Author Topic: Fixing a Distorted coiled Handset Cord.  (Read 51335 times)

unbeldi

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Re: Fixing a Distorted coiled Handset Cord.
« Reply #75 on: January 22, 2017, 11:36:50 AM »
The Western Electric manufacturing procedure was to wind the cord onto a steel rod and heat it for 8 minutes at a temperature of 268 F to make the coil spring permanent.  After cooling, the coil was rewound in the opposite direction which provides uniformly tight spring coil.

Using flowing heated air is probably a good arrangement as that avoids hot spots by averaging exposure.  In your tube gadget you could probably easily mount a thermocouple to control the power delivered to the heat gun.


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Re: Fixing a Distorted coiled Handset Cord.
« Reply #76 on: January 22, 2017, 11:42:53 AM »
How about using a piece of PVC instead of cardboard, making it a "permanent dedicated" tool?
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Offline andy1702

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Re: Fixing a Distorted coiled Handset Cord.
« Reply #77 on: January 22, 2017, 12:17:46 PM »
I have a slightly different method for restoring cords. I wash them in warm soapy water which relaxes the corl somewhat. To get the tight curl back I reverse the twist one coil at a time. Have a look at the video link below to see how I do it.

https://www.youtube.com/watch?v=Mo3d3WgnoZc

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Offline TelePlay

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Re: Fixing a Distorted coiled Handset Cord.
« Reply #78 on: January 22, 2017, 04:16:20 PM »
How about using a piece of PVC instead of cardboard, making it a "permanent dedicated" tool?

Well, I had the 4" ID heavy duty mailing tube and PVC in large diameter is expensive and heavy. I think the cardboard is a better heat insulator and would also stay cooler on the exterior with room air keeping it cool. It is also lighter in weight but may dry out over time. PVC might heat up more and stay hot longer after use.

I'm thinking of making a permanent tube by putting 1 1/2" or 2" PVC perforated tube down the center of the cardboard tube (they sell perforated drain tubing but it's 4" in diameter - way too large) so will have to drill it myself. In doing so I would not drill 6" on one side of the middle of the smaller tube and I would put a 2" "T" fitting on the center of the cardboard tube for the hair dryer. I'd leave the ends of the smaller tube open but seal off the cardboard tube thereby forcing the hot air to travel through the perforated pipe in a more uniform way before exiting. The undrilled area in the center would be in front of the "T"  which would prevent air from the hair dryer directly hitting the cord in the middle.

The important two things is mounting the dowel in the center of the tube so it does not contact the PVC and making sure there is good air flow with no back pressure which would over heat the hair dryer and cause its internal breaker to open. Spacing of and increasing size of the holes moving away from the center could provide a fairly laminate flow of heat over the cord, similar to the WE hot rod method (the reason why the inside of a coil is is flat), and as long as the holes could handle the hair dryer's CFM output, all should work well.

This is 4" drain pipe.
« Last Edit: January 22, 2017, 04:59:14 PM by TelePlay »
            John . . .

              

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Re: Fixing a Distorted coiled Handset Cord.
« Reply #79 on: January 25, 2017, 05:43:42 PM »
Home Depot sells 2' long 4" diameter (pre-cut) sections of PVC pipe for about $7 - not bad. Yes, they could be used as the outer pipe in stead of a cardboard tube. If doing so, it might work well to wrap the exterior of the 4" pipe some sort of insulating material, (corrugated paper, for example) to keep the tube cool to the touch. The 4" tube is much heavier than cardboard and will retain heat a lot longer, but would work fine with taking precautions.

I also found that a 4" PCV coupler just fits over a 4" mailing tube so I can use that to put around the middle of the cardboard tube and be a firm support for the 2" PVC "T" that will hold the heat gun in place.

I have my drilling guide done so next step is to drill the 2" PVC pipe, assemble all parts and check the heating distribution over the length of the 2" pipe. If uneven more hold can be drilled and other sealed up to get the temperature over the whole 2' pretty much even.

More to come.
            John . . .

              

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Re: Fixing a Distorted coiled Handset Cord.
« Reply #80 on: February 08, 2017, 06:15:45 AM »
Finished construction on the hot air chamber and tried it using a somewhat bent and stretched modular handset cord (yes, no before pictures).

The first picture below is a 44" long, 4" diameter PVC pipe drilled to convey air into and around the inner cord chamber evenly. Half of the very center area was not drilled so the heat gun would not directly enter the inner tube. I used 1/2" holes, then 3/8", then 5/16" and finally 1/4" holes moving away from center.

To come up with a drill hole pattern, I first had to figure out how much air the heat gun was creating. I used a 50 gallon garbage bag to capture the hot air and timed it from start to completely full. Did that a few times to get an average fill. Converted that to cubic feet per second and used that to determine how many square inches in holes to pass the air without backing up and causing the heat gun to overload, to flip its circuit breaker open. The resulting drill pattern is what you see in the first image. Larger holes near the center moving to smaller holes at the end causing most of the air to enter near the middle but letting hot air enter directly at the ends to even out the temperature.

The top of the second image is the completed tube. The 2" diameter drilled tube was placed inside a 2' long 4" diameter heavy cardboard tube using rings on each end to center and hold the tube in the center and to force all hot air through the holes. The center is a 4" PVC connector drilled to accept a 2" PVC T. A 2" diameter hole was drilled in the tube allowing air to enter the cardboard tube where no holes were drilled in the inner tube. The bottom is the end view.

After inserting the cord wrapped on a wood dowel, with the modular connectors covered with soft foam, the dowel was centered using 22 gauge wire run through 1/8" holes in each end, enough to allow centering of the dowel.

Put the hair dryer in the "T" and turned it on low, same setting as my above experiment. It took about 5 minutes for the air coming out of the end to stabilize at about 145 F. At that point, the cardboard tube stabilized at 120 F near the "T" and 110 F at the ends. After 25 minutes from stop, I realized using the low setting with this air tube resulted in a lower temperature than forcing the air into an end - probably better air flow. At that time, I turned the heat gun on high and in about 5 minutes, the temperature reached 185 F. At that time, I put a rag over each end, turned off the heat gun and securely covered the ends to keep the hot air in the tube.

Let it cool naturally for about a hour. The cord, when removed from the dowel, looked like NOS. The bottom image shows the cord on the phone and as it looked after taking it off of the dowel.

Next time I'll take before pictures, now that I know this will work as planned. Total cost, less than $10.
« Last Edit: February 08, 2017, 04:08:42 PM by AE_Collector »
            John . . .

              

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Re: Fixing a Distorted coiled Handset Cord.
« Reply #81 on: February 08, 2017, 04:13:29 PM »
Pretty impressive John! Are you going to be the "coil cord restoration guy" like Steve Hilsz is the dial guy?

Are you using a hair dryer or the commercial type heat gun?

Terry

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Re: Fixing a Distorted coiled Handset Cord.
« Reply #82 on: February 08, 2017, 04:43:51 PM »
Pretty impressive John! Are you going to be the "coil cord restoration guy" like Steve Hilsz is the dial guy?

Are you using a hair dryer or the commercial type heat gun?

First, thanks. Much more controlled than using a kitchen oven. Then, . . .

1)  No.

2) Using a 1875 watt hairdryer that was extra so ended up in the dungeon. On the low setting, it should last for some time at a half hour per cord. Will get a commercial type when this one gives out.


One thing that this method has going for it is that the cord was once coiled so it's not like turning a straight, round cord into a coil. The coiled cords still have a good percentage of coil in them so this is more of a touch up, a get it back to near original fix.

Have to do a few more cords before I become convinced that this is better, or easier, than sticking it in an oven - which also works.
            John . . .

              

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Re: Fixing a Distorted coiled Handset Cord.
« Reply #83 on: February 08, 2017, 05:29:13 PM »
Had anyone else tried just twisting it backwards rather than going to the teouble of heating it up, because this definitely works well on UK cords.

Andy
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Re: Fixing a Distorted coiled Handset Cord.
« Reply #84 on: February 08, 2017, 08:55:39 PM »
Had anyone else tried just twisting it backwards rather than going to the teouble of heating it up, because this definitely works well on UK cords.

I did twist it backward first, before heating, and all I got was the same issues in reverse - gaps, bends, big coils.

That all went away after heating on a dowel. Next cords I do (I'll take before and after), I will twist one before heating and the other not to see what difference that makes.

The heat method has been proven to work for cloth and non-cloth cords. Some reverse twist after heating. Reverse twisting won't fix an elongated coil or group of coils. Reverse twisting can help with spacing of the coil but does nothing for bends and stretches. At least, in my experience of working with cords.

Just adding a way to heat should anyone care or want to do the same. It's a lot easier to stick a wrapped dowel inside a tube and turn on a hair dryer for a half hour than deal with a hot oven.
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Re: Fixing a Distorted coiled Handset Cord.
« Reply #85 on: February 09, 2017, 03:51:27 AM »
That's very interesting because stretched cords on UK phones (plastic cords) always seem to go back into a tight coil just by reversing them.
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Re: Fixing a Distorted coiled Handset Cord.
« Reply #86 on: February 09, 2017, 11:11:42 AM »
Here too but I think the problem is when a cord has a reversal of the coils somewhere in the middle that has been that way for a long time. Up to the point of the reversal may have tight coils and then loose coils from there on. There is no way to remove the reversal in the cord as one side will always be loose and the other tight.

A cord that is simply stretched out without any reversals in the coils can be wound backwards to tighten it up though it always seems to me that it then comes out of the handset facing the wrong direction initially which makes it likely that the coils will reverse there with use.

Terry

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Re: Fixing a Distorted coiled Handset Cord.
« Reply #87 on: February 23, 2017, 08:08:52 AM »
Had a coiled cord from a 1500 which had tight, uniform loops but 2 in a row were bent at a 45 degree angle. Didn't take a before photo but after heating it up to 150 over 15 minutes and then turning the gun on high to get the temperature up to 190, I covered each end with a rag, turned off the gun and let it cool naturally for about an hour. Kink is gone, cord looks like NOS. The coiled cord "oven" works well. Will take before photos next time.
            John . . .

              

Offline cloyd

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Re: Fixing a Distorted coiled Handset Cord.
« Reply #88 on: September 04, 2017, 10:10:35 AM »
Yet another great set of posts Teleplay!

The first picture below is a 44" long, 4" diameter PVC pipe drilled to convey air into and around the inner cord chamber evenly.

I had a hard time visualizing your description until I thought that your reference to the 4" PVC pipe should have said 2" as is mentioned later in the paragraph.  Is that correct or am still confused?

Thanks!

Tina Loyd
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Re: Fixing a Distorted coiled Handset Cord.
« Reply #89 on: September 04, 2017, 03:59:48 PM »
Yet another great set of posts Teleplay!

I had a hard time visualizing your description until I thought that your reference to the 4" PVC pipe should have said 2" as is mentioned later in the paragraph.  Is that correct or am still confused?

Thanks!

Tina Loyd

It's made from 2 different pipes. The 4" heavy cardboard tube is the "outside" of the "oven" with only one large hole in the center to allow the hot air to be blown in.

The 2" PVC pipe had many holes drilled into it to allow the hot air entering the the 4" tube to pass through or enter the 2" pipe evenly so one part of the cord does not get hotter than the other parts.

The handset cord is wrapped tightly around a dowel and place inside the 2" pipe as close to center as possible. I use station wire and holes drilled into the end of the 2" tube to do this.

Over all, this setup allows hot air to evenly enter the 2" pipe and exit out the ends.

Picture from the end shows all except the center dowel that would hold the handset cord.
            John . . .