MakeShift Challenge: Retrieve Your Keys from a 15′ Crevice: Honorable Mention

Ray Gibson’s Honorable Mention Entry
by Lee D. Zlotoff
September 25, 2007

“Is something wrong, Honey?”

Seriously! Stranded in the middle of the Mojave Desert? Maybe not. There are many ways to proceed but only a couple worth looking at considering the time available. Obviously, trying to move the boulders providing the shelter for my keys would be a bad idea. Even if I constructed a lever large enough to move them, I am endangering myself, my mate, and the future of my keys. I somehow need to lift them out of there, and the only logical solution to do so would be to use something magnetized to lift them out.

You see, I keep a strong neodymium magnet in my car for this very reason. Unfortunately, we’re in my mate’s SUV and she’s not as much into this stuff as I am. My first thought is to make an electromagnet with some wire and my car’s battery. Where can I get some wire? I was just crawling through some barbed wire, but it’s not insulated and would make a poor coil, not to mention giving me a reason to go get a tetanus shot when I finally get home. My eyes turn to the metal detector… There’s got to be a coil in there, right? I grab the screwdriver from the tool kit and take off the bottom plate of the metal detector. I find a coil of wire! It looks to be about 300 turns of 25 AWG magnet wire around a hollow core. Perfect! I turn to my girl and say “Honey, I’m really sorry, but I need the wire out of this metal detector to get us out of here.” She looks back at me and says “Honey, if this doesn’t work, I’m not going to kiss you for a month.” Great, what perfect motivation. I think the whole world is out to get me sometimes.

If I’m going to make my electromagnet work, I need an iron core. Looking around my tool set, I see my screwdriver, wrench, and pick axe, which at this point I would rather keep intact in case I need them. I send my honey to go find some short pieces of metal, as we’re in an old mining area. I ask her to find something between the size of a railroad tie and a large nail. I spend the time removing the coil from the metal detector. I take a drink of water and think to myself, “dang, this had better work.”

About ten minutes later, my girl comes back with two handfuls of wonderful options, including two railroad ties and some re-bar. Comparing my wire to the ties, I realize I don’t have enough wire and I settle on the five inch piece of re-bar. Diligently, I wrap all of the wire from the removed metal detector coil around this piece of re-bar. While I’m doing this daunting task, I remember back to physics class and seeing my professor hit an iron rod with a hammer while pointed north. It was something about aligning the particles in the iron parallel with the earth’s magnetic field… Oh well, I don’t have a compass but I think I know where north is. As I finish wrapping the magnet wire around the re-bar, I smile knowing that I have a backup plan in case this fails.

I decide to test my magnet. I pop the hood of the car and carefully connect one lead of wire to the negative terminal of my car’s battery. I then carefully touch the other wire lead to the positive terminal. Suddenly, I realize what “50 cranking amp power” means for real as sparks fly and the re-bar heats up so much that i have to drop it almost immediately after I connect the lead to the terminal.


If I am going to make the electromagnet work with the car battery, I need a lot more thicker wire and a larger core. My mind wanders to the barbed wire fence and then I come up with another brilliant idea. I take my cell phone out of my pocket and pop the battery off. I read ” 3.7V Li-ion.” Perfect. This battery should have just enough juice to power my magnet without overheating, and is small enough to fit in the crevice where my keys are! Using my snippers I am able to pry the leads on my cell phone’s battery up just enough that I can wrap the magnet wire around them. I test my new electromagnet and find that it picks up other little pieces of iron just fine. Now, I just need a way to lower this into the crevice and not lose it!

I find a small piece of wood lying around, about 8 inches long and one inch wide and deep. Using the snippers I cut a couple small pieces of nylon rope and secure the electromagent parts to the piece of wood. The best knot to use for this is a constrictor, while similar to a clove hitch, is better for this situation because it ties very tight and is difficult to untie. With the remaining nylon rope I tie a timber hitch to my apparatus, which I am effectively able to lower into the hole, and after a few minutes of fishing, hear the clanking of my keys attached to my drempt up magnet. I slowly raise the rope and successfully recover my keys. Once they are safely in my hand and my mate and I are a succifient distance away from the original hole, she gives me a long, passionate kiss. We return all our tools and broken metal detector to the car and drive home, stopping for Chinese take-out on the way.

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