Plane Crashed After 3D-Printed Part Collapsed (bbc.com) 93
A light aircraft crashed in Gloucestershire after a 3D-printed plastic air-induction elbow softened from engine heat and collapsed, cutting power during final approach and causing the plane to undershoot the runway. Investigators say the part was made from "inappropriate material" and safety actions will be taken in the future regarding 3D printed parts. The BBC reports: Following an "uneventful local flight", the AAIB report said the pilot advanced the throttle on the final approach to the runway, and realized the engine had suffered a complete loss of power. "He managed to fly over a road and a line of bushes on the airfield boundary, but landed short and struck the instrument landing system before coming to rest at the side of the structure," the report read.
It was revealed the part had been installed during a modification to the fuel system and collapsed due to its 3D-printed plastic material softening when exposed to heat from the engine. The Light Aircraft Association (LAA) said it now intends to take safety actions in response to the accident, including a "LAA Alert" regarding the use of 3D-printed parts that will be sent to inspectors.
It was revealed the part had been installed during a modification to the fuel system and collapsed due to its 3D-printed plastic material softening when exposed to heat from the engine. The Light Aircraft Association (LAA) said it now intends to take safety actions in response to the accident, including a "LAA Alert" regarding the use of 3D-printed parts that will be sent to inspectors.
It seemed like a good idea (Score:2)
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Re:seemed like a good idea at the time (Score:3, Insightful)
Qualified to work at Boeing.
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Did they use PLA instead of carbon fiber 12 or something? LOL
Re: It seemed like a good idea (Score:3)
Carbon fiber filament might not have been a good idea either. What you're really looking for is a higher melting point. 3d printed carbon fiber is typically just a blend of nylon and small bits of fiber made of carbon. That is not the same as material made from long threads of bonded fibers. You're looking at a melting point of around 600f, tops, and it will probably begin warping at even lower temperatures. It might do in a pinch if you use thick walls, but unless you're stuck in the Andes mountains with a
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What they mean by "carbon fibre 12" is probably CF-filled PA12, a nylon. PA12 CF has a maximum working temperature up to 170C, vs. (for the two most common filaments) ~80C for PETG and ~60C for PLA.
The thing is, everyone who has been printing for more than a couple days should be familiar with all of this. It's honestly shocking that they'd use a material that doesn't tolerate the heat in question. Did they not know how hot it was going to be? Was there a chain of miscommunication, where the person who d
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ED: Sorry, didn't read enough into your post. But the TL/DR is: know what stresses and temperatures your part will be exposed to, and make sure the part can actually withstand them. And if you can't do it directly with plastic, then either use something like Virtual Foundry Filamet + sintering, or print a mould and cast it.
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Will to be fair if it had been 3d printed out of Peak or a number of other engineering filaments then no it wouldn't. Believe it or not there are consumer printers that can print this high temperature filaments. Obviously be didn't use over of them. In less critical applications people have been 3d printing and air box parts for cars for years. And no they don't melt either. Engines usually run well below 270 C. But this is not an airplane obviously.
Re: It seemed like a good idea (Score:2)
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PPS is a fun one. Maximum service temperature of 220-240C, yet melts at 280C and you can print it at 300C (doesn't require a super-high-temperature printer). You can literally cast some pewter alloys directly in it in a hot oven. :) Also does not dissolve in any known substance below 200C.
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Re: but it dried! (Score:2)
That's one of the things that the pedantic in me is getting a cringe about. Hot glue and other melted things don't usually 'dry'. They either simpl y harden because the temperature is below their melting point or they cure due to a chemical reaction. Even concrete does not harden by drying, the wetness simply enables the chemical reaction to occur.
In the case of that plane modification, if they did use something that cures, it -might- have helped. But please, please, do not fix or modify critical components
Re: No kidding (Score:3)
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Yeah in this video about filaments [youtu.be] he describes it as a viable alternative to steel but... $700/kg, 400C print temp, 140C heated print chamber and it's not even the worst, apparently that's TPI/Kapton
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You can do PPS at 300C and it has nearly as high of a working temperature. From a factory in China I've bought filament from before, you can order it (with a minimum order of like 60kg, mind you) for like $15/kg.
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100% yes. It's called 3D print it in something with a low melting temperature. (Maybe PLA.) Then, pour ceramic around it. And use it to cast an actual fucking metal part. LOL.
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100% yes. It's called 3D print it in something with a low melting temperature. (Maybe PLA.) Then, pour ceramic around it. And use it to cast an actual fucking metal part. LOL.
Came to say the same. And depending on the geometry of the part, you might not even need ceramic. Some people also do "lost PLA" sand-casting.
Re: No kidding (Score:3)
Or, 3D print a prototype for fit and a ground test, then send your file out to get a metal sintered version from a print service bureau.
In amateur rocketry, there are constant questions about heat resistance of both 3D printing filaments and epoxy. As amateurs, there's kind of a 'try it and see' mentality. But good Lord, you're not RIDING in the thing!
FAFO!
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PEKK, PEEK or ULTEM are what I'd do if I need high temperature stuff. PPS-CF comes close, as I bought my Bambu X1E for that stuff. Tullumer stuff looks promising as well.
For stuff that sits in a car and likely won't warp in the sun, I just go ABS or ASA.
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For stuff that sits in a car and likely won't warp in the sun, I just go ABS or ASA.
Either print in a well ventilated garage or get an activated carbon filter. ABS gives off toxic fumes, so take care. Otherwise I think it's a bit of an underrated plastic.
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The fumes thing is overrated - typical measured levels in a room printing ABS are in the ppb range, whereas the PELs are in the ppm range. That said, don't sit right next to your printer for a long time while it's printing if you don't want to breathe a lot of styrene.
Main annoying thing is that ABS is hard to print. I mean, it's far from the hardest, that'd be something like polypropylene or whatnot - but vs. say PLA and PETG, there's a learning curve. Big thick ABS cantilevers and the like can accumula
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Slant 3D has some good tips for printing, including standoffs part of the main model that print with it, and are only touching the model at relatively small places (around the diameter of .2mm.)
Having an enclosed chamber heater is a big help. I ponied up for the Bambu X1E, which is like the Bambu X1C except with a chamber heater, Ethernet, and $1000 higher in price, mainly because it could handle ABS with ease. The Bambu H2D also has been a solid performer.
From there, I use ABS support material at interfa
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Early on, I was overdoing chamber heating, and later discovered that was part of my problem. A blanket and a duvet can get a P1S's chamber over 70C. But if you do that, in my experience, like half an hour or so into the print you'll get heat creep problems and the filament will split & the extruder will just dance around in the air as though it were clogged (though maybe my filament was just garbage... it certainly was *wound* terribly). I ended up using a meat thermometer stuck in through one of the
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The fumes thing is overrated - typical measured levels in a room printing ABS are in the ppb range
Fair enough. I've not got any measuring kit and the printer I used most for that is not enclosed, so I erred on the side of caution.
Main annoying thing is that ABS is hard to print. I mean, it's far from the hardest, that'd be something like polypropylene or whatnot - but vs. say PLA and PETG, there's a learning curve.
I never had thaaat much problem, but I was printing my own parts, so designing in part for pr
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I'm using a Bambu X1E (one of two Bambu printer models that cannot be ordered online), a H2D, and soon a H2C. The filtration system is a lot better than the X1 Carbon, and I also have a secondary air purifier system by it. From the air quality meters I have, with the filtration I'm using, it is in safe limits.
You are right about warping. The H-series has chamber heaters, and the X1E also has that. This combined with an enclosed volume greatly helps with warping, to the point where I've done some obnoxio
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That you can print with "many" consumer printers, Polycarbonate would be a decent choice. Glass transition is around 147 (296), and you can print it at a consumer level.
Alternatively, print it out of PLA, dunk it in plaster, and burn out the PLA. Then cast with an actual metal like aluminum (search for "PLA lost casting" on YouTube).
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Two samples from the air induction elbow were subjected to testing, using a heat-flux differential scanning calorimeter, to determine their glass transition temperature. The measured glass transition temperature for the first sample was 52.8C, and 54.0C for the second sample.
With a Tg of around 54C this sounds like it was PLA. It was also missing the aluminium liner that's supposed to be fitted inside the normal epoxy+glass fibre version of the part.
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Jesus. PLA has *no business whatsoever* being *anywhere* on a plane. Even in the cabin. It can melt in a hot car on a sunny day. It's hard but brittle. It's not entirely water-stable. It's fine to make a *model* of a plane, but making actual plane parts out of it? That's insane.
For any non-printers in here: PLA is "corn plastic". You know those compostable grocery bags? Those are mainly PLA , plus some PBAT (another biodegradable polymer, added to make it flexible). Imagine a rigid version of those b
Where did it come from. (Score:2)
If in the supply chain how common are 3d printed parts now for things like plane, autos, and even house hold repair?
Re:Where did it come from. (Score:5, Informative)
He bought it from a vendor at an airshow.
So either a counterfeit part, or some yahoos prototype that got sold off without proper testing.
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It's in the article:
The Cozy Mk IV light aircraft was destroyed after its plastic air induction elbow, bought at an air show in North America, collapsed.
Hecho en EE. UU., baby!
Re: Where did it come from. (Score:2)
Sorry, you're now BANNED FROM /. for the crime of reading TFA!
Re:Where did it come from. (Score:5, Informative)
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This. There are some experimental aircraft that people have, where stuff like 3D printing parts is allowed, but the FAA rep is going to want a lot of documentation on the part and computed/theoretical loads on that part before he gives it a pass.
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Aviation sounds like an authoritarian's dream hobby. Up to its eyebrows in regulation, oversight, and general ass kissing / brown nosing to curry favor.
The latter exists anywhere there is the former, but there are good and obvious reasons why aircraft should have to be highly regulated.
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Aviation sounds like an authoritarian's dream hobby. Up to its eyebrows in regulation, oversight, and general ass kissing / brown nosing to curry favor.
The latter exists anywhere there is the former, but there are good and obvious reasons why aircraft should have to be highly regulated.
Unless they weigh less than 254 pounds: https://en.wikipedia.org/wiki/... [wikipedia.org]
It's kinda cool that a person can bolt something together and fly it legally without ANY certification or instruction. I mean, I'm not going to try it myself, and I don't necessarily want an uncertified aircraft to fly over my house, but it's still cool that there's a carve-out in the regulation so that people are *allowed* to do it.
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Aviation has a lot of rules, but it's not for pointless reasons. When things go wrong in aviation, they tend to go very wrong, and you sent some big heavy mass carrying hundreds of people travelling at many hundreds of kph crashing into a building.
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Re: Where did it come from. (Score:1)
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an aquantance made one from PLA ... ... WHY?
There's literally no reason you shouldn't at least use PETG. PETG is even *easier* to print, and *cheaper* than PLA. Was this long ago, when PLA still had a stranglehold on the market?
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I can't speak for Europe / England and their repair laws, but everything in America is required to be approved by the FAA for use in aviation
He bought it at an airshow in America.
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In theory, you are correct.
However, in practice, you are completely wrong. Uncertified parts are everywhere and in the 70s/80s, a huge scandal arose because counterfeit parts were found all the way into Air Force One - the aircraft part supply chain was full of counterfeit or uncertified components th
Re:Where did it come from. (Score:5, Informative)
https://www.pilotmix.com/cozy-... [pilotmix.com]
For context for those not familiar with experimental/homebuilt aircraft. You can pretty much use anything off the shelf or custom. 3D printed parts (either self-sourced or purchased from dedicated vendors) are probably not uncommon at this point in time, depending on what you are using them for. Certified aircraft do not have this degree of latitude in terms of part sourcing and DIY work.
Now to the question about whether the owner made/installed the part, or it was sourced through the parts chain:
https://www.bbc.com/news/artic... [bbc.com]
"The Cozy Mk IV light aircraft was destroyed after its plastic air induction elbow, bought at an air show in North America, collapsed."
That sentence implies that the air induction elbow was purchased at an air show.
Reviewing the accident report ( https://www.gov.uk/aaib-report... [www.gov.uk] ), we get the following:
"The aircraft owner who installed the modified fuel system stated that the 3D-printed induction elbow was purchased in the USA at an airshow, and he understood from the vendor that it was printed from CF-ABS (carbon fibre â" acrylonitrile butadiene styrene) filament material, with a glass transition temperature3 of 105ÂC.
An alternative construction method for the air induction elbow, shown in the Cozy Mk IV plans, is a lamination of four layers of bi-directional glassfibre cloth with epoxy resin. The epoxy resin specified for the laminate has a glass transition temperature of 84ÂC, after the finished part has been post-cured. The aircraft owner stated that as the glass transition temperature listed for the CF-ABS material was higher than the epoxy resin, he was satisfied the component was fit for use in this application when it was installed.
A review of the design of the laminated induction elbow in the Cozy Mk IV plans showed that it featured a section of thin-walled aluminium tube at the inlet end of the elbow, where the air filter is attached. The aluminium tube provides a degree of temperature-insensitive structural support for the inlet end of the elbow. The 3D-printed induction elbow on G-BYLZ did not include a similar section of aluminium tube at the inlet end."
So apparently purchased through a 3rd party vendor, the owner installed according to an existing design variation (and got approval from regulatory oversight to do so), but apparently the 3d printed part installed did not meet the requirements for temperature resistance as compared to the glass-fiber/epoxy part specified in the plans, possibly due to the lack of that aluminum tube.
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Also, under testing, the plastic melted at *HALF* the glass transition temperature of what he thought he bought.
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Well, "half" is relative when it comes to temperature...
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I'd love to see someone try to 3d print with a filament that melts at 162K. Where do you even buy xenon filament? ;)
"Moron takes dumb shortcut causing plane crash." (Score:1)
I simplified the story for ya.
Re: "Moron takes dumb shortcut causing plane crash (Score:1)
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Ban 3D morons.
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Sad thing we are already having states pushing to do so. Look at the Flashforge debacle.
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No, try "sucker bought what he thought was a functional part that wasn't".
The material was apparently NOT CF-ABS, and wasn't properly constructed.
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Yep, that nicely sums it up.
um (Score:1)
Not a home-printed part (Score:2)
From the linked article: "The Cozy Mk IV light aircraft was destroyed after its plastic air induction elbow, bought at an air show in North America, collapsed."
Re:Not a home-printed part (Score:5, Insightful)
Actually, I suppose the subject should be something like: "not printed by the pilot". Who knows how reputable the company/person was from which he bought the part... and what their supply chain looked like. But, given the information to hand, there's no reason to believe that the pilot had any knowledge of any possible problem with the part.
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Stupid ideas know no race,sex or economical class, they can and will happen to anyone and everyone, and hopefully they will survive it, and if they don't, well, the darwin awards could always use a new participant.
From thieves that think it's a good idea to try to steal the steel beams holding the ceiling to billionaires in a tin can that think they're above the laws of physics, the game is open to everyone.
what a moron (Score:2)
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A part they bought at an airshow?
Did they print it out of pla for peek? (Score:2)
3D printing wasn't the problem (Score:2)
The problem was using a cheap substitute part. I'm guessing an injection molded ABS part would also have failed in that scenario.
CF-ABS is NOT like fiberglass at all. The CF is chopped into fine bits. They lend some stiffness at room temperature but not strength to the part. Certainly the carbon fiber bits don't lend any heat resistance.
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It adds stiffness and some creep resistance. It usually adds a bit of strength, but it's not like epoxy/fibre composites where the majority of strength comes from the fibres. It's A bit more strength, maybe 50% depending on the formulation and part, but often lower. But also, it depends on if you mean yield or ultimate strength.
It's also a good way of trading toughness and stiffness and yield strength. PETG is incredibly tough, not hugely stiff and moderately in ultimate tensile strength. But the toughness
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It's pretty counterintuitive for those used to working with macroscopic fibre composites. For example, glass fibre fill adds more strength than CF fibre fill (CF fibre fill adds more stiffness). Because it's not so much about the strength of the fibres themselves, but rather how well the polymer matrix grips the fibres.
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Yeah it's weird stuff. I've done a of normal fiber reinforced composites, and to me the filaments just feel like completely normal filaments with the same kind of different tradeoffs you get switching between plastic types, such as more yield strength, lower toughness, less surface detail rather than a whole new material like the macroscopic type.
I didn't know that about glass vs carbon. At the moment, I'm printing for business reasons so I'm sticking to things where I have a reasonable expectation of being
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I've done my first test of buying a whole pallet of filament straight from a Chinese manufacturer. It's a risk - it could be all junk - but if it's usable, the price advantage is insane. Like $3/kg for PETG at the factory gate (like $5/kg after sea freight and our 24% VAT). Versus local stores which sell for like $30/kg.
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I've done my first test of buying a whole pallet of filament straight from a Chinese manufacturer.
I'm curious what the shipping is like. I've looked at Alibaba and Aliexpress for buying certain items, and over a certain size, the shipping is quite punishing. For something like a side channel blower (i.e. palette sized, 15-20kg or so), the prices are a lot better in China, but the shipping eats up the difference, to the point where local vendors are competitive price wise but with faster shipping and better
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CF-ABS is NOT like fiberglass at all. The CF is chopped into fine bits.
A part made with fiberglass which was somehow made with a resin that was as heat affected as ABS would have the exact same problem as the part that failed. The problem isn't the nature of the CF, the problem is that it can't do its job if the plastic melts.
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The situation was worse than I thought. According to the AAIB report [service.gov.uk], they tested the material and found the glass transition temperature to be about 53C, so the jackass printed it in PLA.
Re: 3D printing wasn't the problem (Score:2)
I wonder if it was supposed to be used in lost PLA casting and then wasn't, or if they were just very very stupid
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I'm thinking very very stupid. No sprues for casting.
Who's Stupid? (Score:2)
So the nanometer lathing of tungsten steel is no longer needed. We'll just print it at the milimeter level out of resin!
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As was mentioned earlier, this isn't talking about a turbine blade, it's talking about an air intake. Also, "millimeter level"? This isn't the early 2000s. I usually print with a layer thickness of 100 microns, and the printer's control of the Z axis is well finer than that.
The problem is that they made an insane choice of a material for the intake. It was supposed to be ABS-CF, but instead it was apparently PLA. Corn plastic. The stuff people make Warhammer figures and the like out of.
Better info (Score:2)
According to an AAIB Field Investigation report [service.gov.uk] (pg. 4), two samples from the intake were tested and found to have a glass transition temperature of 54.0C and 52.8C
So some idiot printed them in PLA. PLA is great but is very much NOT temperature resistant. It has been known to sag in a hot car.
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PLA is also not very durable. In hot and humid climate, PLA can decompose in a few months. PLA is, in some sense, a great prototyping material but not suitable for most other tasks.
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I mean, the fact that PLA's chain is vulnerable to scission by water is in a way nice - not just from a compostability perspective, but from a health perspective too. I don't mind sanding PLA, for example, because PLA microplastics aren't going to build up in your body the way that, say, PETG or ABS might. At 60C, PLA microparticles decompose fully in just 10h. It's significantly slower at lower temperatures, but still, they don't persist. Also, a lot of people like that it's made out of corn rather tha
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Also, since it's Poly Lactic Acid, our metabolism is already well equipped to deal with the breakdown product.
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It's great for things that will be indoors at room temperature. I made a snap-on camera mount for my monitor that has held up great. But if it was a dash mount, it would need to be PETG or CF-PA6 to not sag in the summer.
an old problem (Score:2)
People have been making their own substandard parts long before 3D printing. I've seen things made from wood, resin, plaster, and even papier-mâché
Who'd a thunk the plastic would melt?! (Score:1)
Kinda click-bait story summary (Score:1)
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Yeah, if you had injected moulded PLA, it would have been just as terrible
I hate 3D-printed parts (Score:2)
To give more details, I hate it when nowadays you order a part online and you get a 3D-printed piece of shit instead. I've had several bad experiences, one being a wheel for a suitcase, when I put the empty suitcase up, the wheel broke off. Others are 3D-printed plastic to replace a metal bike part; really ?!? Even things like wood knife handle replaced by 3D-printed garbage !
The very s