Introduction: Make Custom Cables With Hot Glue and Shrinking Tube

I own a WRTnode board - a very interesting 600MHz development board for OpenWRT distribution. So instead buying a WiFi router able to run OpenWRT and start disassemble it and soldering various cables, you can use WRTnode - all the signals are accessible out of the box. WRTnode can boot your personal OpenWRT compilations straight from USB stick, so you will not harm the board. (details about the board on http://wrtnode.com/ - PS: I am not WRTnode team affiliate).

Somehow I managed to brick the board, I did my best to fix it, eventually I had to make 2 cables: one cable for serial connection (made from a Nokia mobile phone USB data cable) and a second cable for Ethernet connection (one end has a RJ45 connector). WRTnode has 2 rows pin header (male) with useful signals: 3V3, 5V, GND, Ethernet, I2C, SPI, serial Rx / Tx, USB and so on. In order to connect to these signals, I had to use 2 rows headers female on my cables.

Just an observation: comparing to USB-to-serial modules, it is cheaper and less time consuming to use such mobile phone USB data cable, just cut the end phone connector, solder the wires to your connector and that is it.

I soldered the wires from my cables to the female headers according to the WRTnode pin map, but the cables are not looking very good and also I am not sure these will last long time.

Searching for Instructables, I found ideas to use shrinking tube, hot glue, Sugru, insulation electrical tape... Some ideas were looking good, some not, some were simpler and so on.

So why not combining shrinking tube, hot glue and a hot air gun in order to make some long lasting cables with header connectors (and maybe for other connector types)?

Step 1: First Attempt Using Hot Glue and Shrinking Tube

My idea was simple:

-the hot air gun will melt / soften (again) the hot glue inside the shrinking tube

-the shrinking tube will shrink and it will distribute the hot glue evenly inside the tube (even filling air gaps)

-afterwards I can give a shape to that end of the cable.

Things went fine until I noticed that hot glue is coming out of the connector's holes because: hot glue melted inside the shrinking tube, shrinking tube shrink and pushed the hot glue to the path of minimal resistance :)

So back to the drawing board!

Step 2: Second Attempt Using Hot Glue and Shrinking Tube

Solution to the problem:

-use machined headers, these have no holes

-block the holes somehow.

I had to take choice number 2.

I took a sheet of paper, I punched the connector's pins to the paper and trimmed the paper to match connector size.

I soldered the wires, I checked the cables (connect them to the PC and to the WRTnode and see that are working from an electrical perspective).

After I was sure that these are working cables, I put hot glue, left it a while to harden, then put the shrinking tube and use the hot air gun.

Step 3: Lesson Learnt

As you can see, cables are looking good, definitely they will last longer.

Lesson was: never squeeze hot glue, it will go outside if there is a hole! (pretty obvious, isn't it?)

Comments

author
JustChill (author)2016-03-31

Great tutorial! The final product looks good too. Just to check - what is the purpose of having the paper at the header?

author
CatalinRO (author)JustChill2016-04-01

When you warm the shrinking tube with the hot air gun, the hot glue will melt and the shrinking tube will push it to the least resistance path, so you will see the hot glue coming out on the other side of the connector. The paper will stop the hot melt to go inside of the connector (there is an image depicting this fact). Thank you for your appreciation!

author
Crypter made it! (author)2016-02-28

I was right about to write an instructable about this when I came upon yours :D
Great idea! Every cable I repair, like the micro-usb charging cable I have, is done the same way, and they never fail even after years and years of daily use.

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author
CatalinRO (author)Crypter2016-02-29

For sure I did not invent something new, just I described what I did, someone else may be did it in a more elegant way. You gave me a good idea: I'll make a real micro USB charging cable with real tick wires, most of the cables I measured are too thin and there is a voltage drop across them and it does not matter if you have a USB charger able to supply 2-3-4 Amps if the cable cannot transport it to you device. Thanks :)

author
Crypter (author)CatalinRO2016-03-01

I'd recommend using a twisted pair if possible, not longer than 2m. 20AWG is already an overkill, 24AWG will be just fine. There's no product that will draw more than 2A from a USB port, not with the teeny-tiny micro USB connectors on the other end. I'm planning on creating a 5A dual output car charger that can simultaneously deliver 2.5A across two devices, so I did a lot of research on this field.

Also, a hint when creating cables, make diagonal cuts on the insulation of the cable if possible, when he hot glue melts it will flow between the cuts and bond better with the cable. Later, even pulling the cable out of the socket will be much safer.

author
CatalinRO (author)Crypter2016-03-01

For me look like the existing charging cables are meant to replace some electronic circuits which should limit the current: a thin wire will not let you draw too much current, so no need for fancy electronics :)

author
Crypter (author)CatalinRO2016-03-03

I broke the connector today, unintentionally, and I wanted to check how good the seal was. I couldn't even cut it open, it's that strong!

The hot glue melts and bonds with the shrink tube completely. It has molten between all the connections and wires, making it completely water proof. You can't re-use the connector later because of this.

I highly recommend this a method for creating strong cables that will last!

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author
CatalinRO (author)Crypter2016-03-03

That is something to keep in mind. I wish that the cable manufacturer would copy this :)

author
MBHTMMTPZTAYIO (author)2015-04-17

i cant find 5 volt pin from that board

author
abuhafss (author)2014-12-17

Great idea to have customized connectors at very low cost.

Keep it up.

author
ninjanody (author)2014-11-17

Nice idea. After soldering i put shrink tube to each of the cables and then a bigger one to keep them all toggether.

author
catacris2003 (author)2014-11-12

Felicitări, frumoasă prezentare.

author
CatalinRO (author)catacris20032014-11-12

Multumesc! :)

author
MsSweetSatisfaction (author)2014-11-09

The cables look great, ver clean and protective!

author

Thank you! If someone will try it, I am curious about making the cables at an angle, sharing images with the angled connector will be great.

author
carlos66ba (author)2014-11-09

These cables look absolutely great! Thank you for sharing this excellent idea.

author
CatalinRO (author)carlos66ba2014-11-10

Thank you! The version without shrinking tube is really bad looking.

author
poelma (author)2014-11-09

Great Idea, will have to experiment.

author
CatalinRO (author)poelma2014-11-10

Thanks, you are correct: experiment, maybe first time won't work as expected, but the second try should do it :)

About This Instructable

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Bio: I like making things, trying to utilize my hands and my brain. There is no limit!
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