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Large Electromagnetic Jig Project

  1. Dec 4, 2013 #1
    Hi all, I am looking at the possibility of creating a large magnetic jig for making up wiring harnesses.

    Currently we use wooden boards 2400 x 1200mm and simply put a full size drawing of the wiring harness on it and bang in nails. Although this is OK for some harnesses it is not ideal. We previously used roofing bolts and made permanent jigs but found that this was wasteful and storage was a problem.

    The idea is to have a metal sheet of say for arguments sake 1000mm tall and 2000mm long.
    Then lay on the fullsize drawing of same size, lay a thin sheet of perspex or similar clear plastic over the front to keep the drawing in place and protect it.
    then we would simply place some kind of pre made blocks with a 4" peg in it to hold the cables while they were placed on the jig to create the wiring harness shape.

    These blocks would have to be held in place magnetically so therefore I thought that we could somehow create an electromagnetic jig board perhaps with 2 settings.
    Setting 1 to place the magnetic blocks and to have enough pull to hold them on the board but to allow them to be moved around easily.
    Setting 2 would then presumably put more current through or turn on an additional circuit to hold the blocks tight.

    We would then assemble the harnesses, remove the harness, flick the switch the blocks would drop off the board (or become very easy to remove) and put a new drawing in to start the process again.

    One thing that crossed my mind is the fact that the cables themselves are copper cables and range in metric size from 0.5mm up to about 16mm (we do use up to 25mm in some assemblies).
    I am unsure if this would be an issue as I believe they would require a very strong magnet for a reaction?

    Is this a stupid idea that could not work or is there any mileage in it.
    I would love as much feed back as possible and any ideas would be very welcome.

    many thanks Max
  2. jcsd
  3. Dec 4, 2013 #2


    Staff: Mentor

    What would help is a photo or drawing of what you propose.

    I found these pictures of wiring harnesses and they all seem to be customized to the project at hand.


    Also, I found there were some patents of novel harnessing systems so its an area of active interest.
  4. Dec 4, 2013 #3
    Hi, yes some of the methods in these pictures we employ for mass production harnesses as we can easily absorb cost of jig cost and labour involved over many harnesses. However to keep cost down and speed up the process for prototypes and very low volumes we are looking to utilise the fullsize drawing we already create for the harness.
    The harnesses you see in the picture are made by jig makers and are then stored for use. The jigs we are looking to have will be used probably only once or they will have several changes until the product is finally released to production.
  5. Dec 4, 2013 #4

    Here is a sketch of what i had in mind. Its PDF.


    Attached Files:

  6. Dec 4, 2013 #5


    Staff: Mentor

    How about an electromagnetic chuck as the backboard plate:


    They seem kind of pricy at $14K for the largest one and not as big as you need it.

    The only other approach is to use a steel plate and make your pins using magnets strong enough to hold your wiring.
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