DIY electronic selfbondage cuffs

[Like Ra]

Following my fiasco with the electromagnetic cuffs last summer (they broke after the first serious use), I started collecting various ideas about making a DIY version.

First of all, have a look at this post:

Electronic bondage, magnets, and mathematics

I (independently) came up with the same idea. Instead of using long cables (which can be disconnected or broken), you can use a local rechargeable battery. The more hours you are going to stay in bondage, the more powerful the battery should be. That means - no time-relays or mechanisms. All you need is a 9V battery and an electromagnet.

So, the basic design is quite simple:

o- handcuffs
o- electromagnet
o- 9v battery
o- metal piece/plate for the second cuff
o- battery case
o- battery connector
o- bolts
o- washers

Electromagnets you can get on eBay:

eBay: holding (electro magnet,electromagnet)
Search eBay UK: holding (electro magnet,electromagnet)

How big should it be? What I could find on eBay is too thick (2cm+).

The metal piece for the second part (any good names for this one?) should look like a cup, so the magnet can easily fit inside. This is to prevent sliding the magnet off the 2nd piece. Also this design will allow to use less strong magnet or less powerful battery.

The batteries. This is easy:

eBay: 9v rechargeable battery
Search eBay UK: 9v rechargeable battery

As you can see, you can find various models: LiIon, NiMH, 250mAh, 300mAh, 600mAh, 680mAH, 780mAh, 880mAh... Pick up several and do not forget a charger:

Connector. Also easy:

eBay: 9v battery connector
Search eBay UK: 9v battery connector

Now comes a more difficult to find "ingredient". The case or holder. I could not find anything rigid and reliable on eBay:

">eBay: "9v battery" (holder,case)
Search eBay UK: "9v battery" (holder,case)

Any ideas?

Cuffs. There are so many to choose from...

eBay: leather lockable wrist cuffs
Search eBay UK: leather lockable wrist cuffs

But I have no idea where to get the metal part that will be hold by the magnet ...


Related threads:

Battery powered electromagnetic lock with additional safety mechanisms
Arduino controllers and self-bondage designs

[Like Ra]

Another possibility is to use a thick wide belt with two attached magnets (behind the back, ~10cm from each other) and two batteries. The wrist cuffs will have only the metal disks/cups.

[Tinker D]

In arcade games, pinballs, cranes, we use solanoids. They have two parts. The coil and the plunger. The plunger can have a steel ring on it, and the coil, located in a steel housing, can also have a ring.

However, the wires are still a problem.

The coil can be engergised and as soon as you place the plunger in the coil, it locks untill the battery weakens or the wires are cut.

The wires can fit in a flexible steel tube to the battery.

Thinking about this, the solanoid and plunger looks a lot like an ice lock.

[Tinker D]

Battery holder?
Take your 9 volt battery, and Ducktape it to the solanoid.
That should keep it in place.

I think I have a solanoid around here somewhere.

[Like Ra]

Take your 9 volt battery, and Ducktape it to the solanoid.

I thought about it. The easiest and the most reliable way, however not flexible enough in terms of battery replacement or connecting the battery at the right moment.

[Tinker D]

True, but once the battery connector is connected to the coil, the coil is now on. And, once you slide the plunger into the coil, it will lock in and stay locked till the battery goes dead. Then the plunger will be free and so will you.

[Tinker D]

Oh, almost forgot, not all solanoids are round. Some have a square frame that a battery clip can be bolted on.
That would solved the Ducktape.

[Like Ra]

True, but once the battery connector is connected to the coil, the coil is now on.

If the connector can easily be connected, it can easily be disconnected, right? Unless heavily taped shut.

Also, my idea is not to use a solenoid and a plunger, but a complete electromagnet with a metal plate.

Some have a square frame

Square one are not good for fiddling behind your back 😉 Plus it might have sharp edges.

[Tinker D]

True. I was thinking about something like the ice lock.

[Like Ra]

Any ideas where to get suitable round plates?