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Ice
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Thanks man!
Has anyone tried using MMAN (a primary explosive that's so insensitive it needs a flash powder charge to set it off! Perhaps FOX 7 would give some
dramatic reults... Or you could do it like the Swedes (military), simply obtain some military grade pentyle, its stable, cheap, reliable, powerful and
burns really fast! Very good for shaped charges. 
If you make it bullitproof, they\'ll just make a bigger bullit.
If you make it waterproof, they\'ll just make a deeper ocean.
If you make it foolproof... Then they\'ll just find \'emselves a redneck!
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Boomer
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OMG... 
MMAN or MAN (dont say monocarbon dioxide do we) is a *secondary* of the UN/GN/EDDN/HDN family. I made some, and am currently working on a cast AN comp
with MAN to lower m.p.
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Ice
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Hmm
Well, If MMAN is a secondary, it's an awfully unstable secondary.
Let's simply agree to disagree?
How much does MMAN cost to make?
Is it military, hard, medium, easy or (politically incorrect) to make? 
Again...
I first got the impression that the explosive was supposed to go outside of the lining, but on the picture on the last page, the explosive seems to be
inside the lining. Which way is it?
[Edited on 30-3-2006 by chemoleo]
If you make it bullitproof, they\'ll just make a bigger bullit.
If you make it waterproof, they\'ll just make a deeper ocean.
If you make it foolproof... Then they\'ll just find \'emselves a redneck!
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chemoleo
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There is an edit function you can use, no need for double posting.
Also, we don't agree to disagree, we back things up with hard data, not with random assertions.
Also, before you start asking quite obvious questions, please read the thread beforehand.
At last, all this is way off topic. This is a fantastic thread that doesn't deserve worthless posts.
Never Stop to Begin, and Never Begin to Stop...
Tolerance is good. But not with the intolerant! (Wilhelm Busch)
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Ice
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| Quote: | Ursprugligen inlagt av chemoleo
There is an edit function you can use, no need for double posting.
Also, we don't agree to disagree, we back things up with hard data, not with random assertions.
Also, before you start asking quite obvious questions, please read the thread beforehand.
At last, all this is way off topic. This is a fantastic thread that doesn't deserve worthless posts. |
The "double posting" you're referring to was an internet f--k up, and was quickly removed. PLZ, read the post before referring to it, in order to make
sure it really does exist.
Ok, if you want to. MMAN is used in several detonators, such as the L-series (L for liten or small). This because it can be set off without an actual
explosion, thus it's a primary.
A shaped charge works thru compressing a lining into a high temperature, high velocity particle jet, that upon impacting it's target thanks to the
dynamic pressure reaches plasma and burns it's way thru a lot of armour.
If you place the explosive inside of the lining like Mr. Chris has on the previous page, the lining will open like a tulip and it's thrown outwards
like in a common grenade.
If you make it bullitproof, they\'ll just make a bigger bullit.
If you make it waterproof, they\'ll just make a deeper ocean.
If you make it foolproof... Then they\'ll just find \'emselves a redneck!
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Chris The Great
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| Quote: | Originally posted by Ice
If you place the explosive inside of the lining like Mr. Chris has on the previous page, the lining will open like a tulip and it's thrown outwards
like in a common grenade. |
I cannot comprehend how you could think I did that. The explosive was in the PVC, around the liner. I didn't say anything in my post that would
suggest otherwise.
????
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Ice
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| Quote: | Ursprugligen inlagt av Chris The Great
I cannot comprehend how you could think I did that. The explosive was in the PVC, around the liner. I didn't say anything in my post that would
suggest otherwise.
???? |
Ok, Than WTF is it you've put inside the lining? Why would anyone put anything inside the lining, a high yield particle jet may be powerful, but it's
very easily disrupted if the matter encounters anything before it has reached it's maximum compression. Any asymmetry at all in the
pressure crossection would cause the jet to break down from a solid beam to a cloud of superheadet metal. (this is why a small metal jet can kill a
tank; as the jet pierces the armor it is disrupted, and when introduced into a confined space... the crew is pasted along the walls. There are things
slightly bigger than your fist that could kill an M1 Abrams tank)
If you make it bullitproof, they\'ll just make a bigger bullit.
If you make it waterproof, they\'ll just make a deeper ocean.
If you make it foolproof... Then they\'ll just find \'emselves a redneck!
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Chris The Great
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Oh I see what you have thought... There is nothing inside the lining, the grey stuff is a piece of plastic glued on top of the pipe to keep the
explosive out of the lining.
| Quote: | | I then carefully made a round top from that little plastic thing from the inside of a pope bottle lid, and glued that to the pipe using more epoxy.
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That is what this part of the post is referring too.
Hope that clears it up.
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Boomer
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"This because it can be set off without an actual explosion, thus it's a primary"
So it detonates without exploding??? And again, it's a fucking *secondary*. Ever made it? You can hammer away on it, and melt/burn it with a
blowtorch.
"A shaped charge works thru ... a high temperature ... jet, that ... reaches plasma and burns it's way thru ..."
The jet is not even molten (450C), so NO plasma here. And it does not burn through, but plastically displaces the target material.
Please, some reading before posting might make you look less clueless!
Oh and it's easy to make. Either bubble methylamine gas through nitric acid, then evaporate under vacuum. Or dissolve methylamine hydrochloride
in a slight access of nitric acid, and drive the more volatile HCl gas out. Just don't try to boil to dryness...
[Edited on 3-4-2006 by Boomer]
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quicksilver
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This IS a fantastic thread. One that I made sure to keep. However I have some questions that I could not find answers in depth to within the bulk of
the material here and what I have available at home....-=If it has been covered in the thread, forgive me...I couldn't find it, as it's now getting
pretty big=-
* The Japanese have made SC with a perforation at the apex (a hole at the top of a cone let's say), this is also used by some Eastern-Euro countries.
- Why?
- It appears to have some effect on the jet but yet it makes little sence from what I have read.
* From some discussion in this thread there appears to me a need for consistent strength within both the liner and the body of the SC. IF one were to
mold a cone for instance w/ copper powder-epoxy would not the body need to approxamate the same strength material? (and this goes with the next
question)
* Al is plentiful and easy to work as well as cheap. The statistics comparing it to other material show it to be not as effective as copper but close
to steel. With a liniar SC (like a channel+angle combination) would a weld need to be made at the joint or could that be accomplished without such a
strong connection (like epoxy)? - For that matter; what is needed for ANY SC in terms of OVERALL body coheasive strength? (I hate welding Al)
-thanks
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Boomer
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1. The very tip does not contribute to the jet, since no material can be squeezed out by liner matter radially compresssed (inwards).
2. Thickness *can* vary, but symmetrically, i.e. there are designs where the angle changes as well as the thickness. Just not along the circumference,
but only along the length!
3. You don't need to weld. Generally speaking the faster your HE the less does confinement matter. It does help, but less so than putting the effort
into more diameter and/or better symmetry.
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rot
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'...And at day 6, god created the Cylindrical Shaped Charge '
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quicksilver
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| Quote: | Originally posted by Boomer
You don't need to weld. Generally speaking the faster your HE the less does confinement matter. It does help, but less so than putting the effort
into more diameter and/or better symmetry. |
OK....... If I have my math in order what I am needing to focus on is the symmetry of the body (and the consistent uniformity of the HE within).
Therefore I take it that a prefabricated item is really the only way to go for optimal results...(?) Is forming a cone or angle by hand with sheet Cu
or Al just a waste of effort if the intention is real cutting utility?
Where I am going with this query is: if I limit myself to molded shapes alone or paper or plastic, is there any way to basically predict how much
proportionatly less effectivness in terms of cutting power one would have or is that just asking too broad or a question without all the variables
associated...(?) {example, HE : PETN, cutting 3/4" hot-rolled steel, compaction data, etc, etc)
I know the above has been touched upon with a post relating to the use of lightbulbs and this is why I ask....there we have possibly great symmetry
but a very thin material.
Thanks for taking the time: I honestly just don't want this thread to die without the input of the little idiocyncracies. If I'm pushing it too much,
I'll shut up.
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enhzflep
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Well, to cut a long answer short, in my many dreams i have found that with identical charge weights, cone geometries, exp compound and stand-off one
may expect a 50% loss of efficiency from Al tube to simple PVC. That said, using a particular construction technique results in more or less the same
results (give or take 10% penetration depth)
I.e - in my vivid dreams (hmm could've sworn i was there )
HMTD in a Al tube, using Al Pop can as liner @ 30 deg will penetrate to between 2/3 and 1/2 of charge diameter into forklift-tyne (fork). This holds
true for 9mm diam, 15mm diam, 18mm diam and 20mm diam. Any discrepencies i put down to density of charge.
As for symetry of construction - in a perfect charge one would find that the
entry/exit holes are highly symetrical and round. Any deviation from this ideal form can be accounted for by a lack of symetry in either the liner or
loading density.
In conclusion i use the rough calc of 1/2 cone diam = penetration into steel that a file doesn't want to touch.
6mm with 1gm HMTD, in 9mm id Al - hole diam 2mm
10mm with 5gm HMTD, in 18mm id Al - hole diam 4mm
Lemme know if pics wanted
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quicksilver
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| Quote: | Originally posted by enhzflep
In conclusion i use the rough calc of 1/2 cone diam = penetration into steel that a file doesn't want to touch.
6mm with 1gm HMTD, in 9mm id Al - hole diam 2mm
10mm with 5gm HMTD, in 18mm id Al - hole diam 4mm
Lemme know if pics wanted |
If you have pics that would be a plus. I was very interested in design, per se'. You used a cone in this instance: what were the dimentions and
contruction meterials used and how would you have improved upon them from the experience you have had thus far? Have you ever used a liniar SC (angle
iron-type)?
An intersting point you mentioned is that your material target was quality hardened steel: that is very important to me as this whole project is being
looked at from the stand-point of utility. There is no point in simply making a loud bang.
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Lapis_infernalis
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This week I make somme explosive experimets with my explosive mate in my garden^^ (subsurface).
We think how we can build good cones for sharped charges.
He ore I had the idea that you can heat a glass pipe and stretch it. Than he make the first sharped charge with a straw, some PETN and a self-made
glass cone. With it he make a hole in 2mm steal. The exit was a 1mm hole.
After this I made a charped charge too.
Here is a chart of it:
http://s30.yousendit.com/d.aspx?id=29SWSWOVU59SF3PLS4KBPMFWY...
It made a 5mm deep hole into a piece of steal. 
[Bearbeitet am 9-4-2006 von Lapis_infernalis]
Sorry for my bad grammar
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enhzflep
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| Quote: | Originally posted by quicksilver
If you have pics that would be a plus. I was very interested in design, per se'. You used a cone in this instance: what were the dimentions and
contruction meterials used and how would you have improved upon them from the experience you have had thus far? Have you ever used a liniar SC (angle
iron-type)?
An intersting point you mentioned is that your material target was quality hardened steel: that is very important to me as this whole project is being
looked at from the stand-point of utility. There is no point in simply making a loud bang. |
Sure thing buddy, Okay first things first. Most literature says that you need at least 1 cone diam of explosive above the apex of the cone as this
allows the det wave to be more or less flat when it hits the cone (as opposed to travelling in all directions away from the det), following this 1
cone diam(i use cone len) we need to have the length of the cone, followed by about another diameter to allow for the (internal) stand-off, and
finally about another 1/4 diam spare at the top above the explosive. - So we need a tube that is about 4 times as long as its internal diameter.
Next, the lit also says that you get a longer and faster jet that particulates after travelling a smaller distance when using 30deg as opposed to
anything larger, sooo we only have 1 diam stand-off - this however also means that easy to use
Al becomes more attractive - however due to its weight you need more of it to do the same damage. Simple - use 3 layers instead of 2. Better symetry
and weight. Simple.
I also use the idea mentioned somewhere else here or RogueSci about internalizing the standoff this makes for better retention of the cone i.e energy
goes into deforming rather than moving it.
Similarly after making such a cheap and nasty construction it would appear to be a waste using an expensive ($1.50) pvc or steel cap - so i use wait
for it.... plasticine - has plenty of weight plus i dont really care where it lands (sure behind something is easy, but how many of us can do this
with a 'roof' overhead?)
Okay then with this long winded explaination out of the way, lets take an actual example.
Casing: 17mm Id, 20mm Od - 70mm long
Just something i had left over from making rocket engines
StandOff: 15mm section of estes rocket engine
Basically a tube that is a tight fit inside the body to hold the rim of the cone.
Cone: Take a soda can, cut the top and bottom off then cut it open into a large rectangle. Next anneal this on your kitchen stove or any other similar
gas flame. Now measure the Id of your casing and multiply this by 3. This is the diameter of the circle that you need to cut out. Cut a _straight_
line from the edge to the middle. Roll up into a cone 3 layers thick and keep the rim as even as possible (3 layers whole way round).
Det: Take 4cm of 5mm drinking straw, seal one end with hot glue, press in ~3cm hmtd then hot-glue in either wires or fuse.
Putting it 2gether: Place cone on a flat surface, press body over the top until cone is in, then press body over you stand-off tube. This keeps
everything straight.
Gently pour in hmtd, pressing with a piece of wood or plastic. Do this until you're around about 1cm from top.
Next wrap the plasticine around the lower 1cm of you det, before inserting whole assembly into end of S.C
This both centres your det and provides something for the explosion to 'push against' as the cone is deformed (plasticine weighs plenty more than the
1.4g or so that this cone weighs)
Place on target, light fuse then run like a crazy bastard (keeping a large rock or tree between charge and anything
else of value - like yourself )
Well, hope this helps you somewhat and if not, hope the pics make it more clear. (also have vids)Oh yeah, nearly forgot - nope never tried a linear s.c. These puppies are loud enough as it is, plus i'm a lazy
bastard and they always seemed like more work
enhzflep...
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enhzflep
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Haven't got any web-space, additionally i couldn't work out how to attach (if u even can) more than 1 file to a post, so here is the vid of the above
holes being made. If quality is too shit i can re-post individual vids or mail them to you. Orig was about 175Mb dvd quality mpeg2 720x576 @ 48Khz
stereo
enhzflep
Attachment: SmallSCVid.wmv (445kB)
This file has been downloaded 1713 times
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Chris The Great
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Nice work, good to see a lot of tests being done to get some results. Good to know what we can expect in temrs of consistancy.
Your high loss of efficiency going from Al to PVC is probably from your explosive choice, rather than an inherent thing. Using a very high VoD
explosive (RDX, methyl nitrate, etc) I would expect this to not occur... although if someone would actually do a few tests that would be great.
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Boomer
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Yeah, good work. Yust a tip, try 42 degrees to save some heights, it is said to give better penetration. Jet speed is not everything (jet mass gets
lower at narrow angels).
Although a little finger spanking is in order now (while there's something to spank ): HMTD, being a primary and a sensitive one, is not a sensible choice for the main filler!
Not only can 5g easily remove a whole hand, you will also get much better performance (read 2-3 times) with a denser/faster secondary.
Ask Al, he had it detonate from withdrawing a wooden dowel from a cap. The same happened to me while trying to plasticise it, using very little force
while mixing on a wooden board.
What made us survive unharmed are the sub-gram amounts involved!
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enhzflep
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Ooops. Thanks for the heads-up Boomer. Not that it really makes a huge difference, (with the sister of the mother of satan)but i always test for
friction and impact sensitivity. The batch that was used for above tests was found to be unreactive between 2 rough surfaces (anvil & hammer)
until a weight of over 1kg (9.8N) was rubbed across it through a distance of 10cm @ about 3 osc/sec. And i can tell you that i sure as hell am never
going to be that energetic when pressing something.
Additionally, to reduce friction i always press with a dowel that is sub-calibre by at least 25% of the diam to eliminate those pesky
friction conditions.
But you are of course dead right Boomer, it's not a sensible choice, rather silly some might say - but its not through ignorance that i do this.
Doesn't always do what i want, but i love my body and am not particularly keen on being covered with part of it. - Hence the 20mm blast barrier and
40cm long dowel attached to another to keep me away from the top and sides of said device.
Btw, what were you plasticizing it with? Not a nitro-aromatic was it? Did a
search to no avail. Whenever i want to do that i use petroleum jelly in naptha. It's just a pain letting it dry.
Oh and 'bout using 42deg. Hmm thanx must try that when i get something with less of a mind of its own.
enhzflep..
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Deceitful_Frank
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My first shaped charge
Hello all!
Yesterday I acquired a strong cylindrical Al tube, closed at one end and of internal dimensions: ID 25mm and height 42mm.
Measured with water, it has a capacity of exactly 20ml and thinking this could be the start of a small shaped charge, I set about constucting a
suitable Al cone to form the cavity.
Using a circle of discarded pie tin, I cut along its radius to the middle and coiled it around its apex exactly twice to form a near perfect 60 degree
apex cone. I then smeared a thin layer of epoxy across the surface of the foil and reformed and allowed to set hard.
Very impressed with the cone as it FAR exeeds what I was expecting to create by hand
It now fits snuggly over the end of my closed Al cylinder to give a finished capacity of 17ml for the SC.
Because of the shortness of the tube and the angle of my cone however, my charge only has a headheight of 0.9 CD. Do you guys think this will make
enough of a detrimental difference for it to be worth my while spending an hour forming another cone with a more obtuse apex to correct this?
I am thinking of a liquid explosive for this charge and EGDN, being the most powerful and reliably initiated explosive that I can make, is the
probably choice. Besides, I have 40ml dry and clear in the fridge as I type! 25grams of this wonderful stuff should fit inside.
One last thing for now... INITIATION!
I'll be drilling a hole in the top but I've not decided on the best way to construct the small but powerful cap that would be needed to make the best
of this charge. Two things are certain. I'll be using HMTD and the det must not protrude too far into the case or i will just make the lack of
headheight situation worse! Any ideas?
Oh and what kind of standoff would you guys suggest and do you think that firing this over the 42mm slab of steel I have in mind is being
overambitious?!
Thanks in advance.
[Edited on 11-4-2006 by Deceitful_Frank]
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quicksilver
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enhzflep -
Yea! That's what I needed! And this spured an idea. I have all sorts of rocket material as that is what I really do with most of a pyro hobby. But
the motor tooling (nozzle tooling) may just be the ticket as I have some that I know forms a cone and was not useful due to it's poor angle (for a
rocket).... you have spured an idea; and with the correct dimentions it may work. Pic's to follow.
Frank:
I read your PDF file. I also attempted what was shown but - damn it I don't know if it's that I am poor at arts and crafts or badly unco-ordinated but
cone-forming is very difficult with sheet Al. Did you just practice and practice forming the correct angles? It's not easy. The concept is a sound
one; & I have access to Hell of a lot of copper sheet but I wanted to get to the point that I could work with Al and form the cone in the
diamentions I wanted before I used up any copper. The trick with the pie tin seems quite sound.; how would youhold together a stronger material as I
don't think super-glue would do - or would it?
[Edited on 11-4-2006 by quicksilver]
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Deceitful_Frank
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To form a cone of one layer using a circle of metal foil you decide on the top apex angle of the cone that you want, subtract from 180 and divide by
2. You then take the cosine of this nubver and multiply by 360 to give you how many degrees of a circle you need to take the cut sides, bring together
and form the cone.
A 60 degree equalateral cone is easy as all sides are equal and cos60=0.5, 0.5X360is 180 degrees so just take a half circle or do what I did and wind
a cut full circle around twice.
Like you said it isnt easy. I find that theres a certain thickness of foil that corresponds to a certain diameter that is thick enough to remain
elastic but thin enough form by hand. Whether or not this ratio is near to the ideal 4% thickness of liner to cone diameter ratio I dont know!
I have no access to copper sheeting but Al foil of great variety of thicknesses. I'll practice with Al for now
As for making the double wound cone strong. At least for this small size, Three minute epoxy is great. I prewound the cone and mixed the Epoxy for 45
seconds. This givs me a good 2 minutes to spread over HALF of the foil circle and slide into shape. I then held it in shape for 3-4 minutes and BINGO!
A perfect and strong little cone. As you can see in the picture, I used the surplus 2-3mm folded back around the Al tube.
The cone will be glued into place with epoxy and I'll use duck tape around the base of the cylinder to make all secure and tidy.
PS... I have no PDF.
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quicksilver
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| Quote: | Originally posted by Deceitful_Frank
One last thing for now... INITIATION!
I'll be drilling a hole in the top but I've not decided on the best way to construct the small but powerful cap that would be needed to make the best
of this charge. Two things are certain. I'll be using HMTD and the det must not protrude too far into the case or i will just make the lack of
headheight situation worse! Any ideas?
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There was a thread that had a plastic-HMTD or AP concept; the idea being to plasticize peroxides. The author used Elmer's glue to form a putty w/
peroxides and he claimed it worked very well. If space is an issue, forming a small putty ball on the end of a fuse may create a det that is ultra
compact, this could be shielded by some method such as foil ,ect....if an easily detonated material is used such an idea may work.
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