9 ms·
> The machine also automatically outputs a report that details any deviations during printing, removing the need for postfabrication qualification. Anyone who'
by Etheryte 2y ago
> The machine also automatically outputs a report that details any deviations during printing, removing the need for postfabrication qualification.
Anyone who's previously worked with 3D printing knows that this simply does not pass any kind of a sniff test. Both preventing and detecting internal defects is one of the, if not the hardest problem in 3D printing. There are many large companies trying to find ways to reliably solve just this problem alone. Saying that this method doesn't require any checks after production is simply false.
- guax 2y agoTitan submersible sound detection system vibes.
- nathan_compton 2y agoExactly what I thought.
- cjbgkagh 2y agoI'm not sure how many people know about their 'sound detection system'. Carbon fiber is a fickle beast and is prone to such failures so that alone worried me, but it was incredible for me to learn that they expected some sort of early warning from cracking.
- ladams 2y agoDo you have a link? Google just gives results about the US Navy detection of the implosion…
- azornathogron 2y agohttps://www.businessinsider.com/oceangate-2020-boasted-incredible-accuracy-detecting-titanic-sub-hull-flaws-2023-7 https://www.businessinsider.com/oceangate-2020-boasted-incre...
- lucianbr 2y agohttps://www.youtube.com/watch?v=6LcGrLnzYuU https://www.youtube.com/watch?v=6LcGrLnzYuU As I remember he talks about the sound detection thing.
- NortySpock 2y agohttps://www.wired.com/story/titan-submersible-disaster-inside-story-oceangate-files/ https://www.wired.com/story/titan-submersible-disaster-insid... Recent one-year-lookback story by Wired.
- raverbashing 2y agoWell there were probably some early warning signs The problem is that warning sign comes at around 10ms or less before the actual disaster
- rvnx 2y agoIf it would be a Tesla, just enough time for the auto-pilot to disengage and claim it was the fault of the user.
- ETH_start 2y agoTesla autopilot is not supposed to be unmonitored, so any accidents under its control are entirely the fault of the driver. If a driver disengaged 0.1s before impact, they were derelict in their driving.
- abduhl 2y agoOSHA has a nice pamphlet regarding hazard identification and hazard controls. The least effective method of protecting workers is to put the risk on the worker to protect themselves. Your view has a similar vibe to "well they weren't wearing their hard hat and so it's their fault," a view that has been rejected across the board for safety in favor of the view that even letting the situation get to that point is a failure. https://www.osha.gov/sites/default/files/Hierarchy_of_Controls_02.01.23_form_508_2.pdf https://www.osha.gov/sites/default/files/Hierarchy_of_Contro...
- ETH_start 2y agoDriver control IS making the driver responsible, by definition. Tesla is legally required to put the driver in control. This is a driver assist program. There is no way such a program, that is subordinate to the driver and depends on the driver being in control, can protect the driver from not doing their part, and driving.
- sjsdaiuasgdia 2y ago
- hliyan 2y agoWhat does "vibes" mean here? Are you saying that this is a comparable level of negligence, or that it simply personally reminds you of the former case, and nothing else? There are better words available than "vibes".
- guax 2y agoI'm not vibing with your distaste for the vibes.
- numbsafari 2y agoIf they’re not doing post fabrication validation, then the passengers are…
- drlemonpepper 2y agowhat's wrong with testing in prod? /s
- numbsafari 2y agoNothing. Always Be Testing. But _only_ testing in prod is bad.
- deleted 2y ago[deleted]
- surfingdino 2y ago... test dummies.
- vasco 2y agoIf any system could measure its own signal to noise accurately, it wouldn't have any noise in the first place.
- sobellian 2y agoThis is a "truthy" statement that sounds right but is, in fact, false. Radio systems have an easily measurable SNR, but the noise cannot be eliminated.
- vasco 2y agoYou can measure is from outside the system itself if you know the original signal. Of course its possible to measure the noise externally if you know what was transmitted.
- sobellian 2y agoAFAIK this is incorrect. There exist modulation schemes where the received signal power is evident. For Wifi the signal is usually > 10-100x the noise floor and it is modulated with phase-shift keying. So there is no technical problem with seeing a noise floor, then receiving a much larger signal with constant envelope and calculating an SNR. ETA: Just to sharpen the point, this is clearest when considering digital noise and error correction. It is easier for error correction codes to indicate a corrupted message than it is to provide the correct message.
- Dylan16807 2y agoThat only works if you have an ultra-high-resolution record of isolated noise. An accurate measurement of signal-to-noise is just some power levels and basic knowledge of the shapes of the signals. It's easy to figure out and doesn't help you read back your data. It helps you configure appropriate transmission settings and doesn't do much else.
- xxs 2y agoYou may go further and say the rocket would be built on a proper rocky foundation.
- surfingdino 2y agoI too am doubtful. The market is littered with failed 3d printed products, all failed because the designers know nothing about real-life product design or because their deigns are too brittle or melt too easily in heat.
- metal_am 2y agoIt might sound a little wild, but a huge amount of research has been put into getting metal AM parts to be “born qualified.” L-PBF is getting to be a fairly mature technology.
- NortySpock 2y agoTo steelman the argument, maybe they meant "the monitoring system is good enough at catching defects that if none are reported, the engine will probably pass an all-up hotfire test of the engine". Of course you could do a water or air-pressure leak test on the plumbing pretty easily, and you would likely do that on the first 30 engines... But if you have confidence in your build process, maybe the juice isn't worth the squeeze on (say) a direct contact ultrasound void check on every square millimeter of the part. It's all about "how expensive is it to run the test" vs "what is the likelihood the test catches an issue" vs "what's the cost of failing while everyone is watching?" Same reason SpaceX went from dry-dress-rehersals to wet-dress-rehearsals to separate-static-fire-before-launch to hold-down-for-three-seconds-before-launch... The hold-down -before-launch is an integration test that covers everything the previous tests do, so eventually you can start removing redundant tests.
- sandworm101 2y ago>> maybe the juice isn't worth the squeeze In rockets/aerospace, where the failure of any one of a thousand different parts means instant disintegration, checks are always worth the squeeze. Everyone talks about building rockets on the cheap and accepting a slightly-higher failure rate, but in reality that doesn't work. Even a tiny increase in component fault rates translates to total mission failure once multiplied across thousands of vital parts. The answer isn't to not check but to find ways to more efficiently and more thoroughly check each part. This is only more true if one considers reusable rockets where components will be expected to participate in multiple launches.
- giantrobot 2y ago> In rockets/aerospace, where the failure of any one of a thousand different parts means instant disintegration To make matters worse the failure modes don't only affect the launch vehicle itself. A failure of a rocket likely means a total loss of the payload. It also runs the risk of damage/loss of the launch pad, support structures, and hapless down range victims. Rockets contain a significant amount of stored chemical energy, enough to get the payload mass into a stable orbit of the Earth. If you release all of that energy at once as an explosion it will cause a significant amount of damage. Rockets aren't something to goof around with and make assumptions about safety.
- la64710 2y agoYes and innovation curve tends to go down in large companies because of barriers which a startup is not bounded by. This is how future big companies are created.
- skybrian 2y agoI’m curious about why that is. Naively, it seems like printing layer by layer would allow for a lot of inspection. Maybe even photograph each layer as you go? And then test and go back to see what kinds of defects were apparent in the photos.
- dotnet00 2y agoIt's just that it's very easy for deviations from what the sensors see to occur. In traditional 3d printing, this can be stuff like a sensor switch wearing out, maybe physically moving slightly, being temperature sensitive, maybe the frame has changed shape slightly due to heat, moving the sensor a little, maybe something in the microcontroller happened to cause a slight delay in reading the sensor, or looseness developing in the motion system, or something being slightly out of alignment, or some component in the extrusion system experiencing momentarily higher friction and so on. The layers are really thin, so manually inspecting them would slow down the printing process drastically. Then, ultimately, what even can you do if there's a defect? The layer has been laid already. If material is missing somewhere, you could have the machine go back and add it, but if there's excess material somewhere, or it's in a form that the machine can't fix, there's not a lot to be done, particularly in applications like rocketry, where your structural strength tolerance are very tight.
- metal_am 2y agoI know for certain that defects in the powder layer can be fixed in binder jet by redoing the recoater. There has been talk in the research world about being able to fix errors in L-PBF but I’m not sure they’ve gone past the research stage. The big point is that you can know a part might be out of whatever your acceptance criteria might be.
- serf 2y ago>It's just that it's very easy for deviations from what the sensors see to occur. right, but this is a problem in any modern precision machining, and it has been (mostly) conquered to a degree that we can produce very precise things in an almost entirely automated fashion. >If material is missing somewhere, you could have the machine go back and add it laser sintering is easier to audit than a normal fdm style print in a lot of ways if you care to take the time to do it. The process can be paused fairly easy with the right machine and right environment, the product can be weighed mid-process, it can have all sorts of vision and laser metrology done to the product midway through production; whatever -- and the mid print failure rate is astronomically lower than extrusion based methods. it doesn't seem that unbelievable to me.
- dim13 2y agoVery Indian approach. Print a report, and call it a day. :D
- LargeTomato 2y agoThey may be skipping small portions of the post-print qual. Or more likely, they're just more confident that the pieces being created are of a certain level of quality. It's a hype-y statement but they're probably trying to highlight that they're doing some sort of software-defined quals.
- digdugdirk 2y agoJust out of curiosity, is your 3D printing experience on the consumer side? Or the professional/commercial side? There are various types of non-destructive testing that could be integrated into a larger scale 3D printer for post-production analysis, and it's a direction I'm surprised there hasn't been more movement in.
- simonebrunozzi 2y agoCheck out Roboze on this. (disclosure: investor). They do a fantastic job with this, and in fact their 3d printing machines are widely used in aerospace and defense.