electromagnetic keyholder

Ideas and instructions how you can make your own bondage toys.
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locked_to_guitar
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Joined: 29 Aug 2013, 17:55

electromagnetic keyholder

Post by locked_to_guitar »

I've been playing around with the cd tray opener software and my laptop, it has been fun.

But i feel like it is rather difficult to set up my laptop in such a way that it will drop the keys in the right spot without me being able to get a hold of the rope they're hanging from. (since usually that rope is 4m long and i have to span it across the ceiling to make the setup work).

This leaves me unable to do anything with my laptop, and... i get bored :( and a little frustrated sometimes. So in order to fix that i figured, there must be a way to make this work without using my laptop or an ice lock (since i can never get those to work). So i figured, electromagnet would be the way to go. One i make myself from a nail and some insulated copper wire. Now, the problem i run into is my power source.

Because i'd like to use a wall outlet timer since they are reliable, but i'd have to use a transformer of some sorts, which will not only be expansive but also heavy and not very handy.

A second way would be to use a battery, this has the advantage of making it one package that i can then hang from the ceiling using some tape (no wires required, so impossible to get a hold of a wire and then pull it until you get free.) But, my sessions are usually relatively short, no more then an hour usually. So my question here would be: "How to make the timed release work?"

Or is there a secret 3e option that will make my keys inaccessible for anywhere from 20 min to an hour? (without the use of water)

I'd love to hear your thoughts, kind regards

Your guitar man.
lj
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Re: electromagnetic keyholder

Post by lj »

Can't see why you can't get an ice lock to work - there's not much to them !

But going to the electromagnet release.

You can of course make an electromagnet from wire wrapped round a nail, but you will need quite a lot of wire - magnet strength is proportional to the number of turns around the core and the current going through the wire. A home-made one would probably have quite a low resistance, which might be an advantage - you could connect a single cell - AA for example - which may well run down enough to release the key in the time-frame you are interested in. You.d need to experiment. The advantage of this method is you know it will release the key, though exactly when is a matter of chance. The disadvantage is you use a battery each time. You could, of course, use a rechargable battery, they are available in most sizes.

Bear in mind that an electromagnet retains some magnetism even when switched off, so use a piece of card or paper between magnet and key to ensure release - TEST before you click the locks!!!

Using a mains power supply is OK, and you can get the wall plug-in power units (phone chargers etc) very cheaply, but remember that you will then require a timer of some sort to switch it off. These power units aren't at all heavy, but you will have to match the current required by your magnet and the capacity of the power unit to supply it. Ideally you'd need a meter to measure the current, to make sure the supply was OK.

For what it is worth I always used an ice cube in a nylon mesh bag, the bag threaded through a chain link, so the ice had to melt before the bag could release through the chain link. A single cube would last around 40 minutes if I couldn't warm it with my hands, and of course you can use a bigger cube for a longer time.
be a switch, double the fun :-)
locked_to_guitar
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Re: electromagnetic keyholder

Post by locked_to_guitar »

I have a tendency to wrestle my restraints, and in the process destroy just about everything i can if it helps me get free.

So my policy is as follows: if its in reach, its fair game.

I can't see (maybe its because its late) how the stocking ice cube thing would work with a chain link or maybe i misunderstood.

The plan with the mains would be to use a timer like you can get in any store to turn the lights on an off when you're away (so people don't break in).

Good tip on the magnet not going completely blanko when the power is turned off. I guess weighing down my keys would also be a good plan, and the paper thing ofc.

Thanks a lot for the reply btw :)

If i wanted to do this with a store bought magnet, what would i need?
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Sir Cumference
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Re: electromagnetic keyholder

Post by Sir Cumference »

"What do I need?"

It depends on how you want to set up your system.
Any of these:
http://www.ebay.com/bhp/12vdc-electromagnet
Could solve the problem in one way or the other.


A timer, a 12V wall wart end the magnet is all you need.

I would use a magnetic key ring, place the magnet above me, and let the key drop when time was up.
To make sure it did not disappear after release, I would attach the key to a string (a relatively stiff one that would not get tangled when the key dropped) to make sure, that it would swing right into the perfect position where I needed it.
~ Leatherworking, blacksmithing , woodworking and programming are the most pervertable skills you can learn! ~
lj
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Location: East Anglia, UK

Re: electromagnetic keyholder

Post by lj »

just to explain my ice-release - I did post this in detail but it was ages ago and I don't have time to search all my posts!!!!

The materials needed :

a short length of chain, with links at least 1/2" long and 1/2" wide

another piece of chain or a metal ring about 1-2" diameter

a nylon mesh bag. The ones I used are supplied free with some washing-powder tablets, about 4" square, with about 1/4" mesh, with a short nylon cord drawstring.

ice cube/block (release time depends on size of block)

method:

put ice cube in bag

thread the drawstring through the last link in the chain, pulling all the bag through until the ice-cube is trapped against the chain link.

wrap, thread and loop the drawstring around the metal ring (easier than using a chain, but this will work as well) so there is no free end.

fix the first chain to whatever is your anchor point

lock your wrist cuff to the ring.

You should not be able to unravel the cord once your wrist is secured to the ring, make sure you loop the cord to prevent this.

Now you must wait until the ice cube is small enough to slip through the chain link - I found this was about 40 minutes if you are unable to reach the ice cube and warm it with your hands. You can reverse the arrangement and lock the ring to the anchor point and lock yourself to the chain. The nylon mesh is strong enough to be almost impossible to break with your bare hands, even if you can reach it. Actually, I suspect the same would be true of a release made from several layers of stockings - again if you can't actually touch the stocking to break it, simply pulling would require a lot of force. But the nylon bag is re-useable and with a bit of practice you can secure it to the ring without tight knots, just loops
be a switch, double the fun :-)
locked_to_guitar
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Re: electromagnetic keyholder

Post by locked_to_guitar »

That actually sounds like it might work =D thanks a lot!

And just to be sure, the amperage doesn't matter on my converter right? as long as its the same or higher then the magnets requirements?
locked_to_guitar
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Re: electromagnetic keyholder

Post by locked_to_guitar »

Bought the magnet just because aside from my bondage interests i think its cool :) i can get an adapter for 5 euro that gives me 12v dc and 300 mA, would that be enough? i think so right?
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