2026-03-25 13:00:28
If you want to work with robots you can do all sorts of learning with software and simulation, but nothing quite beats getting to grips with real machinery. That was the motivation for [James Gullberg] to build this impressive robot arm.
Featuring six degrees of freedom, the robot arm is mostly constructed of 3D printed components. This let [James] experiment with a wide variety of joint and reducer designs for the sake of learning and investigation. The base of the robot uses a fairly conventional planetary gear drive, while shoulder and elbow joints rely on split-ring planetary gearboxes to allow for high torque density with regards to size. [James] implemented a neat sensing technique here, integrating alternating magnets into the output ring gear which are monitored via a magnetic encoder. The wrist joint switches things up again, running via an inverted belt differential.
Running the show is an STM32 microcontroller, which talks to all the encoders, communicates with a Raspberry Pi over CAN bus, and handles all the necessary PID control loops and step generation for the drive motors. The plan is to run higher-level control on the Raspberry Pi which will run a ROS 2-based software stack. Already, the various joints look smooth and impressive in motion.
If you’re looking to learn about robot arms, you really can’t beat building one. We’ve featured a few projects along these lines before. Most of them aren’t exactly production-line ready, but they will teach you a ton about control, motion planning, and all sorts of associated skills. That experience can be invaluable if you intend to work with robots in industry.
My (mostly) 3D printed Robot Arm
byu/SPACE-DRAGON772 inEngineeringPorn
Thanks to [JohnU] for the tip!
2026-03-25 10:00:15
Although usually nylon (generally PA6) filament is pretty cheap, there are some more exotic variants out there, such as the PA12-based Lyten 3D graphene filament that comes in at a cool $150 for a 1 kg spool. Worse for [Dr. Igor Gaspar] here was that the company doesn’t ship to the EU, and didn’t respond to emails about obtaining a sample for testing. Fortunately he got a spool via a different route, so that he could test whether this is the strongest nylon filament or not.
The full name for this filament is PA1205, though it’s not certain what the ’05’ part stands for. PA12 is a less moisture-sensitive version of PA6, however. Among the manufacturer’s claims are that it’s the strongest nylon filament, as well as very lightweight and heat-resistant. Interestingly the datasheet recommends printing with an 0.6 mm nozzle, which is the only major deviation from typical nylon FDM filaments. Of course, printing with an 0.4 mm nozzle had to be tried.
With a standard PA-CF preset in Bambu Lab’s slicer the printing of test parts worked without issues, which was promising. With load testing the filament made a good showing compared to average PA filaments, though as with most fiber reinforced filaments it’s more brittle than the pure material. Compared to PA-CF this PA1205 was much less brittle than PA-CF, however. Overall it’s not a bad filament, but for the asking price it’s a tough ask.
2026-03-25 07:00:48
Most carpenters and woodworkers find themselves with the problem of disposing of all the sawdust they create when performing their craft. There are lots of creative solutions to this problem, such as adding it compost, using it as groundcover in a garden, adding it as filler in a composting toilet, or pressing it into bricks to burn in a stove. All of these have their uses, but involve either transporting the sawdust somewhere or performing some intermediate step to process it. [Greenhill Forge] wanted to make more direct use of it so he built this stove which can burn the sawdust directly and which provides enough heat for his woodshop.
The design is based on one which is somewhat common in Japan and involves building a vessel with a central tube for airflow, with the sawdust packed around it. The tube is made from a hardware cloth or screen to allow air to reach the sawdust. The fire is lit from the top, closed, and then allowed to burn through the stack. [Greenhill Forge] welded the entire stove from various pieces of sheet metal and bar stock, with a glass plate at the top of the stove to close off the fire and a baffle to control the airflow and rate of burn.
Initially, [Greenhill Forge] thought that the fire would burn from the top down, but this turned out to create a smoldery, messy fire instead of a hot, clean burn. Eventually, though, an ember fell down to the bottom and let the stack burn from the top up, and then it started generating serious heat. He estimates that with around 5 kg of sawdust burning for three hours that it’s about equivalent to a 6 kW stove. While a woodworker might not have enough sawdust to run this stove every day, it could be good to have on hand to use once every few weeks when the sawdust builds up enough. [Greenhill Forge] has been hard at work building unique wood burning stoves lately, like this one we recently featured which generates and then uses charcoal as fuel.
2026-03-25 04:00:36
The US Federal Communications Commission (FCC) is tasked with regulating both wired and wireless communications, which also includes a national security component. This is how previously the FCC tossed networking gear made by Huawei and foreign-manufactured drones onto its Covered List, effectively banning it from sale in the US. Now foreign-made consumer routers have been added to this list, barring explicit conditional approval on said list that would exempt them during a ‘transition phase’.
As per the FCC fact sheet, this follows after determination by an interagency body that such routers “pose unacceptable risks to the national security of the United States [..]”. This document points us to the National Security Determination PDF, which attempts to lay out the reasoning. In it is noted that routers are an integral part of every day life, and compromised routers are a major risk factor, ergo it follows that only US-manufactured routers are to be trusted.
These – so far fictional – US-manufactured consumer routers would have to feature ‘trusted supply chains’, which would seem to imply onshoring a large industrial base, though without specifying how deep this would have to go it’s hard to say what would be involved. The ‘supporting evidence’ section also only talks about firmware-related vulnerabilities, which would imply that US firmware developers do not produce CVEs.
Currently there do not appear to be any specific details on what router manufacturers are supposed to do about this whole issue, though they can continue to sell previously FCC-approved routers in the US.
Although hardware backdoors are definitely a possibility, this requires a fair bit of effort within the supply chain that should generally also fairly easily to detect. Yet after for example Bloomberg claimed in 2018 that Supermicro gear had been infested with hardware backdoors, this started a years-long controversy.
Meanwhile actually verified issues with Supermicro hardware are boringly due to software CVEs. In that particular issue from 2024 two CVEs were discovered involving a lack of validation of a newly uploaded firmware image.
All of which is reminiscent of an early 2024 White House ‘memory safety appeal’ that smelled very strongly of red herring. Although it’s easy to point at compromised hardware with scary backdoors and sneaky software backdoors hidden deep inside firmware of servers and networking devices, the truth of the matter is that sloppy input validation is still by far the #1 cause of fresh CVEs each year, especially if you look at the CVEs that are actually being actively exploited.
As for this de-facto ban on new routers being sold in the US, this will correspondingly not change much here. The best defense against issues with networking equipment is still to practice network hygiene by keeping tabs on what is being sent on the LAN and WAN sides, while a government could e.g. force consumer routers to pass a strict independent hardware and software audit paid for by the manufacturer.
Speaking as someone who used to run DIY routers for the longest time built around FreeSCO and Smoothwall Linux, there’s also always the option of turning any old PC into a router by putting a bunch of NICs and WNICs into it and run SmoothWall, OpenWRT, etc.. A router is after all just a specialized computer, regardless of what the government feels that it identifies as.
2026-03-25 02:30:26
Creating PCBs at home is quite easy these days (vias not withstanding), but even the best DIY methods usually can’t match the resolution offered by commercial PCB production lines. Large traces are easy enough to carve out of copper-backed FR1 or FR4 with even a mill, what if you need something more like 100 µm sized traces with similar clearance? This is what [Giangix] has been experimenting with, using both a fiber laser and chemical etching to see what approach gives the best results.
The thin copper clad boards are put on the 20 Watt fiber laser and held in place with the vacuum table that [Giangix] previously made, using the power of suction to make sure the board doesn’t move. The used laser specifies a minimum line width of 0.01 mm, so that’s clearly fine enough to engrave away the chemical resist layer that is sprayed on top of the copper layer.
After some experimentation, it was found that increasing the trace clearance between the 0.1 mm traces to a hair above 0.1 mm was necessary for the subsequent chemical etching step to work the best, as otherwise some copper was still likely to remain. The chemical etching bath mixture consists of hydrochloric acid and hydrogen peroxide, in a ratio of 2 mL water to 2 mL 30% HCl and 2 drops of 35% H2O2. This is agitated for 90 s to get a pretty good result.
Although the final resistance measurements on the traces is a bit higher than theoretical, comments suggest that maybe some of the copper got removed along with the removal of the resist layer. Perhaps the most interesting question here is whether directly ablating the copper using the fiber laser would give even better results and bypass the etching chemicals.
2026-03-25 01:00:17
Although it may be hard to believe for current generations, there was a time when the Internet and the World Wide Web were not as integrated into society as it is today. The only forms of online ‘social media’ that existed came in the form of IRC, forums, BBSes, newsgroups and kin, while obtaining new software for your PC involved generally making your way over to a physical store to buy a boxed copy, at least officially.
In this era – and those before it – age-verification already existed, with various goods ranging from tobacco and alcohol to naughty adult magazines requiring you to pass some form of age check. Much like how movies also got age-gated, so did video games, with a sales clerk taking a very good look at you before selling you that naughty puzzle game or boxed copy of Quake 3.
Today we’re seeing a big fuss being made about online age-verification, with the claim being that it is ‘for the children’, but as any well-adjusted adult can attest to, this is essentially a big bucket of hogwash.
The concept of restricting certain types of drugs, entertainment, and the operating of automobiles and trucks to specific age groups is a popular one. The general reasoning is that you have to set a limit somewhere because you cannot have toddlers driving lifted 4x4s, smoking a big fat cigar, and chugging down a cold one. As for where set this limit, there is rarely more than scarce evidence for a particular age past childhood being more reasonable than any other, with claims of harm often being dubious at best.
In the case of exposing children to ‘harmful content’, whether in the form of video games or audiovisual entertainment, things get if possible even fuzzier, as proving that such content is indeed harmful is a tough ask. Realistically what we should primarily focus on as responsible adults and parents is the prevention of childhood trauma, as any reasonable person ought to be able to agree that inflicting trauma on a child is a certifiably Bad Thing.
In addition to this, there is also the importance of teaching children why certain types of behavior and excesses are bad, such as why you cannot drink soft drinks exclusively, why you need to eat your vegetables, why torturing small animals to death is absolutely not okay, and that Being Nice to Others is totally something to strive for.
Because children since time immemorial have sought to escape the suffocating hold of age restrictions, this raises the question of whether we can prove that this is in fact traumatic or in any way affects their behavior in a negative manner.
Although in the case of the pre-digital-everything age, sales clerks and adults had a lot more insight into what content you consumed, nobody really believed that with the right contacts you couldn’t get access to all the dirty magazines, violent video games and Parental Guidance (PG) or Adult Only (AO) rated movies.
The reason that I was playing Doom, Doom 2, Duke Nukem 3D and similar titles as a kid in the 1990s wasn’t due to me somehow passing as a certified adult or having an adult purchase it for me in a store, but because a computer-enthusiastic older cousin would copy them zipped up with ARJ across a bunch of floppy disks for me and my younger brother to enjoy. Think warez, but with a personal touch.
This kind of black market culture has always been pretty strong, from 1980s mix tapes and copy parties to buying copied audio CDs off someone at school by the late 90s, whether filled to the brim with explicit lyrics or not. This made ‘age restrictions’ mostly limited by one’s technological means and in how far one’s parents were aware of your illicit activities. Having your own TV and VHS/DVD player or multimedia-capable PC in your bedroom really broadened one’s horizons.
Considering that as a child I was also reading adult literature of the (mostly) non-nekkid variety, including the works of Stephen King and Jan Wolkers, as well as Lord of the Rings, there were many things that I did back then that were age-inappropriate. The main question remains whether any of that harmed or benefited me. This is a highly subjective question to ask, of course, but we do have some science to provide a more objective take on this subject.
Back in the 1990s the idea that violent video games were causing children to become more violent got a lot of traction, mostly due to fighting games and first person shooters like Doom entering the scene. To some people, the premise that playing these games in which you use a variety of weapons and techniques to violently turn pixelated monsters and opponents into pixelated piles of viscera would not have any effect on the developing brain of children and teenagers seemed inconceivable.
The 1993-1994 US Senate hearings on video games came in the wake of the release of controversial games like Night Trap, Mortal Kombat, and by the 1994 hearing, also Doom. Effectively this is where video game ratings became an integral part of this new kind of media, with the Entertainment Software Rating Board (ESRB) being established for the US and Canada.
Yet despite the premise being that exposure to violence and pornography at a young age causes individuals to perform criminal behavior, the crime statistics do not bear this out. In fact, there was a much sharper rise since the 1950s in violent crime across the US, peaking at around 1990, when incidentally lead in the form of tetraethyl lead as a gasoline additive was phased out. This lends credence to the hypothesis that exposure to significant amounts of lead from a young age in one’s environment impaired cognitive development and resulted in said crime wave.
In a 2023 systematic review article by Virginia Lérida-Ayala et al. the causes of behavioral disorders in children and teenagers within the context of internet and video games are considered. Of note is that Internet Gaming Disorder (IGD) is featured in the DSM-5, involving compulsive use of video games to the point that it impairs one’s ability to function.
This negative aspect is of course also contrasted with the positive effects of video games when it comes to things like socializing, cognitive skills and improved self-esteem.
In the review article it is found that playing a very large number of hours of video games per day is correlated strongly with negative effects, yet with the caveat that it’s important not to confuse the order of causality. A strong connection is found between ADHD and escaping into video games, in order to avoid the complexities of emotional and social interactions.
Much like with other types of addictions and substance abuse, they can often act as an escape from reality, in which case the solution does not lie in technological solutions like age restrictions or forcefully limiting the number of hours that a user can play as doing so would merely force the individual to find other forms of escape.
Yet even in these extreme cases of IGD the result is generally not violent or even criminal behavior, but rather a withdrawal from society. This contrasts with the final point being raised, with that of aggression and other forms of dysfunctional behavior, which when left uncontrolled can result in negative feedback from the child or teen’s environment. Yet here too underlying psychological issues such as OCD, depression, social anxiety disorder and so on would seem to be generally present.
In short, it would appear that violent and otherwise age-restricted content do not reprogram a child or teenager’s brain, but it can provide a coping mechanism for those who are dealing with certain mental and psychological issues. Or in other words, when a child or teen is feeling generally happy and content, there should be no negative effects from them indulging in video games and movies, even if they may be deemed to be not quite age-appropriate.
There are many ways in which a child can suffer trauma, but the primary question is whether exposure to age-restricted content can actually induce trauma. This somewhat goes back to the previous section where it’s important to not confuse the order of causality, as after all often trauma can precede problematic behavior rather than be caused by it.
Yet if we look at the list of the types of trauma, it’s not immediately obvious in what way voluntarily opting to listen to explicit lyrics, play violent or erotic video games, would in any way be ‘traumatic’. When contrasted with the list of childhood traumas, such a thing would seem to be rather benign as it’s done out of curiosity tinged with a hint of adventure due to it being ‘for adults’ or at least much older children.
When I look back upon my own experiences playing those violent games – with an occasional stop to pass a stripper in DN3D a few bucks to have them show me some very naughty pixels – it fills me more with a feeling of nostalgia rather than an overwhelming urge to acquire firearms or frequent a strip club.
I will admit that catching that the scene from Child’s Play where Chucky has been thrown into the lit hearth and comes walking out whilst on fire caused child me to fear walking into the dark garage later on. I would fortunately quickly get over that, though I’m still not a fan of snuff-type films like the Saw ones.
Ultimately, when it comes to childhood trauma, this doesn’t appear to be much of a reason to age-restrict certain types of content.
Since the arrival of so-called ‘social media’ the central tenet of never giving out your personal information which was front and center during the 1990s and 2000s got quite literally flipped around. Suddenly we had massive corporations practically begging you to give every last scrap of your personal information, every intimate detail of your daily life and with it every last second of your attention span. They even made an ‘everything device‘ for it in the form of a smartphone that practically ensures that you’ll never be alone with your thoughts again.
The upshot of this reversal is that instead of a mostly comfortable anonymous experience, suddenly every second that you’re awake has been turned into the equivalent of a schoolyard during recess, the watercooler banter at the office and similar social interactions. Along with this comes social anxiety, real-life bullying, and worse, with multiple studies indicating the real harm to children and teenagers in particular, but also to adults.
A recent response to this has been the introduction of social media bans for under-16 year olds, which by itself sounds like a good idea, but this fails to address the many problems that this introduces: from illicit access as demand remains, to the privacy nightmare that ensues as suddenly access to social media requires more stringent identification than accessing a pornographic website.
This raises many questions, such as whether ‘social media’ and the FOMO it introduces is a legitimate addiction, and whether we shouldn’t make being online more anonymous rather than enforce a rather dystopian ‘real name’ policy onto the populace. Contrast this to the old ‘don’t trust strangers’ adage that used to get hammered into the minds of young children, to prevent them from taking up offers from overly friendly people with candy-filled vans.
In how far do children today understand the dangers of the Internet? In a 2019 research article by Jun Zhao et al. a group of UK school children aged 6 – 10 were asked a range of questions in focus groups to see how they see these risks. Now that many children are practically raised by iPads and equivalents, it’s more relevant than ever that the adults in their environment teach them to be safe and to reinforce good online privacy behavior.
The paper was also summarized in an article by Chun Fei Lung, for those whose attention spans are beginning to drift at this point. A major take-away is that children will generally recognize situations that feel ‘scary’ or ‘annoying’, and they agreed that they should ask one of their parents about it before doing anything else.
Perhaps the scariest part is how trusting these children were when it came to platforms they were familiar with. We have seen issues recently pertaining to platforms like Roblox where such trust was exploited by unscrupulous adults, leading to age verification being implemented through the services of Persona. This same identity verification company has also been hired by Discord and has seen its services used in the UK and Australia for their respective online safety legislation.
This then gets us to the crux of modern day online safety, where online anonymity has been replaced with identify verification through private companies. It’s hard to shake the feeling that parental involvement and education campaigns by governments wouldn’t be significantly more effective here. As well as pose a significantly lower risk of having your identity stolen.
Of course, none of this is an easy issue to solve, and there will always be unscrupulous folk around, but treating age verification as some kind of technological silver bullet to a societal issue will always end in tears.
