Microwave Ovens Turn You into Spiderman

Want to climb a wall like Spiderman? No problem – just whip up a climbing rig with microwave oven transformers. And find a steel building. And rewrite the canon so that Peter Parker is bitten by an electromagnetic spider instead of a radioactive one.

Back in the reality-based world, you’d probably be taking you life in your hands if you use [Make It Extreme]’s rig to get more than a dozen feet above the ground. The basics are pretty sound, but the devil is in the details. Four MOTs are cut and stripped of their secondary coils and attached to fixtures for the feet and hands. A backpack full of gel cell batteries powers the rig, and simple normally closed switches in the handholds control both the foot and hand magnets on a side.  A click of a switch releases the magnets on one side, allowing the climber to reach up.

And therein lies our safety beef: what happens when you make a mistake and push both buttons at the same time? Seems like this build is screaming for some control circuitry that prevents this most obvious failure mode. We’re not ones to throw an Arduino at every problem, but in this case it may make sense, especially when it could monitor your time left before cratering the charge remaining in the battery pack.

Still, like most dangerous stunts, this looks really cool. If you’ve got any ideas for improvements in the controls, leave them in the comments below. And if you’re interested in transforming yourself into a superhero, learn from a guy who’s actually doing it – our own [James Hobson]. Check out some of his builds, like the Captain America shield or his car-lifting exoskeleton.

42 thoughts on “Microwave Ovens Turn You into Spiderman

  1. Or you know, just a double-pole, double-throw switch that cuts off one when turning on the other, controlling a pair of relays with a built-in delay to allow the de-energized side to hold while the energized side clamps down. At work, can’t watch the video – does the rig have the left foot and right hand on one circuit, with the left hand and right foot on the other? Would seem more natural than having the same side of the body energized or de-energized.

    1. But if you want to pause for breath, it would be nice to leave all circuits energized — you could use a 3-position SPDT and two relays with NC contacts, so the center position would leave both circuits on.

      Either way, I think the idea of one switch for each hand is to make it more intuitive in use, and any single-switch solution compromises that — for that reason, I’d keep the user interface it has now, and put the foolproofing interlock elsewhere. Mechanically interlocked relays are a thing (commonly used for reversing motors, to prevent shorting the supply), or you can wire it for an electrical interlock in a number of ways.

    2. Considering the “battery left” issue, would it be possible to use rare earth magnets to keep you attached to the building, then use electromagnets the counteract the permanent magnets for long enough the move that side? This way tyou have a “fail SAFE” system rather than a “fail SPLAT” one.

      I guess I would be worried that the electromagnet would weaken the permanent magnet’s strength over time. Not sure if that worry is justified or not.

      1. I think that’s a great idea and would definitely help the “operating time” and the life expectancy of the batteries. You could use the electromagnet to detach the magnet so you avoid having current running all the time. Good stuff.

    3. In the blog entry (first link in the piece) he says that he first tried the “right hand, left foot” switching arrangement but found it difficult to coordinate his climb. He said same-side switching felt more natural.

  2. Or maybe you could have insane regenerative abilities and blades come out your knuckles and you’d be like the invisible man, because if a limb was poking out from were you were trying to hide you could cut it off…

    … just like having add on MAGNETic abilities makes yOu spiderman.

  3. That looks like an excellent electromagnet! I’m not climbing any walls, just picking up ferrous metals off of the floor/ground.

    Don’t forget the smaller magnet inside the magnetron, though it is difficult and dangerous to remove; very sharp metal.

          1. They almost always have a warning label near the magnetron itself. If you crack or crush it the dust is toxic and probably get lung disease.

            There are almost always in x-ray machines and sometimes are in commercial-scale microwaves. I personally wouldn’t crack one open if I saw a Beryllium label.

  4. Double pole, double throw switches would add safety. When one side is de-energized the other gets juice whether they disengage power or not.

    Agree about left hand, right foot and vice versa. Would seem to be a more natural climb.

    Do you think a linkage akin to those used in rock climbing walls while they were ascending would have been sensible.??

    Neat though.

      1. Yup, you’re right. Missed that.

        We’ve got a device here at our plant (thankfully no longer in use) that suffered from a problem because it was make before break and would send a voltage into a circuit not able to handle the 48V. First words out of my mouth “did the manufacturer not put in ‘break before make’ switches?”

    1. A rock climber always maintains three points of contact. By that philosophy, perhaps this system’s safety interlock should only allow one of the four magnets to release at a time. Another possible safety measure would be to isolate each coil to a dedicated battery.

      The safety interlock circuit should allow a coil to release only if the remaining coils are drawing enough to indicate they’re locked on a ferrous surface. And a manual switch could provide an interlock override to allow you to climb down in case the overly complex safety circuit fails.

      1. The current drawn is independent of the surface under the coil. It depends only on battery voltage and coil resistance. You could superimpose a small AC signal to measure inductance, which is dependent of the magnetic circuit.

  5. I’d be worried about delay in the magnetezation with a DPDT switch. You really want to have everything energized for a bit before you allow either side to release. Otherwise you’ll suddenly be changing your stance from one side to another, it might just rip the magnet off the wall. I think a few DPDT relays arranged in an odd cross interlock arrangement (denergize A closes contact around B and vice versa) would be the simplest method, but still doesn’t give it any time to grab.

    One neat trick I’ve seen industrially is done by ABB Magne line of solid state magnetic door locks. They do something like check the current draw on the coil (not sure the methodology) but they automatically detect if there is steel in front of them and will only turn on fully if there is. They also provide a feedback signal to tell you they attached successfully. Something like that and a little more overlap control would make this slightly less death defying.

    1. You might want to mention that Colin burned off the skin on a good portion of his arms playing around with a “Turbo Grill” if I remember correctly. He’s a bit crazy, brilliant I think, but crazy. That being said – I want his 70 mile an hour handicap chair.

  6. Myth Busters did a bit on something like this during their “Breaking into a secured facility” video. There are defiantly issues with electromagnets and climbing surfaces.

  7. Personally if I was going to do that I’d be using flux redirection of some really large neodymium magnets.
    Less continuous power is required. Granted a slightly more technical build to get it balanced but probably the better option.

  8. I’m thinking there should be a load sensor on each electromagnet, and a control system that won’t disengage a magnet until the load is removed. This should prevent several nasty failure modes. Magnet on isn’t a sufficient indicator of magnet attached. Electro-permanent magnets also make sense for fail-safe.

  9. I noticed each module had a fuse on the wiring just before the transformer halves. Wouldn’t that be an unnecessary and potentially dangerous fail point? A little extra juice to a transformer seems less hazardous than a fuse blowing and leaving you with dead weight on one limb.

    1. Yes, I would prefer temperature sensors in the coils – to indicate, not break a circuit – in this case. “Power off” is not the safe state in this kind of technology. Similar to airplane technology.

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