Project Homebound

Selfbondage software and other kinky developments

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0385
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Joined: 09 Jul 2012, 23:36

Re: Project Homebound

Post by 0385 »

I had an idea for a stockade lock with a low power magnet. You know how some people lock two sliding doors with a long wooden (curtain) rod?
Like that, but upright. so instead of stopping two doors from sliding side to side, it stops two halves sliding up and down.

Replace the rod with an asymmetric metallic tumbler that will always fall/tilt to the side to keep the slides from locking unless a magnet pulls it back.
But when the magnet is active, the tumbler gets pulled into place and locks the two halves.
But if for some reason power goes out, it will always be in its default unlocked state.
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kinbaku
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Joined: 10 Jan 2020, 20:26
Location: Belgium

Re: Project Homebound

Post by kinbaku »

0385 wrote:I had an idea for a stockade lock with a low power magnet. ... ... Replace the rod with an asymmetric metallic tumbler that will always fall/tilt to the side to keep the slides from locking unless a magnet pulls it back.
It is an interesting idea :!: When the metallic tumbler is nearby in a container, pulled by a light elastic all the slides remains open, but when the electric magnet is activated, everything is closed.
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GeneralError
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Re: Project Homebound

Post by GeneralError »

GeneralError wrote:
thatthat21 wrote:
GeneralError wrote:The magnet I ordered from wish https://www.wish.com/product/5b5cd464ff666512b9871a11. It is a complete little module that can be directly connected to microcontrollers without worrying about freewheeling diodes and ampere consumption. There are similar modules available in the typical shops.
Does this one get hot after running for a long time? With a lot of the round magnets they seem to get hot after running for a time. Not sure if they are just over volting them or what but just thought that I would ask about the temp. I might just have to get a few of them. I have a few extra https://www.particle.io/ cell and mesh versions showing up soon for another project so going to test with them as well.
I made a testrun for >3 hours. The magnet was constanty on and had to carry a little screw drive as weight. In my setup it is powered by the 3.3V of my ESP8266 board. The magnet was not even lukewarm.
Meanwhile the electro magnet got a nice 3d printed case and I connected the magnet to the 5V power pin. With that 5V it got significantly hot. It is still ok for the plastic and the devices. But you won't touch it anymore. I changed the wiring back to use a 3.3V pin and made another test. It is running now since 12h and carrying a M8 Screw plus nuts. The temperature is ~40°C. That's ok I think even for long time usage.
hbaemr_caseactive_ScrewNut.jpg
OrgasmAlley
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Re: Project Homebound

Post by OrgasmAlley »

That seems a very reasonable temperature, yes.

The heat generates is independent of what the magnet might be holding, by the way, except to the extent that the held item might act as a heat sink. Holding force is directly proportional to voltage in these magnets.

If you would like to cool it down or be able to increase the voltage for more power, you could in fact use a heat sink. The case of these magnets offers very little dissipative capacity. This introduces mounting complexity, of course, although your 3D printing approach might easily accommodate the magnet with a 20x20mm heat sink attached with thermal adhesive. For example:

https://www.banggood.com/5Pcs-20x20x15m ... rehouse=CN

Or if you want to get super serious:

https://www.banggood.com/3-In-1-Heat-Si ... ehouse=USA

The fan there is a standard 30x30mm... the included fan is 24 VDC but 5VDC fans are readily available. I know this -- and probably the whole post -- is overkill for your needs here, but it might be useful to someone. My electromagnetic handcuffs include a fan, although it's excessive under the vast majority of conditions. However, multi-hour use in 90+ degree ambient temps did eventually make the billet aluminum body hot enough to be uncomfortable. I'm using a bigger magnet, and it does generate more heat. With a small fan, the whole thing remains within a couple degrees of ambient temps.
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