Recovering Nichrome Wire from Unexpected Sources

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Don’t you hate it when you’re in a pinch and all your favorite surplus or electronic stores are closed? You’ve gotta finish this project, but how? He’s a nice real hack for you guys.  How to recover nichrome wire from a ceramic heater!

Necessity spawned this idea, as [Armilar] needed to make 45 cuts in two pieces of foam in order to ship some long circuit boards. Not wanting to make the 90 cuts individually, he improvised this nichrome slicing jig. Not having a spool of nichrome handy, he decided to use a less conventional method. He pulled out a sledgehammer and smashed open a ceramic wirewound resistor.

According to him, nice big ceramic resistors like this 10W one have about a meter of nichrome wire inside!  After breaking the ceramic, it’s quite easy to remove. He made up a jig using nylon spacers and rivets, and then wrapped his wire back and forth across the whole length. It worked perfectly — though he was using 240VDC @ about 1.2A…

If you don’t need such a complex setup, there’s always the bare bones wire foam cutters we’ve featured many times before.

Comments

  1. the gambler says:

    nice but i’m curious as to why he had to have nichrome wire. I recently made a foam cutter for a friend and after way to much reading on making foamies realized that tiedown wire for airplanes, fishing leaders, and countless other around the house objects work just as well. Now if he didn’t have any alternatives that have proven themselves then i understand his smashing of the resistor.

    • tekkieneet says:

      Nichrome wire has higher resistance/length vs other types of wire. So you can use a lower current and higher voltage to achieve same heating effects. Lower current means that the rest of the non-resistive wire would have less losses and easier to find a source to power it.

      For a one time thing, use whatever you have one hand is the DIY way.

  2. Haasebert says:

    I scavenged my nichrome (maybe?) wire from a hair dryer that had stopped working. Lots and lots of length in 2 different diameters. It was all coiled up, but after pulling it across the edge of a wooden table a few times it straightened out enough to be usable.

    • nixieguy says:

      Never thought of that!
      That makes me think that in an industrial environment, you can probably get a broken heat gun to the same effect (altough power resistors will still be easier to find than a nonworking tool)

      • Haasebert says:

        True. But depending on the availability of nichrome in your area, the tools can sometimes be easier to find. And while I don’t generally like to break things that are working, you might be able to buy a super-cheap (functioning) hair dryer at your local big-box store (or order it online) for less than the cost of a spool of wire. I got my heat gun at Harbor Freight for $10, for reference. But that is still functioning as a heat gun, so I won’t be tearing into it anytime soon. The hair dryer was nice because one of the wires was really fine, which gives me a smaller kerf.

        • Rob says:

          get a used hairdryer for $3 or $4 or so at your local thrift shop/Goodwill/etc… they’re never lacking in cheap-@ss hairdryers, and beyond the nichrome you can also salvage the cord/GFCI outlet from the unit, so you really get your money’s worth (never mind the fan, a few diodes, a couple power resistors, some micaboard heatshielding, spare screws, and two or three switches in the same assembly… components are never soldered either, just wrapped around a rivet post before it gets compressed).

    • Sven says:

      One has to look out when doing that, if the wire has been too hot, it might be extremely brittle. Scavenging wire would probably work on a hair dryer or electric space heater, but probably not from a paint stripper or hot air soldering iron.

  3. Hirudinea says:

    That is one hot lap guitar! Anyway this might be a good idea for getting nichrome wire in the first place, good will or lawn sale items might be cheaper than nichrome.

  4. Dax says:

    Seriously though. Doing 90 cuts individually is probably going to be faster than rigging up this jig.

    Even if you take a minute to do every single cut, it’s still beating the time and effort you’ll spend on scratching your head and figuring out where to get the parts and how to put it together.

    If you just sat down and started working, you’d be done in 45 minutes or less, but most people just go “90 cuts! That’s a very large number – I’m not doing that!”

    • pcf11 says:

      What if they had to do the 90 cuts repeatedly?

    • nixieguy says:

      Sorry!, I didn’t mention that the cuts had to be done for, at least, 60 times (2 times 30 bars, wich where then separated through the center, per board carrier, for 3600 boards).
      (“at least”, because we don’t know yet if this will become a continued production, or just a one time packaging effort)
      Also, wire cutting leaves a thicker, more depth consistent cut, than doing it by hand (for so many boards) wich then makes life easier for the lateral connectors when sliding the board in and out. (plus the amplitude of the cut is somewhat controlable through wire temperature, wich is a bonus!)

    • chuck says:

      Yeah, but sitting down with a ruler and a razor knife won’t get you mentioned on HaD.

      He mentions needing the foam to ship boards to a client so I assume he’s anticipating using this again in the future. Otherwise. yeah- not an efficient plan.

    • Jon S. says:

      sometimes it is more entertaining to the ADD mind to figure out a way to avoid the same task 90x…

  5. thatguy says:

    Thin mig welding wire works very well for a hotwire foam cutter, and is easy to source at an average hardware store.

  6. Tim Kyle says:

    I always used whatever wire was on hand, a couple of 100w light bulbs for current limiting and a dimmer switch for control. Worked great.

    • Haasebert says:

      Interesting, but I don’t like having my hands near exposed wire with mains voltage running through it. Personal preference ;) I ended up using a LiPo battery, a brushed RC motor speed controller, a trim pot, and an Arduino for mine. I know it’s more complicated, but:
      1) it was made with things I just had laying around.
      2) the whole setup can attach to the bow so I have a super-portable cutter that can be used in the field with no access to mains power (great for RC airplane events).

  7. dave says:

    i’m more interested in those boards. looks like led’s on an aluminum substrate?

    • nixieguy says:

      Yes, they are. It’s more or less becoming the norm in all high power led lighting, it has it’s benefits and drawbacks. You can’t perfom repairs on the bare board with a normal soldering iron, because it radiates too much so you can’t get the component to temperature . On the other side, you can do emergency repairs with just a hot air gun, being careful with the distance.
      It has even been developed a special 1mm aluminium bendable board to conform to special shapes (still, you must be careful, as you can easily break the ceramic leds if you bend in the wrong point.)

  8. isaturnine says:

    Be careful if you take apart heating elements of unknown vintage, there might well be asbestos in there…

  9. Edward Lye says:

    My secret ingredient is guitar wire. I think it is a B-string.

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