Unconventional Shaped Charges

Quote: Originally posted by greenlight

Oh no, damn welds....Hasn't this happened to you before previously as well with another test? At least you know the cones function fine. That's still a whole lotta depth for a 19mm diameter SC, I would be pleased. Will you be repeating with a new target to find the actual full penetration? [Edited on 14-10-2016 by greenlight]

Thanks greenlight yep broken welds again thats what you get for being a tightarse and useing bits to make a target up.

Yes im pretty rapt with the result the copper casting machined ok so i had the feeling it would work.
I am going to make some more etn tomorrow so i can have a go again soon on a one piece target.

Quote: Originally posted by NeonPulse

Nice! Looks like we are getting good at this. I was actually thinking of using the lost wax casting method to form a cone out of silver. It would be interesting to test I think, just never got around to it yet.

Thanks neon pulse .
Lost wax casting a silver cone should work well, would work ok on Werewolfs as well.

Quote: Originally posted by Zyxel

How to remove plasticizer from my plastiqe.I dont know which type of plasticizer is used in this military plastiqe.I was tried with nitro thinner but it disolve petn.I will try next time with pure pressed petn wiht aluminium or magnesium cone.

Quote: Originally posted by Zyxel

How to remove plasticizer from my plastiqe.I dont know which type of plasticizer is used in this military plastiqe.I was tried with nitro thinner but it disolve petn.I will try next time with pure pressed petn wiht aluminium or magnesium cone.

Nah i wouldnt bother if the binder is less than 15% Zyxel you just need a slight redesign of your setup .

This is the setup i used to get 78mm depth its only a sketch but it shows everything you need to know

Cheers Nux.



[Edited on 17-10-2016 by nux vomica]

Quote: Originally posted by Thraxx

It seems me, that the explosive for shaped charges with highest possible VoD between 8 -9000 m/s without acetanhydrid is possible prepare so: 1. Step- prepare the hexamin dinitrate HD and dry it. 2. step -prepare Dinitropentamethylenetetramin DPT :0,64g of HD + 19,5ml H2SO4+3,9ml formaldehyd (5-15C to 40g of ice,neutralised NH4OH) 3. step-like described by A.F.McKay et al,Can J Res 27B,462-468 (1949): The DPT to solution of NH4NO3 diluted in 99%HNO3 and heated to 70-75 C for 15 min and throw it into ice.There will be mix of 30%HMX and 52%RDX. -- This mix with negative O2 bilance can be melted with ETN (prepared with 100%HNO3). [Edited on 15-10-2016 by Thraxx]

Quote: Originally posted by Thraxx

I have heard about the incompatibility between RDX and sulf.acid,but I red by Urbanski about W process and there was written,that the spent acid contain 14% H2SO4 and despite was there 90%yield.May be the decomposition need some time .Reportedly the decomposition of RDX begin by contact with sulfuric acid over 70%. To the detonation Velocity-there is need highest possible density.Highest density is in crystal or in the melt.The pressure 2000 kg/cm2 make loading density 1,6/with over 8000 m/s by Pent or RDX and how to do it against the thin copper? Therefore it seems me,that better is either melt or big crystals+liquid explosive like NG (1,59), NIBGTN (1,68),HN Sorbitol (1,58g/cm3)or EGDN (1,48). ((melt ETN 1,6 g/cm3 with 8100 m/s,DINA 1,488 with 7580m/s )) I did small shaped charges like Axt-bullet into the cartridge shell with pentrinit and it worked well,but not three diameters of steel.I had suspicion,that a part of pentrinit doesnt its work because the critical diameter in the thinnest parts of charge. Therefore it seems me,that the better charge will be from crystalised Pent and the space between crystals filled with liquid NG.

Took a small EFP charge I made out because I haven't been out for a while and I am still preparing another 40mm EFP.
This one had a metal casing and metal tamper with a thicker liner to see if it increased the performance for a small size charge.
Liner diameter : 22mm
Liner thickness : approx 1.6-1.7mm thick
Charge material : PETN PE (15 grams)

Target was 10 mm thick steel plate and standoff distance was 80 cm.
Forgot to get photo of charge right before detonation but it was taped to a wood block.

I think the charge weight was a bit too much and overdrove the liner causing it to hit in two spots as can be seen in the photo with a bit of spalling around the entry hole.
I think if this breakup of the slug had not happened I would have got a full penetration. It nearly made it through and opened the back of the plate up like a half opened tuna can
Next one will be the 40mm version against a 19mm target.

[Edited on 18-11-2016 by greenlight]



[Edited on 18-11-2016 by greenlight]



[Edited on 18-11-2016 by greenlight]

Quote: Originally posted by Thraxx

The dinitro tetramethylol ethan tetranitrate is me not known I must take a look in Fedoroff.I hope,that this stuff is more stable than NIBGTN. //Manitol hexa (?)nitrate made with 65% nitric acid has a m.p. about 82 C,but it is a mix of pentanitrate with 6 % of hexanitrate.Similar is with ETN-made 20 g E+50ml fuming nitric +100 ml sulfuric acid is really ETN with violant blow ,but the ETN made with weak acids is brizant too,but not of such power and its blow is weak. PETN from 65% acid is not Petn-look at the m.p.,there is about 90C with decomposition and shoul be about 120 C.// My idea was satted dilution of solid HE(1) in the liquid HE(2),which is solvent .Such hot dilution fill the charge shell without bubbles and by the cooling crystalise the solid HE(1) and build the crystal matrix which detonate in crystal velocity and carry away the liquid HE(2) for to detonate of such high velocity too.NG is able to detonate even 9000 m/s .Necessary is the strongest possible initiation. Such matrix could be done in gelatine too,but it seems me,that NC make it slow. In very small shaped charges would be better some nitrated primer.

Questions:
-Do you type by holding your breath?
-Don't you have a "enter" case on your keyboard?
-Are you trying to write with the minimum space at screen?


It would be much easier for us to read what you post and follow your ideas/point if it was a bit aerated/less compact.

For the rest your idea is stil good to dissolve and allow for crystallization of two HE but:
1°) the cystallizing HE may be into an unsuitable lower density...since density of crystals often depends onto the solvent...so this is poker...you have to try and see if you are denser, equally dense or less dense than expected.
2°) Also if each compounds are dissolved into each other, the lowering of the melting point (freezing point lowering see colligative laws) might be such that the mix doesn't come back to a solid form or to a defined crystalline form (thus anarchic less dense glass transition).

With my proposed process (suspend the high melting HE into a molten low melting HE (a few degrees higher than mp) and cool immediately down afterwards) you at least know the density you will get.

[Edited on 18-11-2016 by PHILOU Zrealone]

"the cystallizing HE may be into an unsuitable lower density...since density of crystals often depends onto the solvent...so this is poker...you have to try and see if you are denser, equally dense or less dense than expected."

....I thought,that crystal is like melting point typicall for each stuff.If not,then it is a bad message for me.

I thought,that like liquid in the two fase system could be there ETN-NG overfeeded solution/ melt .It is solid stuff at RT,but at abbout 40 C it melt .Stabilised should it be through amin TMTNA(R Salt) which should be there moreover like fuel.Like crystals trajectory could there be RDX made through hot aceton solution .
(Shells of very diffrent shapes could be easy made of galvanoplastic copper. Sense of such shaped charges I see in the combination of diffrent materials under pressure (like jet) or in detonography.The armor pierced function is problem of army.)
picture-ETN/NG melt

Just cut up a target that i fired a 19mm shaped charge at and found that either i had too big a charge or haveing two different explosive together isnt a good idea.

The bottom around the cone was 14 grams of cast 2/5 ratio etn - ptn mix as used by neon pulse and Mr anonymous and the top charge was 12 grams of petn plastique,maybe that was a bit too much filling looking back now.

By the look of the copper spray on top of the target something went wrong half way through the jet travel as the hole is perfect and the carrot didnt enter the hole.

Penertration was around 36mm and hole was around 3.5 mm dia, the rodsticking through the target is 3.2 mm dia.




Oh well at least ive got some more cones ive been working on.




Cheers Nux.





[Edited on 5-12-2016 by nux vomica]

Give me a feeling of deja-vu
Gandalf hat

Iv'e not had a problem with the 2-5 cast ratio. This was devised by mr anonymous himself. The last one I tried the result was pretty good. The whole charge was homogeneous as far as I know, with the PETN of equal sized particles and density and just enough ETN to keep it nicely suspended. Too little ETN and the cast seems dry but too much and there's a layer of ETN on top which could ruin the wave. I think it is a promising filler if only it wasn't so dangerous to make bigger shots....


Anyway here's one of my latest shots. i decided to use PLX as a filler mostly because there was a debate between myself and a friend as to weather or not PLX would form a decent jet. of course i knew it would from experience but had to prove my point.
https://vimeo.com/193344377

I just wish i had of used more steel plates since this jet was not stopped by 10 X 8mm plus a 20mm slab on top.

I remember starting shaped charges and looking at a couple of steel sheets and wondering if i could make a decent enough cone to pass through them, Nowadays, it's Gee, i wonder how many plates could i get this cone through?

Nice cones there! are they cast copper?

[Edited on 6-12-2016 by NeonPulse]

[Edited on 6-12-2016 by NeonPulse]

Quote: Originally posted by NeonPulse

Iv'e not had a problem with the 2-5 cast ratio. This was devised by mr anonymous himself. The last one I tried the result was pretty good. The whole charge was homogeneous as far as I know, with the PETN of equal sized particles and density and just enough ETN to keep it nicely suspended. Too little ETN and the cast seems dry but too much and there's a layer of ETN on top which could ruin the wave. I think it is a promising filler if only it wasn't so dangerous to make bigger shots.... Anyway here's one of my latest shots. i decided to use PLX as a filler mostly because there was a debate between myself and a friend as to weather or not PLX would form a decent jet. of course i knew it would from experience but had to prove my point. https://vimeo.com/193344377 I just wish i had of used more steel plates since this jet was not stopped by 10 X 8mm plus a 20mm slab on top. I remember starting shaped charges and looking at a couple of steel sheets and wondering if i could make a decent enough cone to pass through them, Nowadays, it's Gee, i wonder how many plates could i get this cone through? Nice cones there! are they cast.

Quote: Originally posted by PHILOU Zrealone

Give me a feeling of deja-vu Gandalf hat

Funny how certain movies become classics around the world ,did they get the lips sync ok when they dubed it to your language or was it ilke when we watch a kung foo movies and the persons talking when the lips aren't moveing .

Quote: Originally posted by Tsjerk

Possibly the petn detonated faster than the petn/etn resulting in a double shockwave?

Did a quick test with an older batch of PE and thought this might be the right place to post the pictures as the test demonstrates the Munroe effect.
I just took a 25 gram block and embossed SM (for sciencemadness) in it in mirrored letters before placing it down on a 1.5 inch thick steel plate.

[Edited on 18-2-2017 by greenlight]



[Edited on 18-2-2017 by greenlight]

[Edited on 18-2-2017 by greenlight]



[Edited on 18-2-2017 by greenlight]

Yes Philou, you are correct

How did I figure this out, you will ask

I simply noticed that the lower left branch of the deto-printed "S" is much deeper than the uper right part...hence my conclusion...the cavity on the left acted as a shaped charge while the same cavity with an opposed orientation did not...so the detonation was obviously coming from the right side.
Also there is a strange diffuse patern at the right of the SM printing...

Quote: Originally posted by greenlight

Did a quick test with an older batch of PE and thought this might be the right place to post the pictures as the test demonstrates the Munroe effect. I just took a 25 gram block and embossed SM (for sciencemadness) in it in mirrored letters before placing it down on a 1.5 inch thick steel plate.

Very cool execution of the Munroe effect, Greenlight


A bit of old experimentation from my side below....did not turn out too bad either :

Quote: Originally posted by markx

Quote: Originally posted by greenlight   Did a quick test with an older batch of PE and thought this might be the right place to post the pictures as the test demonstrates the Munroe effect. I just took a 25 gram block and embossed SM (for sciencemadness) in it in mirrored letters before placing it down on a 1.5 inch thick steel plate. Very cool execution of the Munroe effect, Greenlight A bit of old experimentation from my side below....did not turn out too bad either :

Nice detono-graphy.

Just as beautifull as the leaves you let dry into a book .
Of course to do the same with your process would make heavy books for bodybuilders .

Wow, that's just a stunning picture, yours turned out much better than my attempt at this! Even the colour matches, blotted that chlorophyl right into the steel, maybe it can still do photosynthesis . Leaf-shaped charges, very unconventional... I remember seeing sort of the same technique for shooting holograms in very hard metals, resolution was in the nanometer range IIRC. You could probably magnify using a microscope and discern some of the finer leaf structures as well probably.

[Edited on 24-2-2017 by nitro-genes]

Quote: Originally posted by nitro-genes

Wow, that's just a stunning picture, yours turned out much better than my attempt at this! Even the colour matches, blotted that chlorophyl right into the steel, maybe it can still do photosynthesis . Leaf-shaped charges, very unconventional... I remember seeing sort of the same technique for shooting holograms in very hard metals, resolution was in the nanometer range IIRC. You could probably magnify using a microscope and discern some of the finer leaf structures as well probably. [Edited on 24-2-2017 by nitro-genes]

Thanks for the kind words, Nitro-genes!

Yea...this sample turned out most impressive and the fine detail was just stunningly precicely stamped into the metal. Although I tried to clean it up afterwards by leaching slightly in citric acid solution to get the soot washed off. That was not a good idea, as it made the image much flatter in appearance, still a very successful test though.

Just noticed the patern...

OAK Leaf :-) into a troll's footprint

[Edited on 27-2-2017 by PHILOU Zrealone]

Made a forming tool for more conventional applications :



Works pretty good, but the copper has to be annealed several times inbetween of the pressing or the tip of liner will become too stretched and develop cracks.

Quote: Originally posted by markx

Yea...this sample turned out most impressive and the fine detail was just stunningly precicely stamped into the metal. Although I tried to clean it up afterwards by leaching slightly in citric acid solution to get the soot washed off. That was not a good idea, as it made the image much flatter in appearance, still a very successful test though.

Maybe finely polishing the plate before shooting some delicate structures into it may help getting even higher resolution. Noticing from the unblasted area of the plate, the surface is kind of rough, which would act like "background noise" for the image produced. Wondering if using a lotus leaf (water repelling nanostructures) would result in a metal surface having some interesting properties (May not be similar since a negative is produced). These kind of things may even have some unforeseen applications as well.

[Edited on 27-2-2017 by nitro-genes]

Quote: Originally posted by nitro-genes

Maybe finely polishing the plate before shooting some delicate structures into it may help getting even higher resolution. Noticing from the unblasted area of the plate, the surface is kind of rough, which would act like "background noise" for the image produced. Wondering if using a lotus leaf (water repelling nanostructures) would result in a metal surface having some interesting properties (May not be similar since a negative is produced). These kind of things may even have some unforeseen applications as well. [Edited on 27-2-2017 by nitro-genes]

Of course using a flat polished surface will give immensly better resolution....the current test was executed in the spirit of "what the heck, let's see what happens" and had zero preparative actions done to enhance the contact surfaces.

That is a very captivating idea about the lotus leaf example ! There are many interesting structures in nature that once copied onto manmade materials could reveal extraordinary properties. One could possibly also get a more or less positive image on the witness plate after reshooting the negative against a new witness surface. Technically this may prove to be quite complicated though, especially if the pattern is very fine and stretches into the field of nanostructures....

Of course using a flat polished surface will give better resolution....Better is use a annealing metal, this is soft aluminium plate 0,5 mm.


............................Dr.

Recently i was asking an airconditioning specialist for these little copper things they called helmets. they are found in brand new aircon units to prevent anything from getting into the system before installation. they come in various sizes and i was able to get quite a few of them. this gave me the means to try some micro sized shaped charges with an effective looking liner. The inspiration was from the little commercial blasting caps with the cavity in the end which i thought why not try that idea but slightly larger? these little liners would also fit into a smaller tube if needed so why not try it?
so i proceeded to get some 10mm Al tubing i had around and coated the inside with some paint before J.B welding 6 of these liners into 6X 10mm diameter 40mm long sections of tube.
For each of these little devices i used a filler of 2.1g 2-5 ETN/PETN melt cast and 250mg of lead picrate/azide clathrate. - this is why i lined the inside of the tubes prior to filling them. we are still unsure of the molten ETN reacting with Al. i have not actually heard of a case of ETN actually detonating in this manner but there has to be some substance to this claim though..... each charge was wired to fier electrically and 4 of them were given copper wire legs as standoff which i marked at the required distance to be bent with pliers on site.
So i used 3 each of the bell/cone shaped liners and 3 of the hemisperical liners. one of each was given no standoff one 15mm and the final 20mm. obviously the conical ones seemed to perform the best giving nearly 4mm penetration into the steel bar i had as the receiver hoever the 20mm hemispherical did leave a little divit on the back side of the steel where the others did not. i was only able to remove the copper carrots from the 1st hemi and the two conicals so i couldn't really compare the results as a whole but the conical ones did look pretty promising. i cannot be entirely sure of the effectiveness of the hemisperical but if there was enough force to completely embed the copper into mid carbon steel bar and nearlt split it completely lengthwise it has to be pretty effective. there was a fracture that ran nearly the whole length of the 20mm bar. i still have many of these little things left to try out and of larger sizes too.
Man were these little charges loud for their small sizes. it would have been about as loud as a shotgun going off.



[Edited on 25-3-2017 by NeonPulse]

and the results. the first lots are befor i attempted to remove the carrots and some after.



[Edited on 25-3-2017 by NeonPulse]

Quote: Originally posted by Laboratory of Liptakov

You will need the base of copper triangle 2 inch and copper 3 mm thick. And EM over 7500 m/s. Distance 3 inches.

Quote: Originally posted by Fulmen

As much as I approve of the solution I seriously doubt if it will be worth the effort. The chances of getting a successful SC on the first try isn't all that great, can you afford to destroy the target? Liptakovs suggestion would be the absolute minimum size, and will require both high performance explosives and a very accurately constructed charge. A more reasonable size would be 3". The most sensible approach would probably be to drill a line of holes and then cut the remainder with the angle grinder.

You mean 3 inches wide? WOW. So we are talking about very high amounts of explosives then?
A piece of 3 in wide and 10 in long square steel tubing would need a lot of HE to get fulfilled.

Well, it was worth at least discussing the possibility of doing so.
I'd rather spend 3 hours cutting steel and clean all the mess than to buy expensive chemicals and babysit a chemical reaction that would probably take more time than cutting the plate with the angle grinder.

Thanks guys.

[Edited on 17-1-2018 by joseph6355]

Of course, that mechanical cutting will always easily than shaped charge...

Quote: Originally posted by Laboratory of Liptakov

Of course, that mechanical cutting will always easily than shaped charge...

But wheres the fun in that haha

Seriously though, it would be feasible if you were cutting it width ways, but length ways would use a lot more materials and I think would be hard to get an accurate cut.

Quote: Originally posted by joseph6355

I have a piece of 10 inches long and 3 inches thick steel that needs to get cut across its length. I don't have a plasma cutter neither an acetylene gas torch. The only thing I have is a 4.1/2" angle grinder. It would be a pain in the ass to actually split it in half using only an angle grinder. Is it possible to make a shaped charge that will cut it in half for me? First I get a square steel tube, make a cut in the center, cut it to a length of 10 inches, and then add a bent piece of copper that will get liquefied after the explosion and produce the molten jet. Will it work? There is also the danger of shrapnel. I'm basically making an elongated grenade. The steel tubing would probably fragment and throw shrapnel everywhere, so I was thinking about burying it deep inside the dirt before detonating it. And also if I use Picric Acid as the main charge, I would need to coat the steel and copper surfaces before casting anything. Here are some drawings that exemplifies what I said above: https://i.imgur.com/tRw03if.png Edit: [img] tag removed due to oversized image. [Edited on 17-1-2018 by joseph6355]

Something like this? I used a linear setup a few days ago. It was 17.5 mm thick and a copper lined linear charge cut it. It used 150mls of PLX. The problem is that the steel is now bent. If that’s an issue it’s best to stick to the angle grinder...

I even gave the charge a name. I called it the Bangsaw.

[Edited on 19-1-2018 by NeonPulse]

44mm EFP

I have been constructing a new 44mm EFP charge over the past weeks to try and punch a hole through a target that has resisted every attempt with a 30mm design.



The specs are:

▪Diameter = 44 mm
▪Flyer thickness = 1.5 mm Cu
▪Casing = PVC
▪Charge Weight = 26 g PETN PE (16% inerts)
▪Standoff = 95cm
▪Target = 20mm steel

I usually sight the charge with a high powered laser pointer which helps a lot as it is quite difficult to get a direct hit just by eyeing it. Of course the thing decides to shit itself today and makes sure it waits til I am at the test site to do it
The target plate is only the size of a dinner plate so it's a small area to hit but I sighted it by eye as best I could before inserting the cap and initiating it.
Walked back to ground zero and wow, shock and awe, it hit high.

It is quite a decent hit though and quite a wide projectile due to the low head height of the charge. As can be seen by the photos, because it was so close to the edge of the plate it penetrated for a bit and then lost kinetic energy to the side as it took the path of least resistance and slid off over the top of the plate (that part was the top, plate was stuck in ground). You can also see stress fractures in the steel.



Also take into account the fact that it would have hit at a 10° angle instead of straight on, and the plate was just hammered into the ground and had some movement.
Penetration from what I can record is about 13mm before it started moving laterally. Im sure it would have almost if not fully made it if the hit was direct. Can always try some barrel tamping if not.

Guess I will have to step it up to a 50mm and have another crack at it, but first to find another decent laser pointer.




[Edited on 15-10-2018 by greenlight]

[Edited on 15-10-2018 by greenlight]

Thanks NP,

I can't believe you linked that! I was watching that exact video earlier today.
Yeah, that copper shaped charge was just beautiful to watch, the detcord and shocktube looked nice too and you get a pretty good view of the shockwave in motion on the last one.

It still amazes me that such a lightweight liner weighing in the grams range hitting a barrel half full of water weighing multiple kgs has the ability and force to throw the whole thing 9 or 10 inches off the ground.

P.S. Looking forward to seeing the properties of that perchlorate complex you made

[Edited on 21-10-2018 by greenlight]

Hi everyone.
Thank you for all your informations !
Here, my results after many fails. I have tried with plastic container, but it don’t work correctly.
I read here that it need to be in steel pipe to work well. By chance, I’ve found a pipe of 2,4mm of wall thickness for 29mm inner diameter. It is thin but it’s a test.
Here pipe is steel 50mm long by 29 inner diameter.
The copper cone was made by galvanoplastie at 90° (if my memories are good) and the thickness of the copper is about 1,4mm (estimated by mass/area).
I’ve put 38,3g of melting ETN but bubbles don’t make me reach a good density… So sad.
The detonator was at center, and made by 1,5g of ETN powder electrically ignited by 0,25g of TATP.
The penetration was 45mm in classic S235 steel. (Stack of 8mm plates).
The ratio penetration/diameter is 1,55… Quite bad against military performances, but I’m proud of me !!
Hope it can be be interesting for you !

(Next stage : RDX powder with EGDN, better density and VOD !)
(And as I've not 50mm diameter pipe, I will try with concrete, I'm sure it will contain a part of explosion)
Have a nice day guys.



[Edited on 21-10-2018 by Uriel]

[Edited on 21-10-2018 by Uriel]

Purely for amusement purposes let's see how small one can go and still keep some focus from a shaped device.....

How about building one into a 5mm drinking straw....seems like a reasonable standard scale ?

First we are going to need a setup for makeing the cone for the "Tiny" device






Lets see if we can form some copper with our contraption:







Pretty decent 5mm cone, aye (0,15mm thickness)....



We are going to need some reinforcement around that to force the energy down and out the business end:





There we have it...the "Tiny" device literally buildt into a piece of plastic drinking straw with some Al reinforcement

The result of the test:

2mm stainless 304 sheet, standoff 15mm, charge was 100mg SADS+ 250mg rdx



The jet split, but definitely we have a focused action going on....quite unbelievable that it could be this small and still have a profound effect. The active part has a lesser dimesion than a .22 round...

Can we go even smaller?



[Edited on 6-1-2019 by markx]

Quote: Originally posted by nitro-genes

Nice, I bet homogeneously loading and aligning these charges is challenging. For loading, I think it might help if the cone is supported by the positive mold piece to prevent the liner from deforming. If the positive mold would also have a small overhang to support the casing, the liner alignment also wouldn't change during pressing. Another idea might be to preload the explosive in the casing, and press in the liner while it is supported by the positive mold. The liner itself might turn out to be even more precise if during pressing, one of the mold pieces would be spinning (using lubrication). To achieve homogeneous loading density, a PBX would also seem better as powdered RDX, 3-5% inerts or active binder would probably suffice, though performance may drop due to critical diameter. IIRC, particle size also affects critical diameter, so making the RDX crystals as small as possible would further help. Finely powdered PETN or so would seem even better for these diameters. [Edited on 7-1-2019 by nitro-genes]

All true and good suggestions ! But yes, the critical diameter is already on the verge as is, even for pure substance. I used ultrafine particle size product from an ancient experiment that I conducted with straight nitric acid and hexamine. It is actually the purest sample that I have according to melting point measurements and the finest, thus also the easiest to kick off in such small diameter. Even with this one I get problems of partial or no detonation sometimes. The Bachmann variety is hopeless in such application, at least if not specially recristallised to obtain very fine particles.
I actually intended to use penthrite, it is vastly superior for such small diameters, but I did not have time for a synth, hence the old rdx stock came out of hibernation. further downscaling shall be reserved only for petn based systems.

The loading is conducted as you suggested: over a matching support piece to keep the cone aligned and straight. You can actually glimpse at it in the "green picture" the hefty nail like object with hexagonal base on the right side is the loading support.
The liner should actually be finished in lathe after being formed to ensure even wall thickness. It does stretch out unevenly and has bad focus due to that. Also a final annealing run should be performed on it before loading to equalize the stress.

copper cone

Good device.... I recommend use one between annealing operation. For better thickness on peak of cone....

Quote: Originally posted by Laboratory of Liptakov

Good device.... I recommend use one between annealing operation. For better thickness on peak of cone....

copper cone

Thanks for details explanation, Marks. Useful information for anyone.....

I examined the paint bucket that I conducted the test in more closely and the crazy part is that the jet seems to have extended to more than 55mm from zero standoff level. The device had 15mm standoff from target and then 40mm of spacing between the target and container bottom.

That is the container bottom below the target:




The container itself has been turned to a sieve from the shrapnel of the aluminium casing (serves as an illustration to the importance of containing these metal pieces at all cost and choosing a safe location for any live testing to be conducted):




The situation at the container bottom is highly curious though....55mm is about 11 CD from zero standoff. I think some of the holes may have been generated by material flung out from the target, but the center one is covered in clearly a copper residue and suspiciously the pattern coincides with the triple splitting of the jet that can be seen at the target. Could it really be that the jet extended this far away from the actual impact point and still remained focused enough to go through the container bottom and into the concrete below?

IIRC, the splitting of the jet could be due to several factors: one is stresses in the liner. Spun formed liners can exhibit this behavior as well, which had something to do with the stresses in the liner material by the spinning operation introducing axial rotation during liner collapse. Also noticed that re-annealed the liner after spinning would mostly solve this. Can't imagine the pressing operation producing the same stresses in the liner as spinning, so maybe in this case the it may also be an effect of an overdriven liner. Was the 0.15 mm copper thickness of the liner measured before or after pressing? Also noticed you used quite some sub calibration. The 0.15 mm after pressing may be more like 0.12 mm after and with another 3 mm's of subcalibration, the liner would be more like ~1% of CD instead of the optimal 2% for a 60 deg copper cone. Maybe slower slug fragments could also explain the penetration of the bottom container?

Think I mentioned this before: Liner precision, charge alignment and loading density homogenity are the absolute key requirements for long penetrations. I think both pressed and spun liners may produce deviations in the order of 50-200 um, while IIRC, only several micrometers are allowed to produce >5 CD penetrating charges. Note that this kind of precision is even out of reach for most lathes! Or you would need to build one like this! (Still on my loooong list of plans )

https://www.youtube.com/watch?v=sFrVdoOhu1Q

Even then, any after machining on a such lathe would probably prove very challenging in practice anyway. Curious how professional liners are produced to reach this kind of precision exactly.

Regarding the explosive, PETN/NG as Axt also used would probably be one of the best for these very small liners IMHO.

[Edited on 10-1-2019 by nitro-genes]

copper cone

Also it can be too much highly energy on 0,15 mm of copper cone. Else words, copper cone is too thin for high energy from explosive. Therefore has behavior as flame from rocket engine. Because any unprecision of copper cone thickness is cause for fragmentation at so highly energy. Require it thickness 0,3 mm of cone with a same EM. Or 0,15 mm, but with weaker (slower) EM. After it you will (maybe) only one hole in plate....

Quote: Originally posted by nitro-genes

IIRC, the splitting of the jet could be due to several factors: one is stresses in the liner. Spun formed liners can exhibit this behavior as well, which had something to do with the stresses in the liner material by the spinning operation introducing axial rotation during liner collapse. Also noticed that re-annealed the liner after spinning would mostly solve this. Can't imagine the pressing operation producing the same stresses in the liner as spinning, so maybe in this case the it may also be an effect of an overdriven liner. Was the 0.15 mm copper thickness of the liner measured before or after pressing? Also noticed you used quite some sub calibration. The 0.15 mm after pressing may be more like 0.12 mm after and with another 3 mm's of subcalibration, the liner would be more like ~1% of CD instead of the optimal 2% for a 60 deg copper cone. Maybe slower slug fragments could also explain the penetration of the bottom container? PETN/NG as Axt also used would probably be one of the best for these very small liners IMHO. [Edited on 10-1-2019 by nitro-genes]

Yes, I did downengineer the liner thickness in fear of not having enough impulse to getting good focus in such a small device. And as life has shown things do not down or upscale in a linear manner....at least most of the times you expect them to do so, they won't
The liner thickness was measured after forming with a digital caliper on the outer verge, so not to cutting edge of precision standards, but gives a rough outline of the picture. The jet splitting is due to liner inconcistency as you mentioned. I've also seen similar pattern in pressed soft steel liners. Either because of uneven thickness or because of stresses that develop during forming operation. But very likely both factors are at play here, as the liner does not stretch totally evenly during forming and it was not annealed after last forming operation. Copper develops an incredible amount of internal stress due to deformation and this will most definately affect the jet formation. In ideal conditions the liner should be cut even on both surfaces after being pressed and then annealed before application to relieve the lattice stress. At the very least it should be annealed....machining this tiny detail in a lathe is challenging at worst
I had little hope for success, so I bothered not to do either. Not to mention I had to be disappointed again!

So I set forth to go even smaller this time (3,5mm liner):









And I machined a full set of tools for preparing the little contraptions:

Well, its time to test out the 3,5mm microcone device....


The annealed 3,5mm Cu cone (0,16mm wall thickness) is inserted on the support jig and 170mg of penthrite is pressed into the casing in two stages. The first 100mg stage is pressed quite dense and the second one (70mg) is left in a less compacted state to ease initiation. 100mg of SADS is compacted on top of penthrite as the last operation:




The microcone device is completed. It has 3mm offset (appr. 1CD) "built in" because of the cone support jig:



The device is fixed to a concrete stand with tape and another 6mm worth of offset is added:





1,25mm 304 stainless sheet is chosen as the target and the device is configured as following for the test. I must note that this is the same sheet of stainless used in the previous 5mm "Tiny" device test. I assumed it to be 2mm stock, but upon measuring it comes out just about 1,25mm thickness :




After the test we have complete and utter success. The target is cleanly penetrated with a nicely focused single jet and there is no splitting. I also managed to retrieve the bottom and top parts of the aluminium casing:



The jet channel and the cone that formed it side by side. The cone in the picture has a broken tip (careless forming ruptured the tip of the cone), but it still serves as a scale indicator:


Quite amazing really....even the 5mm device seemed impossibly downscaled for a successful jet formation and here we have a 3,5mm device that displays full functionality. Could we go even smaller.......say a 2mm device?

copper cone

Good successful. It seems, that spherical - bulb peak of cone is better. And else angle I see, estimate. Also small main charge. Only 170 mg. Stainless plate is same, 1,25 mm. Or 5 mm steel. A lot entertainment with minimal EM..........

While going through the miniatures of the photos you posted I was like "Why would he post a photo of an empty caliper?" lol. Any smaller and you would need to go "Willard Wigan" style probably! Really love the toolset you made for the miniature liners btw!

The relatively large penetration hole is probably mostly the result of the hemispherical part of the liner (This part produces a slower jet than the conical part of the liner). Having a slight trumpet shape and/or sharp cone and >2 CD headheight/waveshaper above the liner, the charge produces only a very narrow jet channel. Made a 17mm charge this way once, it blew a hole through 5 cm of steel, but the only thing visible was the smallest pinhole trough the steel for which I doubt even a needle could have fit through.

A possible idea for visualization...aluminium is somehwat lighter metal, it may provide a bete visualization of the jet channel than steel. Also, what if you would stack very thin steel (or aluminium) plates head-on (so || instead of =), support them by a strong frame to prevent sideway displacement too much and then fire the charge? Could you peel the steel plates like an onion or would the plastic flow weld all plates together? Probably the latter, still worth a try maybe. Could even make a casting of the jet channel perhaps. Easiest for making as positive cast of the jet channel seems firing the charge into a piece of steel tube filled with a low melting lead solder (IIRC, they come down to <100 deg. C.), casting in epoxy or something and melting away the solder again, how cool is that!

[Edited on 12-1-2019 by nitro-genes]

Quote: Originally posted by nitro-genes

The relatively large penetration hole is probably mostly the result of the hemispherical part of the liner (This part produces a slower jet than the conical part of the liner). Having a slight trumpet shape and/or sharp cone and >2 CD headheight/waveshaper above the liner, the charge produces only a very narrow jet channel. Made a 17mm charge this way once, it blew a hole through 5 cm of steel, but the only thing visible was the smallest pinhole trough the steel for which I doubt even a needle could have fit through. [Edited on 12-1-2019 by nitro-genes]

Hmmm...a needle hole like this one?



Made by a 5mm liner going through 3,5mm mild steel rectangular tube. I only packed 150mg penta charge into this one and it still went through.










Bottom side of the tube got a beating too:



[Edited on 12-1-2019 by markx]

Quote: Originally posted by Fulmen

Don't get me wrong, that's good performance. I've drawn some liners myself and it's not as simple as one would think, I've seen my share of split jets and crazy splattering. Just getting a single clean jet is good work. But compared to the professional devices it's pretty poor. I mean, where's the multi-caliber penetration with long standoffs? I haven't seen it so far with anything I've put together either. I've wondered if it's worth the effort to swage the entire cone, i.e. a close-fitting die/mandrel and enough force to press the entire cone plastic. I'll have to borrow a bigger press for anything in my size-range (15-30mm caliber), and I'm low on good tool steel.

I guess our efforts do not amount to such performance as displayed by the cutting edge of the field....still good fun though

How about machining a cone from solid stock instead of press forming/swaging? Machining should create less inconcistancy in the liner than drawing it from a sheet metal form...

Quote: Originally posted by Fulmen

True, but it's not as simple as it sounds. The trick is holding the part, I guess it could be glued to a mandrel. And copper is a PITA to machine. And aluminum just feels wrong when copper is so much better. What's the verdict on brass or bronze?

I know.....I have been dealing with the issue The machining part is ok, one just needs very sharp small steel cutting tools and lots of good cutting oil. Forget about carbide inserts for copper. They bind and gall and ruin the surface. With a small steel cutter and good oil you can get a mirror finish on pure copper. LOCTITE LB 8031 is a rather good all around cutting and threading oil. I've found it to work on most metals and alloys.

If one was to start from a round stock then the stock itself can act as the holder. One finishes the inner surface and then gradually goes about the outer one until the cone tip releases the part. It is a tremendous amount of work though and very likely one just breaks in the last 15%, starts increasing cuts, the part deforms, binds up on the cutter and all goes to hell But it can be done....
Do not know though if it has much of an advantage over a formed liner as far as multicaliber penetration depths go.
With already formed liner the only way is to glue them to mandrels and machine over them. LOCTITE 4062 is a good choice for that purpose. It has extreme wetting capability, instantaneous curing between metal surfaces, it can be released by moderate heat and the residue can be removed by toluene, butyl acetate or xylene based solvents. The cured glue gels up and releases from surfaces very cleanly.
In fact I already machined one mandrel to finish the small liners in lathe after forming, but I wanted to test out if it works at all in such diameters before proceeding to more complicated finishing operations. Seems that there is potential....

[Edited on 13-1-2019 by markx]

The bucket looks like he go through a war zone. Good Mad attempts......

Working on refining the liner geometry a "bit".....


Indicating the support to be dead centered, the rough liner after pressing (0,3mm thickness), the adhesive for fixing the liner to support:





Taking off the high spots with a really tiny cutter until an even surface is achieved:





After a bit of polishing the outer surface can be deemed worthy....also a glimpse at the black oxide coated holder I made for the cony bits to keep them from submitting to the call of the second law of thermodynamics (enthropy being the key word here )




A wee bit of heat helps to get the liner off the support without any troubles:






The arse end of the same support is machined to accomodate the concave image of the liner for a reversed seating and a matching cone in the tailstock shall support the copper while being glued to place:




Seems to turn out OK.....but the troubles began as I attempted to machine the inner surface flat. Seems that the seating was so perfect, the glue does not wick inbetween the surfaces and only holds the outer rim. Two times the liner came loose during machining...I gotta figure out something to rectify this:


I am puzzled....that adhesive is like the devil when it comes to seeping between surfaces, even the tiniest microcracks are filled instantly and completely. And now it fails to the job....

[Edited on 21-1-2019 by markx]

Quote: Originally posted by MineMan

Markx. You read that in “100 year history of shape charges”. They claimed to have accelerated EFPs to 6kms using the X Charge. Although little detail is given. For some reason, the current wave shapers I have seen are not mirror images... A few months ago I saw a very complex waveshaper that was being modeled. It looked like symmetric claws... I can’t find that document anymore... it seems there has been a purge of this technology on the internet. It sucks that I will only know the innovation of 40 years ago... it seems this material is home to so,e of the largest libraries... which are classified??

You are probably right, I remember there were a lot of historic descriptions of events represented in that book.

I know the "clawy" design you are talking about....if I recall correctly it was a novel approach regarding the formation of a large diameter jet that was almost equal to the diameter of the charge. Very complex approach from a technical side.

Old information is not of lesser value to the researcher, in fact I have often found the very opposite of that being true. And really for obvious reasons the contemporary discoveries in that field are not public knowledge nor will they ever be. So it is of little use to feel dissappointment about it
But on a generic level, given the emergence of destructive insanity that rises it's ugly head in the world, I fear that very soon we shall experience a major censorship ban on a great deal of information which we regard as being freely available. It shall happen quietly, gradually, in official denial of the fact and I feel it has already started. This process shall hardly be reversible in our lifetime and that truly is something that we should feel very much dissapointment about.

Quote: Originally posted by markx

I fear that very soon we shall experience a major censorship ban on a great deal of information which we regard as being freely available. It shall happen quietly, gradually, in official denial of the fact and I feel it has already started. This process shall hardly be reversible in our lifetime and that truly is something that we should feel very much dissapointment about.

How can working flexible shaped charge Semtex Razor ?

Quote: Originally posted by specialactivitieSK

How can working flexible shaped charge Semtex Razor ?

Quote: Originally posted by Microtek

To me, that looks more like a copper liner. I would think it is probably just annealed, but it is possible to make shaped charges with liners made from powdered metal such as copper or tungsten. If the powder was bonded in a rubber matrix, it would be possible to make a flexible shaped charge, though it wouldn't be quite as effective as a normal one with a solid liner.

Quote: Originally posted by MineMan

All. See what complex wave shaping is capable of!! https://www.researchgate.net/profile/A_Resnyansky/publicatio... Now my question to you fellow scientist is the paper says aluminum makes the best penetrator for copper because it matches the impedance of the concrete target.... Can someone explain this? I thought penetration was all about, jet length, density and velocity... once again I guesss Newtonian physics is over simplified

Quote: Originally posted by specialactivitieSK

The flexibility. How can work flexible shaped charge without solid liner. What type of liner is used.

Quote: Originally posted by markx

You can try the "x-charge": a classic cone liner with a mirroring cone waveshaper just behind it. The tips virtually connected. The cross section looks like a X shape....hence the designation. It was supposed to have greatly enhanced depth of penetration. For the life of me I can not remember where I read about this design. It was some kind of a document describing the developments of shaped devices in US military structures.... It is way more productive to cast the waveshapers from epoxy. Into molds formed from play dough. One can make numerous specimens in mere minutes. The original mold forming tool may be 3D printed if it is of a particular geometry. X charges and K Charges are not very effective in terms of penetration as compared to a conventional shaped charge at stand off distances of 3-4 calibers. These special shaped charges use less explosive quantity as compared conventional ones. Hence the contribution of total energy to penetration is also less. The moment one brings the waveshaper closer to the liner, tip portion of liner gets vaporised due to high incident angles of detonation wave. Then one needs to go for higher angle cones which naturally have lesser velocity. But then if one looks for large stand off applications, these shorter shaped charges may be of some help. [Edited on 5-3-2019 by markx]

Quote: Originally posted by greenlight

I have been constructing a new 44mm EFP charge over the past weeks to try and punch a hole through a target that has resisted every attempt with a 30mm design. The specs are: ▪Diameter = 44 mm ▪Flyer thickness = 1.5 mm Cu ▪Casing = PVC ▪Charge Weight = 26 g PETN PE (16% inerts) ▪Standoff = 95cm ▪Target = 20mm steel I usually sight the charge with a high powered laser pointer which helps a lot as it is quite difficult to get a direct hit just by eyeing it. Of course the thing decides to shit itself today and makes sure it waits til I am at the test site to do it The target plate is only the size of a dinner plate so it's a small area to hit but I sighted it by eye as best I could before inserting the cap and initiating it. Walked back to ground zero and wow, shock and awe, it hit high. It is quite a decent hit though and quite a wide projectile due to the low head height of the charge. As can be seen by the photos, because it was so close to the edge of the plate it penetrated for a bit and then lost kinetic energy to the side as it took the path of least resistance and slid off over the top of the plate (that part was the top, plate was stuck in ground). You can also see stress fractures in the steel. Also take into account the fact that it would have hit at a 10° angle instead of straight on, and the plate was just hammered into the ground and had some movement. Penetration from what I can record is about 13mm before it started moving laterally. Im sure it would have almost if not fully made it if the hit was direct. Can always try some barrel tamping if not. Guess I will have to step it up to a 50mm and have another crack at it, but first to find another decent laser pointer. [Edited on 15-10-2018 by greenlight] [Edited on 15-10-2018 by greenlight]

Thankyou..
The next variable to be changed was indeed the flyer thickness up to 2mm.
The projectile from that test did hit in one spot with minimal breakup, the other marks are from previous tests.
Unfortunately it hit on the very top and transferred a third of its energy off the damn plate