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Can I make a portable electromagnet that will support my body weight? Answered

I would like to make a couple of electromagnets that will support my body weight, I'm about 75kg, the idea is climbing along underneath bridges ;) Is it possible? What sort of batteries would I need? I hope you can get what I mean. Thanks Jamie


i know that there are door closer magnets (that hold doors closed simply with their strength) and you need to ride into the door with a manual forklift to open they seem strong enough but i have no clue whether they work on 12 V or mains power and how much power they take the batteries you need are probably sealed lead acid. deep cycle batteries preferred anyway be ready that there is no warning before power goes out the magnets and batteries are not reliable enough to trust your life on them. if you cant allow yourself to fall into the water then you need a rope and clip backup (that oyu use all the time) or at the very least fully independant double magnets / batteries and a circuit that senses and warns when one of them is not ok / when batteries are going to die

yes you could but you wouldn't be able to walk upside down or sideways due to the weight of what you would carry unless your electromagnets are bigger than you

Electromagnets are not the only way to turn a magnetic force on and off. While personally I would rather not be hanging off a bridge by anything, I would put greater trust in a permanent magnet.

There are devices designed for lifting heavy metal objects that incorporate a permanent magnet, focusing plates, and a lever mechanism. Two of these might do the trick.

Problem with a permanent magnet that will hold 75 kg is that it's gunna take like 100 kg of force to take off-thus an electromagnet. Could you? Yes, but it's going to take a car battery and not last long and weigh a ton and give way at the worst time. Magnetic strength is related to amps and number of coils and what is inside the coil.

The permanent magnet device uses a lever to remove the magnet from the surface- less force traded for more distance. If you securely clipped yourself to the bridge with ropes during each removal, it seems fairly safe (as much as dangling from a bridge is going to get.) I'm not sure what to think of the "easy to use" claim, but even the one with a breakaway force of 13,200 lbs says that it can be operated by hand. The only catch I see is that the rating assumes that the surface contains sufficient magnetic material to contain the magnetic field.

I can operate a mechanical jack 'by hand', but there's no way I'm going to be able to do it while hanging under a bridge : ) "LIGHT: Detachment strength from 80 to 115 times its weight" and "Maximum breakaway force: 3960 lbs. (3X)" and " it can be incorporated in any type of crane" says to me that it weighs 30 some pounds. Then again, most of my comments on things like this are to say that, yes it's technicaly possible but that the practical aspects make it very difficult so don't risk you life trying something that probably won't work. (You can blame my inner-parent)

Very true, jtobako. This is not something you'd want to do without extensive rock climbing experience and the supervision of someone who climbs bridges professionally.

im not sure if you get what nobodyinparticular said... there are ways of getting the magnet off of a metallic surface, with just brute force

Are they ones you would trust your life with? (I've used some of them, fine for picking up and dropping nails, not for sticking to, say, refrigerators) Have you tried them? PITA if you ask me : )