How Dangerous are 3D Printed Knives?

[@thelumpofdirt6257]

Does anyone else appreciate the irony in wearing a face shield, then throwing the knifes at the ground wearing crocs

[@Draliseth]

I mean, I've watched plenty of I Did A Thing so I'm desensitized to that sort of fate tempting horror.

[@ChainsawFPV]

@@Draliseth I don't kno how he has not lost a toe yet. Lmao!

[@imv2077]

or how the camera man loves to stand behind the target

[@Quifuh]

I'd rather lose a foot than my eyesight.

[@UntrainableWizard]

​@@Quifuh I don't know, think about all those items at the top of your cupboards that you wouldn't be able to reach any more... and you still have your eyes, so they're just mocking you and your shorter stature, now.

[@kernelpickle]

Prison inmates have been stabbing each other with plastic shanks for years, so they're definitely effective weapons. They typically use a toothbrush that's been melted with a lighter, but the number of stabbings in prison, which is probably a majority of stabbings overall, are often done with an improvised plastic weapon. So, yeah, it's no joke--if you're motivated to put holes in someone, it's both easier and more difficult than you'd think.

[@blaise5044]

They often use razor blades attached to each side of a toothbrush too, melted into it so it stays. Makes it super hard to stitch up

[@clydecraft5642]

I imagine breaking the toothbrush just right is an instant shank

[@sarahmellinger3335]

@@blaise5044 lock in a sock is another prison classic

[@kkkaTheIdiot]

​@@sarahmellinger3335 and it's variant soap in the sock

[@rivencraft1734]

​@@blaise5044the difficulty of stitching a hole has very little to do with the thing that made the hole. Bullet holes are a lot tougher than anything a razor will make and they stitch those up fine.

[@orangeinferno]

She truly is the michael reeves of 3d printing

[@Envi_is_lost]

I saw a 3d printer ad as soon as I read that

[@viggo_wiberg]

@@Envi_is_lostdidn’t ask

[@johnmadden9613]

same energy. fucking hilarious honestly. "women in stem, baby!"

[@timboles9480]

Not quite as bad but definitely same energy

[@STOPSYPHER]

@@Envi_is_lost What?

[@cyphre]

Ballistic gel is one of those materials which is basically only useful as a metric for comparison. Usually tissue expansion due to the body being made mostly of water. Not quite the best for testing sharp objects. Should check Joerg Sprave's tests for sharp things!

[@rickoshea8138]

It has high friction, which is not present with the original "original" you are trying to analog.

[@vinny142]

@@rickoshea8138 Indeed. It's also called Ballistics Gel for a reason, it behaves like body would when shot, not when stabbed.

[@unknown-ql1fk]

​@@vinny142even this is a misnomer, ballistic gel is a tool to compare the function of small arms rounds to each other, it has nothing to do with simulating a human. The FBI had all sorts of data of gun shots on people but could not compare a, say a .380acp +p vs a 9mm normal pressure to get a definitive result so they made a test media to compare, not simulate humans

[@OriginalAirsoftGasser]

@@vinny142 No it doesn't, it's designed as a constant meaning that it gives a constant result for ballistics, nothing to do with simulating human tissue, Emily just doesn't understand and is working off internet myth which idiots have posted.

[@UntrainableWizard]

I have a legitimate question- but don't they often use real bodies for testing this stuff? I know if sounds dumb to ask that, but I know they use real bodies in some places to test explosives, so I'm curious if it's done with firearms as well. (obviously I mean dead bodies donated to "science", which... I mean... Imagine thinking your bodies going to be useful for something important just to be given the equivalent treatment of an action man with a firecracker taped to it and treated like the toys that belong to Sid in Toy Story.)

[@campbellwalls6720]

Ballistics gel also has a tendency to grip when things pass through it so it's not really conducive to how knives or arrows actually work because flesh is slippery once penetrated which would make a knife or arrow go deeper with less force. Almost anything with a point on it can be used as a lethal weapon. If you strike at an absolutely perfect angle you can penetrate flesh with a plastic bendy straw.

[@reaganharder1480]

in terms of actual danger with a stabby thing, it may be good to test it with a layer of fabric in between, as unless you make a habit of walking around nude, anyone stabbing you will likely be stabbing you through a shirt, and even such basic armor as a cotton t-shirt can have a surprising effectiveness against sharp weapons.

[@tonnentonie2767]

It would be really cool if our body would behave like ballistic gel when stabbed

[@xthereon754]

​@tonnentonie2767 Ah yes, jiggle physics

[@UntrainableWizard]

A tendency to grip, you say? And... where might one get ballistic gel? For uh... ballistic tests, of course...

[@UntrainableWizard]

​@@xthereon754 You gotta get the Japanese, or Indie ballistic gels for that. xD

[@LaurentMaitreK]

Fun fact, most ceramic knife makers do put metal powder in the ceramic to have it trigger the metal detectors at airports and events….

[@johnschneider931]

Funner ? Fact . Tara? No spelled... Terra? hertz scanners dectect hard shapes, no metal needed

[@slowazzd2165]

​@@johnschneider931a lot of places still just rely on metal detectors and manual checks though, those machines are expensive in comparison

[@magebear7]

At 3:48, I quickly saw "perfect for multiple cats" on the cardboard box with no context. This led me to believe that the selling point for the fridge (or whatever came in the box) was that its box was perfect for multiple cats to play in. So I rewound and found the context, and am now fully convinced this is the intended reading.

[@FasutonemuMyoji]

It's a robot litter box, but sure, the box it is packed in is also a cat-toy, as all shipping boxes are!

[@berndbeispielmensch]

This is interesting, funny, and kind of scary, all at the same time. Next level: a robot to pentrates the knife with repeatable force into the gel. Also, some slow motion might be cool; maybe a colab with @theslowmoguys.

[@pawliemorph3941]

I thought this was a fun video and I loved the apron and I'm vicariously sad the amogus mold didnt work out. The ballistic gel was super cool, though, I didn't think it would be so dense. Theres a company called Black Triangle that makes pointy things out of G10 material that is used a lot in knife handles. Kind of a last ditch stabby boi vs something that will cut or slash. I'm kinda interested if YT will throttle this kind of video too like they do the pyew pyews

[@hulk239239]

Cold Steel also make their Nightshade series of Zytel plastic knives

[@thoughtsaboutrodger2956]

Truly the peak of what a STEM major can achieve

[@suzyamerica4679]

Nope, that's when we can 3D print our own sewing machine accessories and cookware 😅

[@DataCab1e]

Face shield + crocs = peak PPE

[@catkook543]

i wouldn't be too concerned about criminals 3D printing bladed weapons, even if the blades are potentially dangerous. For several reasons. - Criminals can make dangerous weapons with a lot less, thats how prisoners have shanks. - If they have access to a 3D printer, they're likely capable of getting more potent weapons from sources outside of that 3D printer - Any attempts to regulate criminals from making bladed weapons with 3D printers would hurt normal people a million times more then it would for any criminal

[@alexjshank]

I am absolutely amazed that no one was accidentally stabbed by a rebounding knife during filming.

[@andresmartinezramos7513]

What had me on edge was her pushing the knife into the gel with her other hand very close

[@BasedBidoof]

I love my 3d printed pews. Always gets attention at the ranges :D

[@InvertFPV]

Me when I roll up to the range with a transparent Polycarbonate upper. Always gets the right kind of looks from the RSO's.

[@ArchOfWinter]

If that Japanese knife maker can make kitchen worthy knives out of chocolate, paper, blood, glue, or whatever, he did a lot, 3D printed knives will work better than those. The more important question is how well do they retain their edges.

[@viscache1]

If you happen to have some furnace duct metal you can epoxy it to the side and sharpen that metal leading edge. I did this to cover for a hunting knife one year because I lost my $220 Kershaw customer folder skinner. I figured I would find it so I cut a knife from a sheet of nylon 1/2” in the shape of a knife, ‘sharpened’ it and epoxied/riveted a thin sheet of waste sheet metal from my metals pile (old furnace tear out). I used it for two years, sharpened it on rocks until it just wore too much away…never did find my favorite knife and was too cheap to replace it…call it farmer economics.

[@davidy22]

It's heat moldable plastics, they'll cut one thing and blunt immediately

[@Finchyboi14470]

This is the kind of wholesome, 3D printing centered relationship I am striving for

[@nemtudom5074]

0:10 Emily truly is the best wifi

[@haugstadianer]

Ballistic gel does not act the same with knifes as bullets, that is why it has the word ballistic in the name. The friction between the gel and the side of the knife is too high. For testing knifes a cabbage would be a better approximation to human flesh.

[@sean5278]

In tacti-cool circles we use bone in roasts. A small locally owned store will sometimes hook you up with rotten meat for free. Oh hey it's the gun psycho asking for rotten meat again.

[@lordisaac]

some of those stabbing the side of the block were making me nervous when you had your hand on top of it and only stabbing a few inches away from your hand and arm...

[@jacksonc8243]

Fr. Too many accidents happen pushing stuff towards another hand you thought was safe

[@vinylwubs6987]

This whole thing seemed kinda unsafe, the casual attitude, comic sans and crocs didn’t exactly scream “person who can handle a bayonet knife”

[@danieldean7504]

I’m a Blacksmith and my apprentice and I like to leave random crewmate drawings around the shop for each other to find.

[@hiddenloaf2302]

You can 3D print a whole lot more than just sharp pointy things nowadays. Definitely a cool video that tests some uncommon designs.

[@RKNGL]

British police shaking and screaming right now.

[@evanf1443]

For future reference: If a blade doesn’t have a cross guard of some sort, anchor a finger or your thumb (whichever is applicable) underneath the handle when stabbing so your hand can’t slip towards the blade and slice open.

[@heroslippy6666]

Prisoners make shanks out of anything, even plastic.

[@MojitoMouse]

The thing about 3D printed knives.... If it's sharp and strong enough to enter the body, but brittle enough to shatter, it could do some SERIOUS damage, now in stead of a stab wound with a knife in it, you have a stab wound with multiple small sharp pieces of plastic in it! XD

[@Hunter-lm7wo]

add on that, It would be invisible to x-rays, so the arrow tip is even more terrifying

[@MojitoMouse]

@@Hunter-lm7wo Huh, did not know that! :O

[@foxlive420yes9]

OK I’ve never seen this person in my life why do I love the fact that she’s going with the kitchen joke

[@Notification-i7o]

The knifes in the corner 😭 0:34

[@PurpleBox89]

"Shoulda been a doctor" underrated line there. The actual hint of regret in his voice.

[@roro6064]

First time seeing the channel and I loved it. The intro story was so cool and I love how it’s just y’all hanging out making this video. So tired of these channels with a whole production team and a fake personality

[@oldsalty3d122]

First time I've watched one of your videos, you all look like you had a lot of fun making it. Thanks, I found it very entertaining. 😁

[@goldenarri]

I love this channel so much

[@geek_industries]

I saw you made a lightsaber. What did you use for the blade? Wanting to start to make one as the official ones are too pricy and then I can improve finishing techniques. Loved the throwing stars.

[@graealex]

For a light saber, you need an emitter matrix, a power cell and a crystal, the latter which will also determine the light saber's color.

[@risaistalri1675]

That type of gel is mostly for measuring bullet velocity and power.

[@viscache1]

You can make a pointy object out of anything. And it will work at least once. To for a life of crime…not great…. But for a one off….perfect. Thanks for a great video… My only problem is that You Tube did not put a subscribe button on you channel!?!?!? You might want to check into this because I would have subscribed if there had been a way to do so. PS: PLEASE Be CAREFUL when stabbing directly when using a knife. The primary injury is for the hand to slip forward onto the blade…yes…even if there is a hilt to block that from happening. I worked in an ER and this is the most common knife injury…NOT the pointy end.

[@andrewut7ya511]

If you want a reeealy strong printed knoife, make print it flat on the side of the blade and alternate line direction [0,90] every other layer will run lines from the tip of the blade to the handle then the other layers crosshatch with lines across to lock everything in place.

[@capnskustomworks]

As thrilled as I was with the awesome experimentation, I must lodge a complaint that ye got me really excited for sewing at first… 😆 Those turned out excellent, and way more durable than I would’ve guessed! I wish the huge mold worked!!! The little ones were still adorable, though! (And stabbable! Ha!)

[@DarkTrapStudio]

You don't need to sand it more, you need finner sanding (finish like at 10000), Ive seen a guy made razor sharp knife out of a pasta on youtube, more than most chef chef knive Ive seen in the restaurants Ive worked.

[@AdityaMehendale]

Now imagine archeologists from 4000 AFSM wondering what resin arrowheads are doing around AmongUs-shaped fossils..

[@DDVgamingpros]

In case anyone asks: FBI rated Ballistics gel is meant for ballistics testing of FIREARMS. its designed to test how bullets penetrate the ballistic gel, their trajectory after hitting it, how far bullets would penetrate, etc. It is NOT designed to test the lethality of melee weapons let alone improvised melee weapons. if you want to test melee weapons or any type of melee object try pig, or human gel molds of dummys with human body parts and blood in it. This would give a better idea of how effective melee weapons would be. the human like gel molds are generally softer and closer simulate human flesh/skin and thus produce more accurate lacerations (cutting) marks on them for knife wounds. ballistic gel blocks are designed to measure ballistics ie firearm bullet wounds.

[@jeffthorson625]

you can buy plastic knives for the kitchen i own one it is specific for cutting lettuce to concept behind it is that lettuce touching metal makes it brown

[@S-G-zm3uu]

Im saving this video for my trip to england

[@greenman360]

I mean in theory the pearl clutchers should be way more afraid of 3D printed knives, because they can be all plastic, no metal required at all. Meaning they can find their way into a lot of restricted areas...

[@karlmckinnell2635]

I could sense the fear the cat was experiencing at that moment 😂.

[@realaledrinker3733]

Just an expensive prison shank could have just sharpened the end of a toothbrush

[@kksmith244]

I was surprised how strong my hidden blade pieces were when you print them horizontal instead of vertical like yours were.

[@PokuBit]

people in prison use a sharpened back end of a toothbrush as a shank, that answers "does plastic work as a knife"

[@kingmart2746]

This woman is a real chad I've never seen a woman take the phrase "go to the kitchen" as a joke

[@ButterMilkPancakes]

Ah yes let me go down to the 3d printing store to get my dangerous 3d printed knife instead of... buying a real knife

[@m4rt_]

You don't even need a 3D printer to make a deadly weapon. You just need some sticks and stones. It worked for hunting back in the stone age.

[@squash9189]

“It wasn’t enough to tell me if the knives were dangerous or not” i’m not the only one expecting her to test on a human, right?

[@ShoreFell]

I love that she basically just taught anyone with a 3D printer “here is how to make a weapon. Have fun!” and I love it 😂

[@ScytheNoire]

ASA is great for making weapons. It's very tough, strong, rigid, and UV resistant.

[@autorobot8240]

This tickles my gen-z brain lol. It’s crazy to me that y’all are only a couple years older than me, keep up the engineering!

[@Martarts]

This can't be a good idea 😂 let's see how it goes lmao

[@g1g3l]

You most likely made 3d printers illegal in UK now. Or only legal to own only if: you have a 3D printing licence, you register the printer, you're under constant supervision and get weekly checkups from.

[@enderhayes4211]

the best part of the resin printed pointy things is if you don't wash them before using them they also deal poison damage :D

[@Pabloisradical]

So there is a market for non Ferris self defense sharp objects. I’m super surprised there were no gloves seen at all in this video. Also you should’ve used a side of pork belly to have a better control medium.

[@pwhite2579]

steel is way heavier than plastic so the plastic ones won't throw well. You need both sharp + tough + heavy.

[@superslimanoniem4712]

Hmm... Maybe low infill, then fill with a resin mixed with some kind of metal powder to add density?

[@pwhite2579]

@@superslimanoniem4712 yes, that would be a start but also lots of experiments. Print with ABS not PLA, maybe... ABS is much tougher.

[@ILoveTinfoilHats]

"Lubing the inside of the amongus" is not a sentence I ever want to hear again 1:11

[@Xarl-VIII]

For ballistic gel its best to leave it for a week to firm up

[@squigglysailor6261]

This channel is underrated. She should be at least at like a mil subscribers

[@GusCraft460]

I mean, you can make a knife by literally banging two rocks together, basic tools can sharpen steel scraps into blades, and every house has a set of kitchen knives. There were tens of thousands of years where everyone carried a knife with them at all times.

[@homeopathicfossil-fuels4789]

Back when I was into pellet guns you could buy these pellets that had a hollow point and a plastic tip glued into the hollow point (so it wasnt hollow anymore I dont know an english term for it but the german one is spitzer IIRC) it was designed for bird hunting apparently, it would strike the bird, discarding the plastic tip for increased penetration. Also nurses practice injection techniques on oranges around here, because the skin and layers below apparently break in a similar manner. These are my completely unsolicited and probably annoying anecdotes and suggestions. Also your cat = cute.

[@andybrown4284]

Since a shiv is often melted from a donor object, something thin and pointy like a fairbairn sykes commando knife would be a better choice for a 3d printed stabby. With a lighter and some sandpaper you can make a blade out of a credit card sharp enough to shave with.

[@CatArmyGeneral]

Can't stop the signal!

[@vortecmacs]

The Ides of March on the Amongus was brutal.

[@lyn10gaming]

5:15 "Yeet"

[@NullAndVoided]

After working a few decades in kitchens I can promise you that a knife will slip into a piece of meat with minimal effort. (It’s actually kinda scary how easy it really is) Ballistic gel is not an ideal medium to test edged weapons.

[@whirlpool9353]

I have a bambu lab p1s. Cant wait to do some wholesome things with it :)

[@zottestudios]

You should print the blade laying on its side so the layer grain runs length-wise. This'll keep the blade from breaking off into the target

[@stephenadams8712]

Funny you bring up the Geneva Convention when making the Among Us mold as the game was in breach for using the red cross logo outside it's intended use

[@mikoajlewicki9512]

"Remember kids knives are good for shallow cuts, but if you need deep penetretion you should use flat screwdriver. untill we meet again..."

[@ArchGeek]

“Women in STEM” had me rolling. Glad y’all can see the humor in that ridiculous campaign.

[@brettleisy356]

sharpening methods improvements... angle of cutting edge will depend on what you are using it for, 17-20 degrees is typical in American steels, 15 for Japanese steels working your way to a finer and finer grit is important as it will help create less jaggedness and less drag along the edge. sharpen or at least polishing refinements (the medium to high grits) should be done at a perpendicular direction of motion to the blade. this create the micro serrations needed to cut/slice things.

[@ItachiUchiha-gf4fz]

I couldn’t believe it, you sound like exactly Akidearest. The way you talk, how you sound and editing itself. You two basically identical.

[@Runedragonx]

There's this magical thing called a rondel dagger, a grip just long enough to fit your hand between two wide plates and a long triangular spike. It was designed in the Medieval Era specifically to punch through chainmail.

[@davidoberle9023]

Please do 3D printed bullets next.

[@deemayday4517]

There wasn't much point in printing out arrowheads since you're shooting it out of a compound bow. You could probably print a cube head, and it would cause a similar amount of damage when shot. It won't fly well, but you guys are firing from point-blank range, so that doesn't matter.

[@Blakrex]

Whenever someone asks the question "could X be dangerous/used as a weapon?" I always recall a fond memory. When I was a child of only 9 years old I once challenged my older (much larger) brother to the right to sit on the "nice" chair. After calling him a "fatty" he was roused from the chair where he screamed "I'm going to kill you!". But my confidence was high due to a secret weapon I had in my hand. It was a paint pop sucker. He ran at me with blood lust in his eyes, I feinted a throw of the sucker and he hesitated for a moment then immediately charged. I threw the sucker at him and ran. I heard a significant amount of painful screaming as I hid in the bathroom with the door locked. When I I finally mustered the courage to look out the door I saw my grandmother treating a very bloody wound on my brothers hand. A trip to the hospital later along with 9 stiches I announced myself the victor and concluded that yes; even a sucker can be used as a potentially deadly weapon.

[@3DJapan]

I designed and printed some knives with resin. They're able to cut a sheet of paper but not much good as a box cutter.

[@jarnMod]

That Among us jello is the best thing I've seen this month.

[@martinhaile853]

You should 3D print a gun

[@ArchDeusAirsoftNC]

🗿

[@OhiotitanVr]

Your a menace to society

[@freddieviggers4241]

i can indeed confirm the fact 3D printed knifes are sharp because i have sold them at a school before, the results were not what you´d expect.

[@ser_igel]

i'm sorry emily the engineer that's the first video on you channel i've seen but please (please!) use cut protection gloves, that's important if you want to keep your hands in working condition after testing knives they're pretty cheap ($30 for a pair of decent ones, $100 for good ones), and while they might not seem worthy, the time you spend recovering from an easily avoidable injury will convince you otherwise unless someone else convinces you first

[@noahlathrop4111]

Sanding something is how you sharpen it. You can sharpen a tooth brush by sanding it with concrete. I definitely recommend wet concrete. The Throwing knives aren't heavy enough to pierce

[@nicolewilliams6368]

Shiv or shank is slang for a improvised weapon made by prison inmates. They use just about anything including sharpened plastic to make these things. I can't think that a 3D printed knife would be less effective than a shiv.

[@myname-mz3lo]

if you paint the blade with a few layers of epoxy you can get it crazy sharp

[@bludragon1328]

Her humor is top notch ngl

[@jeffthorson625]

you can buy plastic knives for the kitchen i own one it is specific for cutting

[@Donggers]

Plastic projectiles and fragments are actually a war crime. Since metal detectors are useless the wounded soldier would suffer needlessly.

[@Lizlodude]

6:33 Yay safety third! 😅

[@youtubecommenter2527]

For the knives you should have printed a knife design that isn't hilariously bad. Print one that's shaped like an actual combat knife.

[@sovietrook7425]

The thing about 3D printing stuff like knives, is that it is probably easier and better to just get some scrap metal instead. Still, really… really interesting.

[@potteryjoe]

A guy I used to work with asked if I'd print a knife for his sister to take on an airplane. I asked how badly he wanted to get her arrested. Didn't print it for him.

[@Flaspect_]

Litter robot box... very scary.

[@Tridrip]

i thought i recognized you from somewhere, i thought it was a jackpop video but then i remembered that my brain doesn't work and i would probably recognize anyone as someone from another video

[@LocalDiscordCatgirl]

Regarding ballistics gel: BG is a fantastic medium for analysing the damage caused by bullets. The forces resisting a bullet in BG are identical enough to the forces resisting a bullet in human tissue. However BG is a poor medium to demonstrate damage caused by cutting or stabbing, especially compared to the forces in human tissue that are encountered by a blade or pointy pokey stabbey thing. A blade does *work* by cutting through the fibres. It does this well, as a set of inclined blades, a knife or arrowhead is a simple machine. Additionally, upon coming into contact with a blood vessel, a blade becomes lubricated, while a bullet is resisted by the flow. You can shoot a piece of kevlar body armor with a pistol and the bullet will not penetrate. That same sheet of kevlar will not stop a broadhead because it cuts through the kevlar fibres. A bullet tries to push apart the fibre weave, much like it needs to push apart body tissues. A knife or blade pushes through by cutting the fibres and removing the resistance. There’s a research paper that concludes that the only acceptably accurate test medium for the effects of bladed weapons is a *live* or *very* freshly deceased animal, because nothing else acts the same way as a body.

[@firstpersonforge]

Have you considered silicone caulk for keeping multi part mouls leak proof? I don't want to tell you your business as I'm not a 3d printer but man that's a lotta leaks.

[@Greendawn-di3dl]

"Disign is my pashun" proceeds to show an amongus mold that leaked immediately. Great work otherwise fun video!