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Author: Subject: Detonator casings
Brightthermite
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[*] posted on 21-10-2021 at 16:50


You should all do yourself a favor and go out and get a 12v lead acid lantern battery from Home Depot or Lowes and you wont go back to regular cell batteries.
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ManyInterests
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[*] posted on 21-10-2021 at 17:27


That's too much. 8 D-cell or even C-cell is plenty for my purposes. I made an electric match using 2 3-meter long wires to my RF module for a test and it light up nearly instantaneously. I did this with C-cells (D-cells are even more powerful). I cannot ask for more. I plan on putting my RF module in a box to shield it from any debris while I will be as far away as I can, but still within line of sight

Speaking of which I wish to showcase my expertly created hydraulic press!

H-press.jpg - 1.1MB
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macckone
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[*] posted on 22-10-2021 at 08:24


2 x 9v will provide 5 watts with alkaline cells, maybe more if you use lithium. You get some voltage drop but it is going to max out in that range.

Considering the light bulb is rated at half a watt, that is more than sufficient.

If you are doing a string of igniters, you may want a higher voltage and amperage potential. D cells are totally overkill. AA are plenty for this type of igniter system and 9v cells are sufficient. Assuming a single igniter. 6v is sufficient to cause the bulbs to burn out.

Professional systems charge a capacitor up to 100v then release the charge with the button push. But they are designed for a string of explosives. They also have safeties and such that are probably going to be lacking in a non-certified system.

Estes rocket launch controllers put out either 6 or 9v depending on the model. The 9v model uses C cells.
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MineMan
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[*] posted on 23-10-2021 at 23:15


Quote: Originally posted by ManyInterests  
That's too much. 8 D-cell or even C-cell is plenty for my purposes. I made an electric match using 2 3-meter long wires to my RF module for a test and it light up nearly instantaneously. I did this with C-cells (D-cells are even more powerful). I cannot ask for more. I plan on putting my RF module in a box to shield it from any debris while I will be as far away as I can, but still within line of sight

Speaking of which I wish to showcase my expertly created hydraulic press!



I don’t see that working. There will be a force on the cardboard bridge.

NHN and ETN are pretty stable stuff. Imho, you can do it by hand. Minimum amount is a beauty. Your making this way to complicated, unless you enjoy the process.
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ManyInterests
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[*] posted on 24-10-2021 at 14:14


Quote:



I don’t see that working. There will be a force on the cardboard bridge.

NHN and ETN are pretty stable stuff. Imho, you can do it by hand. Minimum amount is a beauty. Your making this way to complicated, unless you enjoy the process.


I've tested dozens of e-matches and will likely do more tests before the whole thing. Outright Failures are quite rare with my matches. The one thing you need to remember about ultra-thin nichrome wire vs 'just' thin nichrome wire is that it the 0.08mm and 0.1mm like to jump around, this means getting them to make continuous contact with the match head is tricky. I might end up having to use some of my 0.25 nichrome wire because it isn't as springy. I did manage to find a way to light up a match with 0.25mm nichrome wire using 2 AA batteries (alkalines. Steer clear of the carbon-zinc stuff for this purpose!) But if the wires are very long you will need more than just the 3 volts afforded by the 2 AA. 8 AA batteries worked, but I'll use the C cells because I want to guarantee they'll work.

To make sure that the wire touches the matchhead with 0.08mm or 0.1mm I've wrapped a bit of the wire around the head. This does create a short, but in this case it is actually what you want because shorts in a nichrome wire do cause it to get white-hot very quickly

And yes, for me it's ALL about the process!
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katyushaslab
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[*] posted on 25-10-2021 at 02:18


For your batteries, skip the shite alkaline cell ones and just buy a LiPo pack + charger with a high discharge rating (high "C" value) from any hobby/RC store online or locally. Usually I go for ones around the 11-13V range for lighting electric matches. They will instantly heat up even the thicker nichrome at the end of a long wire.

Another good option is the portable jumpstart boxes for cars, but those are heavier.

You seriously do not want to under-power your initiation setup, nothing is worse/more likely to kill you (or someone else) than a device failing or going into an unknown state because you cheaped out on the initiation setup. You can't just leave it there and fuck off, you have to deal with it.
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Laboratory of Liptakov
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[*] posted on 26-10-2021 at 08:41


Today's Li-Po's discharge current is even 80 times higher than the value written on the cells. So 1000 mAh will supply an instantaneous current of 80 A. 1800 mAh will immediately supply 144 A. Therefore, it is necessary to focus on a quality switch (relay). Which can withstand a surge.



Safety explosive Alfred Nobel 1867. Safety ecologic detonator Dr. Liptakov 2015, inventor CHP and Lithex
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ManyInterests
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[*] posted on 9-11-2021 at 19:45


Absolutely Li-Po batteries are the best for this sort of thing. But they're very expensive and I don't have any (unless you count the power bank I have for my phone).

Quote:
You seriously do not want to under-power your initiation setup, nothing is worse/more likely to kill you (or someone else) than a device failing or going into an unknown state because you cheaped out on the initiation setup. You can't just leave it there and fuck off, you have to deal with it.


Absolutely. This is why I've done more testing regarding this than anything else. I am very confident in current setup. I've already several test caps using black powder, nitrocellulose, and sugar-chlorate mixtures and none have failed to go pop. I tested them with lower power battery packs. The one I will be taking with me on my final test will be substantially more powerful.

Again this is not to say I don't think that Li-Po battery packs aren't good. They are the best, but my current setup is already above and beyond.
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