Restoring a coiled cable

[engicoder]

I picked up an IBM Model F XT recently. The board itself was in very good shape, but unfortunately, it had been stored for years with the cable stretched and wrapped around the board. As a result, the cord was permanently stretched, the tight coil that it originally had was long gone. Following is the process and results of my attempt to restore the original coiling.

Process:

• Thoroughly clean cable.
• Wrap cable tightly around 3/8" wood dowel. (I used aluminum wire to hold the cable to the dowel)
• Suspend in preheated 250F (93C) oven
• "Bake" for 2 hours.
• Plunge in ice bath for 1 hour.
• Place in freezer for 1 hour.
• Allow to return to room temparature.
• Remove from stick.

Photos:

• Before:
  
  
• On the wood dowel:
  
  
• After:
  
  

Results:

I am very pleased with the results. The resulting coil looks very much like the original. Time will tell if it holds up to being stretched on occasion.
When they are produced at the factory, they reverse the coil which is supposed to give the coil more spring due to the stresses created. I did not try that yet as its a PITA with an assembled cable.

[chyros]

Wow, that's excellent! Very well done, it looks really nice!

I might try this method myself if I get a board someday that has a stretched cable like this...

[jdcarpe]

Very good info! I feel like this should be in Making Stuff Together, even though it's technically restoring, not making.

[Muffin860]

Wow! I'm definitely bookmarking this for layer use.

[engicoder]

Very good info! I feel like this should be in Making Stuff Together, even though it's technically restoring, not making.

I debated that myself. Where is "Fixing broken S&%$" sub forum? 

[E TwentyNine]

I've done this a little simpler with a sink of hot water, then in the freezer, then letting it stay on the dowel for a few days.

Has held up for over a year.

[fohat.digs]

I've done this a little simpler with a sink of hot water, then in the freezer, then letting it stay on the dowel for a few days.

That cable looks fabulous!

I have tried an even more minimal approach, because I have come to fear immersing wires in water - in my mind's eye I consider the water wicking back into the braided cable by capillary action and causing corrosion at the joint, and behind it, over time.

The dowel wrap is exactly what I did, but I simply gave it a few hours of direct sunlight on the porch rail and then left it wrapped on the stick, indoors, for about a week. It was a huge improvement, if not 100% perfect.

[jwaz]

I was just contemplating the best way to accomplish this the other day. Great work engicoder

[engicoder]

I've done this a little simpler with a sink of hot water, then in the freezer, then letting it stay on the dowel for a few days.

That cable looks fabulous!

I have tried an even more minimal approach, because I have come to fear immersing wires in water - in my mind's eye I consider the water wicking back into the braided cable by capillary action and causing corrosion at the joint, and behind it, over time.

The dowel wrap is exactly what I did, but I simply gave it a few hours of direct sunlight on the porch rail and then left it wrapped on the stick, indoors, for about a week. It was a huge improvement, if not 100% perfect.

I've read about several people using the sun method, so seems like an equally valid method. One put the cable wrapped on the stick on the dash board of a car in the sun.

I shared your fears about water. When I quenched the cable in water, I made sure the ends stayed dry and only submerged the coiled portion.

[engicoder]

I've done this a little simpler with a sink of hot water, then in the freezer, then letting it stay on the dowel for a few days.

Has held up for over a year.

I read about this method as well. I wasn't sure how hot the water should be. Seems like boiling would be ok, considering I was baking at well over boiling temperatures. What temp did you use.
I though baking would work better since the temp would rise more slowly and would have a good long time to re-arrange the molecular bonds, etc, but sounds like the hot water method worked fine for you.

[fohat.digs]

When I quenched the cable in water, I made sure the ends stayed dry and only submerged the coiled portion.

On rare occasions when I feel the need to use soap and water on a cable, so I use the corner of a baggie and a rubber band to keep the ends dry.

[E TwentyNine]

I read about this method as well. I wasn't sure how hot the water should be. Seems like boiling would be ok, considering I was baking at well over boiling temperatures. What temp did you use.

Straight out of the tap.  And I kept the ends out of the water.

[engicoder]

I read about this method as well. I wasn't sure how hot the water should be. Seems like boiling would be ok, considering I was baking at well over boiling temperatures. What temp did you use.

Straight out of the tap.  And I kept the ends out of the water.

Thanks for the info.

[Skechup]

Oh man, that's an awesome idea.

I was thinking about how to fix coiled wired which had been stretched but never did I have an idea which is this efficient!