Electromagnet cuffs

[ltxrob]

Started working on some elcmectromagnetic handcuffs 
Got 2 x 40mm 25kg rated 12v emags 
I plan to run these from 9v pp3 batteries 
Bolt the magnets onto the side of a box that will house the battery holders that I’ll 3D print. 
I did a quick test at 12v and 9v for strength and found that if pulled straight there wasn’t much difference but if slid then definitely yes. 
I’ll mount the magnets down in some pipe caps or other plumbing stuff that fits so they can only be pulled out straight. 
Will test with a dummy load to see what the time delay is for the 9v battery to
Run out. But calculations says it’s about 30-45mins depending on exact battery mah. That’s pretty much consistent with the YouTube vids from the company promoting products for sale. 
I should be able to combine it with the self bondage straight jacket that I got from bondage webbing a few years ago to hold things in place. 

Updates to follow.

[madjack]

Started working on some el Trina gets cuffs 
Got 2 x 40mm 25kg rated 12v emags 
I plan to run these from 9v pp3 batteries 
Bolt the magnets onto the side of a box that will house the battery holders that I’ll 3D print. 
I did a quick test at 12v and 9v for strength and found that if pulled straight there wasn’t much difference but if slid then definitely yes. 
I’ll mount the magnets down in some pipe caps or other plumbing stuff that fits so they can only be pulled out straight. 
Will test with a dummy load to see what the time delay is for the 9v battery to
Run out. But calculations says it’s about 30-45mins depending on exact battery mah. That’s pretty much consistent with the YouTube vids from the company promoting products for sale. 
I should be able to combine it with the self bondage straight jacket that I got from bondage webbing a few years ago to hold things in place. 

Updates to follow.

Random question about batteries...

If you are to believe the advertising and some consumer research then the life of a battery can be vary significantly between 'cheaper' and more expensive brands (we've all seen that Bunny - he just keeps going.....). Also I assume that powering a magnet will be a significant drain on any battery.


So: does the 30-45mins reflect the difference between worst and best battery types or is there another variable that needs to be factored in?


My experiences (non-kinky/non-sexy) of 9v PP3 batteries is as follows:

- rechargeable batteries are generally the least long lasting for any application (and I've seen little difference between brands for 200 and 300 mAH). I stopped using them as I found them to be more trouble than they were worth.

- cheapest batteries (e.g. bargain shop purchases) very variable with some lasting a few minutes but others almost as long as the better quality. For this reason I stopped using them in vital applications (smoke alarms). They all seemed particularly poor performers in high power drain applications. Having said that they seemed ok in remote controls, so long as you had a spare to hand when they suddenly died on you.

- medium priced batteries (recognised brands) some where rubbish, others quite good. Same problems as with cheap batteries on the poor performers, all losing power very quickly when worked hard.

- top price (ok, Duracell - we all know that brand) always consistent and trustworthy, also seemed to perform better in high power usage applications... but very expensive compared to the others! Now reserved for the most important devices only.

Another thing I noted was that some batteries got warm/hot when in use with high energy consumption devices. Nothing too serious (I always switched them off if I feared over-heating may occur), but I'm not sure I'd want to risk any chance of heat (or worse) when helplessly bound! 

Good luck with your build - I'm awaiting development with interest.  😁

MJ

[ltxrob]

yes battery life can be very variable....
hence my plan to do some unbound testing. 😁

[essanym]

Started working on some el Trina gets cuffs

I know what electromagnets are and I get what you're doing with them, but I don't understand what you meant with "el Trina gets cuffs".  Could you clarify?

Also, this is something I've been intending to build at some point so I'm looking forward to your updates.

[ltxrob]

Started working on some el Trina gets cuffs

I know what electromagnets are and I get what you're doing with them, but I don't understand what you meant with "el Trina gets cuffs".  Could you clarify?

Also, this is something I've been intending to build at some point so I'm looking forward to your updates.

nope. Neither do I. Sorry that was a complete and utter autocorrect that made no sense at all. Sorry.

[ltxrob]

Progress....... 
box, 3D printed battery holders and terminals. 
E-mags are not with me st the moment.

[Like Ra]

box

Nice one. Where did you get it? Are there any smaller (for one 9V battery only)?

[ltxrob]

Amazon and eBay have lots of electronic project boxes.
I went for that one because it allowed me a decent surface to bolt the electro magnets to and it would house the battery clips easily.
May evolve over time to hold an arduino and a few relays too.

[Like Ra]

What I could not find anywhere (ready) is round metal plates with a kind of skirting to prevent sliding the plate off the magnet.

[ltxrob]

What I could not find anywhere (ready) is round metal plates with a kind of skirting to prevent sliding the plate off the magnet.

my plan is to use 40mm plumbing external end caps... but of I cant find something like that ill just 3d print something that will act as a collar so that the catch plate cant be slid off sideways

hope the picture makes sense