[Peter] And The Amazing Technicolor Phone Wire Bracelet

When a job left him with some extra phone wire, [Peter] didn’t toss it in the scrap pile. He broke out the casting resin and made an awesome bracelet (Imgur link). [Peter] is becoming quite an accomplished jeweler! When we last checked in on him, he was making rings out of colored pencils.

Casting the wire in resin was as simple as building a square form, placing the wires, then filling the form with appropriate amounts of epoxy and hardener. Once the epoxy cured, [Peter] drilled out the center with a sharp Forstner bit. A band saw brought the corners of the block closer to a cylinder.

From there it was over to the lathe, where [Peter] used a jam chuck to hold the bracelet in place. Once he shaped the bracelet [Peter] started wet sanding. It took Lots and lots of sanding both inside and out to finish the bracelet. The result is a mirror smooth finish, with bits of insulation bright copper just popping out of the resin.

One might think that the bracelet would be rough with all that copper, but [Peter] mentions on his Reddit Thread that it feels like plastic, though the bits of copper were “very pokey” before sanding. We’d recommend tossing on a clear coating to protect the exposed copper. Worn on a wrist, all that exposed metal would start oxidizing in no time.

This hack gives us lots of ideas for casting wearable circuits. Some WS2812’s and a teensy would make for a pretty flashy setup! Got an idea for a project? Tell us about in the comments, or post it up on Hackaday.io!

31 thoughts on “[Peter] And The Amazing Technicolor Phone Wire Bracelet

        1. Thank you for that. A constructive criticism of the project that informed me of a risk I wasn’t aware of. I’ve been using epoxy resins for something like 40 years or so and I never knew they had BPA in them or that in the cured form that they could cause skin reactions. I’ve never experienced any issues with cured epoxy, but it’s good to know. Without your post I may have tried something like this someday.

          If anyone has a source for a multipart resin without BPA please post it.

          1. Silicone resins (platinum cured) can be fairly high in durometer and quite skin safe but they will not be anywhere near as hard. Some cured urethanes are probably a better alternative than epoxy and there’s also acrylics, which are castable, low cost and optically clear when cast under pressure or thoroughly degassed. Glass would probably be the most inert but it would melt the insulation and possibly the copper too when working with it and a glass ring sounds like a bad idea from a safety perspective, even if it was borosilicate glass (better known as Pyrex in the US). The issue with BPA isn’t that it’s going to irritate the skin like nickel does for some people (skin reactions), it’s the hormonal like properties that are of concern.

            Not trying to rain on your parade too much as it’s encapsulated in this application but the PVC insulation on the wires contains phthalates. http://en.wikipedia.org/wiki/Phthalate Aside from being another concerning chemical, it tends to inhibit silicone resin curing. That’s why you don’t use vinyl gloves when working with silicones.

            It’s a very pretty ring though!

  1. Oh my, I just watched the video!

    At 1:21 he’s drilling in a completely unsafe way. If that bit catches, he’s about 1 millisecond from completely ripping his abdomen apart. I actually looked away for a moment.

    I’m generally not a safety nanny, but that scared the bees out of me.

    1. And if you look really closely while he’s drilling, you’ll actually see the drill chuck stall several times. This means that the holding force he’s exerting is easily sufficient to overcome the maximum torque that the drill press can exert – remember they are belt-driven and can slip, especially if it’s an older model. So there is no risk of the drill grabbing the workpiece.

      Yes, I know, it doesn’t appear a safe method and obviously shouldn’t be done if you have a much more powerful drill press. But if you are aware of your drill’s capabilities, then there is really no reason not to do it this way.

      The drill press I have has a relatively loose belt, and I can easily hold the chuck when running – e.g. if a drill binds in material, or breaks through the back of a sheet and catches. It’s far safer this way, than having a tight drive which tries to keep turning the drill even when it’s stuck.

      1. When I viewed the video I noticed that also, but I it’s an effect of the time-lapse nature of the video. But it’s 100% possible I’m misinterpreting the video.

        I do like the idea of letting the belts slip to provide a “limited torque” drill. Is there a commercial stepped pulley that has a limited torque setting? That seems like a really useful thing to have on a drill press.

        I know my metal lathe had a multipart pulley that used hardened steel balls and springs to provide a limited torque capability. And it was REALLY noisy and scary when it let loose. Like a machine gun going off. So you pretty much tried like all heck to not trigger it.

      2. Lindsay Wilson says:
        “But if you are aware of your drill’s capabilities, then there is really no reason not to do it this way.”

        I don’t agree with this statement. There is a reason not to do it this way, the risk of getting gutted.

        We may choose different level of risk for ourselves, but saying there’s NO reason not to do it this way I can’t agree with.

    2. You are correct, that does look unsafe. The truth is that 15 seconds was about a 10 minute ordeal. And my little Drill press was stalling out a lot. Lucky it was a freshly sharpened bit or I don’t think it would have worked at all! But regardless, I should have clamped it…

      1. Nicely done by the way. I’m glad you’re safe and I hope you send in links to other projects. This one looks very pretty.I’d like to try using a bunch of old ICs, resistors and other junk, but use it as an art object and not a wearable. I’ll post something if I ever get around to it.

  2. A Teensy would be overkill. You could just use an ATTiny45 or -85 to drive WS2812s. With a little planning, you could probably embed some rechargable batteries and expose leads that would allow charging and reprogramming. Heck, might as well throw in an accelerometer, so it can trigger light patterns based on movement.

    As far as the BPA issue goes, there are other clear casting materials, or maybe you could just use some spray sealant?

      1. I wonder if you could use the inductive coil as a RF sensor, so the ring would light up to ambient RF fields. I get the feeling that it would be less of a ring and more of a bracelet at that point however…

  3. Just try to look at it as an impromptu fabrication lesson guys.
    Yes I took my turn at a curmudgeonly shot at the drill press methodology.
    But overall does this not beat a dry reading of the instructions on the packages of materials?
    You guys put up some thoughts and links about the various chemicals and a few folks seemed grateful for that.
    We got a non critical run through on a way to perhaps build an (embelished) enclosure or embed some circuitry.
    Maybe you’re building a nice amp to play those S###y sounding mp3s through and would like something a bit non-standard for the control knobs?
    Sometimes a non-fail of the week item is a fine teaching tool also.

  4. I’ve never done anything like this so maybe I’m talking rot, but:

    Would it not have been easier to have some kind of tube in the centre of the form with the wires wrapped loosely around, then he would have saved some resin and not had to cut out a bleedin’ great hole? :)

    1. Exactly, it reminds me of the cave man carving a wheel out of a square rock instead of just looking for a rounded rock to start with. Maybe he was thinking it would add to the random-ness of the wires.

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