Friday, December 16, 2011

Flex cables - sometimes nightmare for DIY

I like to take appart anything that has electronics inside. I like seeing how it works. I also sometimes try to modifiy it, or just take out components that I need in my projects. That's how I end up with a large inventory of used electronic components and one of them is a big pile of flex cables. These are commonly found in any modern electronic system like scanners, printers and many other hardware.

You probably think, what on the world will I do with so much flex cables? In diy projects they are useless because of the limitations of our home tools in soldering. Well I do admit I rarely use them in my DIY projects, but when it comes to repairing some other hardware they do come in handy... 

Sometimes happens that flex cables ware out, because of constant streching and bending. One example of this is in the CD player where a flex cable is used to connect electronics with a laser and a pick up sensor. Now you could go and find a brand new one on ebay, but the most likely part is that you will not find it or it will be ridiculously expensive.

When it comes to that, I go and check my big pile of flex cables for the same or more number of wires and IMPORTANT - SAME PITCH SIZE.

I found one cable from Sony that met my application.


Now we have to cut this cable to meet our applications number of wires. I needed 16 wires, but as you can see from the picture bellow, there are 17 wires. This is becase the width of the cable must also meet our application and that means that we will have one extra wire that we will slightly trim to fit in our connector. This does not cause any problems in our system and so we can leave it the way it is.


Now we have to cut it to the same length on one end.


Now comes the tricky part. We must remove the isolaton to expose the wire. I found that this is best done with a fine wire mesh on my power tool. Tape the wire down with some duct tape and carefully grind down plastic isolation. 



When you are done it should end up looking like this:


Now all I we have to do next is glue a peace of hard plastic on to the lower part of the wire with some super glue and trim down the exces.


It does not look pretty I know that, but it gets the job done. I used it to repair a CD player from Teac and it worked perfectly. I also suggest that the end that we have made, is used in our application where it is least under stress. That is why I plugged my DIY end in the main board of CD player and the other industrial made endto the laser module, where it will undergo  a bit more stress in bending.

If someone knows a better way to remove the plastic isolation from a flex cable I would really appreciate it if you leave a comment. 

6 comments:

  1. I used a razor blade to remove the plastic on the flex cable of a laptop keyboard. It was attached with adhesive, and I was able to carefully peel it off.

    ~torpid tyrant

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  2. Thank you for your reply. Yes it is a way but I think there is alot of hassling with that... Does anyone know of some sort of a chemical? Or any other method.

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  3. That's how I do it. Razor blade the top and bottom then just slide it off the end.

    BTW, you say flex cables have no great use in DIY... not true! Anytime I need to run more than 3 wires together, I pull an old flex cable out of storage! (for 2 wires I use twisty pairs or double stranded cable, for 3 wires I use shielded twisty pairs)

    Hack the end off according to the above, split the wires about 3" or so, then start soldering to your arduino or whatever!

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  4. I did not say they have no great use in DIY but it is true that it is allot easier without them in DIY projects. I will try the method with the razor but I think there is rather a large chance that you also cut the wires or at least damage them. But ok.. Practice makes perfect :)

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  5. In DIY projects to make PCBs, Acetone is used to remove the plastic toner mask. Maybe leaving the bottom part in an Acetone solution for a bit might work?

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  6. Will definetly try this method... Maybe it will work... Thank you for your comment

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