Holding force for electro magnet in selfbondage

Sometimes you just have to do things yourself.
selfboundslave
Unfettered Newbie
Posts: 29
Joined: 15 Nov 2012, 18:19

Holding force for electro magnet in selfbondage

Unread post by selfboundslave »

I'm looking into using electro magnets with a timer for use in selfbondage. They'll mostly be used in a tight spreadeagle to secure the ropes going to the cuffs around my wrists. I'm not sure what kind of holding force the electro magnets should have as a minimum. Would 60 kg be enough that I can't break free early? I'm a skinny guy and not particularly muscular, and as I'll be in a tight spreadeagle, I don't think I'll be able to pull all that hard. Anybody have any experience with this?

User avatar
twistedkinking
Unfettered Newbie
Posts: 12
Joined: 20 Jun 2015, 22:15
Location: Canada

Re: Holding force for electro magnet in selfbondage

Unread post by twistedkinking »

Hello selfboundslave,

This really depends on how you use them. The holding force is specified perpendicular to the magnet. Unfortunately, when pulling the magnet at a small angle will cause the armature plate to slide accross the face of the magnet until the holding force drops significantly enough for the plate to break free. And it doesn't take much of an angle or much force to achieve this. Essentially, if you do a spread-eagle with your wrists directly locked to the armature plate which are then locked to the magnet, a 60kg magnet will definetely not work and, depending on the setup, a 120kg magnet might not either.

However, lets suppose a different setup. Attach a length of rope/chain to your wrist cuffs, have that rope/chain run through an O-ring fixed to the bed, then have the rope/chain run to the maglock. This will do two things. For one, this will increase friction on the line, thus artificially increasing the holding force of the magnet. Second, this will ensure the pull applied to the magnet remains perpendicular to the armature/magnet interface thus ensure the magnet will not slide off depending on how you struggle. Whatever you do, make sure you can't touch the magnet or pull it at an angle as you will be able to slide it off, regardless of the holding force.

We have a similar setup to the one described here and we use 60kg magnet locks. If done right, there's no escaping.

Also, if using a timer, I recommend you use two, one plugged into the other. That way if one fails the other will cut-off anyway. Besides, they're really cheap, in every sense of the word.

Here is a link one of my previous posts on the setup I'm refering to:
http://boundforum.com/viewtopic.php?f=11&t=102380

And here are links to the project itself: When you get your solution working, post a few pictures/descriptions of it! It might inspire some good ideas.

justDIY
Tightly Hogtied
Posts: 245
Joined: 17 Nov 2007, 00:47
Location: United States

Re: Holding force for electro magnet in selfbondage

Unread post by justDIY »

fantastic website twistedkinking - i like that style!

Good points about the door-holder magnets being weak when it comes to off-axis forces. I've found for the round ones, putting the electromagnet inside a piece of PVC plumbing works great... Just a 1/4" deep or so "lip" stops you from sliding the armature plate in any direction. For the stronger rectangular magnets, building a wood box around the magnet works.

Twisted mentions it on the website, but I'll repeat here - its always a good idea to use two or more timers when working with electromagnets. I use two of those wind-up type timers like you would use for a vent fan or spa pump, up to 4 hours (other times are also available). The two timers fit nicely in a junction box, and are wired into an extension cord I cut in half.

selfboundslave
Unfettered Newbie
Posts: 29
Joined: 15 Nov 2012, 18:19

Re: Holding force for electro magnet in selfbondage

Unread post by selfboundslave »

Thanks for the feedback! My plan is to have the magnet (or magnets if I get two) attached to the legs of the bed, with rope running from the magnets under the bed, around the leg on the opposite side and up over the bed to my wrist cuffs. That should ensure a straight pull on the magnet so it doesn't slide off. I found some magnets with 180 kg of holding force for $26, so I think I'll be getting one or two of those. Then a 220 to 12 volt adapter and a couple of electrical timers. I'm also considering getting an outlet plug that can be switched on and off via USB cable to my computer. Meaning that someone else can control when I'll be set free by using Teamviewer and a webcam to control my computer remotely (and with an electrical timer as backup).

justDIY
Tightly Hogtied
Posts: 245
Joined: 17 Nov 2007, 00:47
Location: United States

Re: Holding force for electro magnet in selfbondage

Unread post by justDIY »

sounds like fun! please post an updates on your endeavors...

selfboundslave
Unfettered Newbie
Posts: 29
Joined: 15 Nov 2012, 18:19

Re: Holding force for electro magnet in selfbondage

Unread post by selfboundslave »

Will do. So far I've ordered 1 electro magnet with a holding force of 180 kg. Should arrive in a couple of days. Then need to buy the other stuff locally. If it all works out, I'll probably be ordering a second magnet.

selfboundslave
Unfettered Newbie
Posts: 29
Joined: 15 Nov 2012, 18:19

Re: Holding force for electro magnet in selfbondage

Unread post by selfboundslave »

Well that worked pretty much perfectly!

Here's a pic of the electro magnet:

Image

I had to remove some covers at each end of the magnet to be able to thread my rope through the holes. The loop on the magnet goes around a leg of my bed, then the metal plate is attached (I bought the hook and spacers separately) and the rope attached to the hook runs under the bed an up and around the leg on the opposite side, where a special ring device is attached so I can tighten it (all four attachment points are tightened with a SRD). The result is a very tight spreadeagle. I just did a 25 minute test session (only other gear was my buttplug) and it worked flawlessly. There's no way in hell I can pull the plate off the magnet when it's on, and the timers worked perfectly (one digital timer with a countdown setting and one mechanical timer for backup). It feels so much better being tied down tight when I don't have to worry about my hands going numb because I need to be able to cut the rope with a pair of scissors... or worry about water spilling onto the floor from melting ice. I bought one of those Ice Warden selfbondage locks some time ago and didn't like it for two reasons: it only lasted about 20-25 minutes (even though I'd wrap it in an insulating material) and it would loosen a bit before completely freeing me. What I love about the magnet is that there's no chance of escape before it switches off.

Will probably do a "real" session tomorrow with my latex mask, inflatable gag and blindfold as well as my electro prostate stim w/ vibration and penis stim all held securely in place under my latex briefs. Can't wait! :D

justDIY
Tightly Hogtied
Posts: 245
Joined: 17 Nov 2007, 00:47
Location: United States

Re: Holding force for electro magnet in selfbondage

Unread post by justDIY »

What do you (and others) use for emergency release while using a magnetic restraint?

My magnetic restraints hold my arms apart over my head while seated in my bondage chair, using heavy locking leather cuffs and chains. My sessions are all short less than an hour, mostly due to lack of a quick release system. I use redundant timers but that's it.

I'm thinking of two types of panic release... The first would be a string to a gallon pail of oil or oil paint sitting on a shelf. The pail would also have a string to the electrical cord for the magnets. Pulling the pail off the shelf would make a huge mess and unplug the magnets.

The other could be a panic button for a latching relay. The relay would cut power to the magnets and also power up a shredder, which has a sheet with several $100 bills taped to it.

Ideas?

selfboundslave
Unfettered Newbie
Posts: 29
Joined: 15 Nov 2012, 18:19

Re: Holding force for electro magnet in selfbondage

Unread post by selfboundslave »

For my 25 minute test session, I actually had a pair of scissors attached to my right wrist cuff via a rope. So I could at any time pull the scissors up to me and cut the rope. This was just because it was a test session and I'd never done that setup with magnets before. In the future, I'll probably either not have a panic release (and just have the double timers), or use the scissors connected via a rope, but also connected to a bucket of water that'll spill over my delicate wooden floor.

Also, I didn't get to do my full session yesterday, as I've suddenly got swamped in work. Typical. :/

User avatar
twistedkinking
Unfettered Newbie
Posts: 12
Joined: 20 Jun 2015, 22:15
Location: Canada

Re: Holding force for electro magnet in selfbondage

Unread post by twistedkinking »

Hello justDIY,

I strongly encourage that you do use a backup release. The great part of using electromagnets is that they can provide for near immediate release, so why not take advantage of that. The following circuit is what I use to control a pump located in one large bowl with a nozzle leading to another, where my cellphone is. Turning the pump on will submerge my cellphone in seconds. In order to control the pump, I use a small (and cheap) 12V relay.

The following image will give you a better idea of how this works:
Image

The relay is self energized, along with the magnets. This means that disconnecting the magnets will cause the relay to permanently de-energize, which will turn the pump on and destroy the whatever is in the second bowl. For a clean setup, you can use small switches through which the power to the magnets will be routed. For a quick and dirty setup, don't use switches. Instead, cut the wire where the switches would be, strip the ends of the wire and twist them together. Pulling on the wire hard enough will pull the twisted strands appart, thus breaking the circuit, de-energizing the relay and turning on the pump.

When it comes to your shredder idea, the same could be applied. All you have to do is find a shredder that will run on 12V or that you can adapt so that it runs on 12V. From there, simply place your "expensive" sheet of paper in the opening. Should you release yourself, the relay will de-energize, power the shredder and destroy whatever was in it.

I hope this is clear. Unfortunately, it's not always easy to explain these things. If you want more details, you can follow the links in my first response which will show more pictures and give a more complete explanation of this release mechanism.

selfboundslave
Unfettered Newbie
Posts: 29
Joined: 15 Nov 2012, 18:19

Re: Holding force for electro magnet in selfbondage

Unread post by selfboundslave »

Finally got around to recording a proper session with a strict spreadeagle and multiple forced anal/prostate orgasms over 50 minutes:

http://www.xtube.com/watch.php?v=fd76X-S805-

justDIY
Tightly Hogtied
Posts: 245
Joined: 17 Nov 2007, 00:47
Location: United States

Re: Holding force for electro magnet in selfbondage

Unread post by justDIY »

selfboundslave wrote:Finally got around to recording a proper session with a strict spreadeagle and multiple forced anal/prostate orgasms over 50 minutes:

http://www.xtube.com/watch.php?v=fd76X-S805-

fantastic! those estim were really hammering on you at times. does the intensity ramp up as the session goes on, or are the effects more random?

looks like a great ride. have you ever been tempted at the end to just reset the timer and go again?

selfboundslave
Unfettered Newbie
Posts: 29
Joined: 15 Nov 2012, 18:19

Re: Holding force for electro magnet in selfbondage

Unread post by selfboundslave »

The effects are more random. I've got 7 waveforms of about 2 minutes each. The computer chooses a random one to play whenever the current one ends, and then also randomly turns the volume up and down as it plays. I should've rotated the estim box a bit more towards the camera so you would've been able to see the intensity going up and down.

And, yeah, I've definitely been tempted to reset the timer, but I'm also pretty exhausted when it's over. You can hear me whimpering a bit towards the end as I'm forced into my prostate orgasm number I've-lost-count-at-this-point. I think I'd be more inclined to do another kind of session right after, perhaps one angled more towards torture than orgasms. Like turning over onto my back, putting in my XXL electro anal plug, clamps on my nipples and some loop electrodes around my cockhead and be forced to endure intense stim for 20 minutes.

justDIY
Tightly Hogtied
Posts: 245
Joined: 17 Nov 2007, 00:47
Location: United States

Re: Holding force for electro magnet in selfbondage

Unread post by justDIY »

Does either stim box respond to sound? That nice long breathing tube you have would really work against you placed close to a sound activated stim :twisted:

selfboundslave
Unfettered Newbie
Posts: 29
Joined: 15 Nov 2012, 18:19

Re: Holding force for electro magnet in selfbondage

Unread post by selfboundslave »

One of them does. That's how my computer controls the intensity of the stim on my dick -- by playing wave files and turning the volume up or down. The box (an ABox from E-Stim Systems) is just hooked up to the headphone port of my computer. It does also have a setting to take input through a built-in microphone, but I don't use that much, as the sound input has to be quite precise to give a good stim result (I have to finetune the computer's volume before each session).

Post Reply