIS BEFORE CONTINUING.

Next cut the conductors in complimentary stair step fashion, each a bit more than ¼” longer than the other (i.e.: shortest would be ¼”, then ½”, then ¾”, then 1”), complimentary meaning the shortest color on one side would be the longest on the other, etc.

Next, carefully strip about ⅛” of insulation from the end of each. Gently twist the wires to they form a unified conductor but just gently. Then, being very careful not to overheat the insulation tin each wire (that is, coat them in solder). There will be “melt back” as the wire heats up. The extent will depend on the insulation type but you must be very careful not to overheat the wire when tinning. If you have a non-corrossive flux, you should use it.

Next, lay out the two side so the corresponding wires line up. solder together the two outermost wires carefully maintaining the alignment of the ends. Be careful not to add too much solder. Use only enough to start the heat transfer between the tinned wires while will have solder on them already, don’t glob it on. If you get a bit of excess don’t be concerned But keep it to a minimum.

NOTE: Be very careful not to short the connection to the next wire by melting its insulation. If the insulation is easily melted, place something (kapton tape, thin metal, etc.) between the joint you are soldering and the next wire. If you have to, you can flex it out of the way while you solder. Just make sure you maintain the final geometry when it is finished. If you accidentally do melt the adjacent insulation, a small piece of vinyl electrical tape entirely around the area will insulate it with only a small disturbance in the splice.

Be prepared to mess this up once, If you do, trim away to he shortest conductor, and restart. This will preserve the maximum amount of cable. TAKE YOUR TIME. You don’t have to go fast. Be careful, double check everything. Practice on other wire if you can. Make sure your soldering iron tip is clean and a good size.

Let me know how it works out.
 

Thread Starter

wongojack

Joined Jul 19, 2013
12
I ended up practicing on a nine-wire cable that I was working on for something else just to get a feel for spacing out the individual splices and deciding if I wanted to use heat-shrink on the interior wires. I DID end up using small tubes of heatshrink, and it was hard, but the alternative was to space out the splices farther and I didn't want to do that.

Anyway - it worked. I re-wired 2 different 9 wire cords for a different project and I fixed the old Atari paddle wire just fine. They are a bit lumpy but don't have any sharp angles and follow the natural contour of the cord.


FYI - BELOW IS NOT MY WORK

One question I did have is about adding additional strength to the cord. I see things like "repair wraps" advertised and I wonder if any of those are worth it. Someone who worked on a project similar to mine used these below. What are they called?

Inty2_adapters_02R.jpg


Colecovision_Y-adapter.jpg
 

Thread Starter

wongojack

Joined Jul 19, 2013
12
Hmm . . . heatshrink over split loom. I hadn't considered that. I have a message out to the person who did this to see what they say.
 
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