Perverting the "L Delay":

Ideas and instructions how you can make your own bondage toys.
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Sir Cumference
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Re: Perverting the "L Delay":

Post by Sir Cumference »

BornThisWay wrote:The reason the L-Delay works is because typical Solder is made from Lead and Tin. Both of these metals have a good Ductility rating.
Meaning that they will stretch and deform under tension.
....
Yes, and no. (actually, primarily "no")

To give an example:
.999 silver is amazingly ductile, and it will stretch and deform under tension, yet it will not work in the L-delay.
You can hang a weight from the silver wire that is close to the breaking load (say 80%), and it will just hang there... and be there next week too.

What happens is about "creep".
Dislocations and defects in the crystal structure can migrate through it, making the material slowly stretch under a load that is far from the load required to break the wire in the normal sense of "apply enough load to break it"-breaking.
It is about movement of atoms in the crystal lattice and the relation between the absolute temperature and the absolute melting temperature of the alloy.
In a thicker lead bar, you can see a "stepped" deformation.

Creep is about melting point, temperature, ductility, load and time.
Lead-tin solder is ductile and low melting, meaning that it will show pronounced creep at room temperature.
That is why it is working.


This site has a very nice movie showing the creep of a 30 centimeter piece of solder ending up being more than four times as long.
The weight attached is 10% of the load that would break it the normal way.
http://www.mtu.edu/materials/k12/experiments/creep/
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BornThisWay
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Re: Perverting the "L Delay":

Post by BornThisWay »

Got it.
Since silver has a melting point of 961.8°C,
silver it would only stretch like Lead/Tin Solder if the temperature in the room was lets say maybe a comfortable 900°C?

Awesome video BTW.
This has become a favorite release method.
I think Anna should include it on the home page so it doesn't become lost in the archives.
lugnuts
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Re: Perverting the "L Delay":

Post by lugnuts »

This is brilliant, sir! Congratulations to Sir Cumference for a real advance!

::lugnuts presents Sir Cumference with a gaudy medal on a pink ribbon::
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Sir Cumference
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Re: Perverting the "L Delay":

Post by Sir Cumference »

Oh goody!

I'll wear it next time I see the old boys at the pub!
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Re: Perverting the "L Delay":

Post by Stretched out »

So it see s I'm back into a kinky phase again, so looked out my reel of solder ready for some fun, as this used to work so well as a timed release... but it seems I've only got lead free, or huge 2.5mm wire left, so I'll have to get some new stuff :(

Being as the length plays a factor in dependable repeatable timing, I mage a small jig for preparing the links.
Its just a piece of scrap wood, with some 5.5mm holes drilled into it. Then some 6mm bolts screwed innto the holes and their heads cut off. With the three posts, I can easily make a few different lengths for longer or shorter breaking times from a set weight. With a bit of care, failure was usually within 10 minutes of the expected time.

The 6mm eyes of the links eadily fit onto the pin of a couple of small shackles, which makes rigging up easy.
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Sir Cumference
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Re: Perverting the "L Delay":

Post by Sir Cumference »

Now that is a nice jig!

A great idea, that should greatly improve the consistency og the delay elements.


But if the choice is between length and weight, I think variable weight is easier to work with.
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Re: Perverting the "L Delay":

Post by Stretched out »

Indeed, varying the weight is the easiest variable to change. But smaller weights get closser and closer to a vertcal on the graph, so you can easily end up with a lot of unexpected time on your hands.

This time, the only solder that I could get locally was 1.2mm diameter, so significantly thicker than the electronics grade stuff I'd previously used. With the thicker wire, I opted to make another jig with a larger spacing of 70mm. And just go with varying the weight.
After several tests, I had a graph very much like yours on the previous page, with weights varying between 1.1kg and 1.9kg :roll: Not particularly good to have that dropped next to you, but handy for pulling a latch :D

Image

One variable that I seriously underestimated was temperature :? After testing in the kitchen, where the temp is 12deg, I went out to the garage loft where it was only 4 or 5deg. The tested hour lasted 1:45 which was a long time when all your wearing is a blindfold
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Sir Cumference
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Re: Perverting the "L Delay":

Post by Sir Cumference »

That was actually a problem with the L-delay too.

It came with a temperature correction chart for a better estimation of the time.
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