In today’s episode of “AI Is Why We Can’t Have Nice Things,” we feature the Hertz Corporation and its new AI-powered rental car damage scanners. Gone are the days when an overworked human in a snappy windbreaker would give your rental return a once-over with the old Mark Ones to make sure you hadn’t messed the car up too badly. Instead, Hertz is fielding up to 100 of these “MRI scanners for cars.” The “damage discovery tool” uses cameras to capture images of the car and compares them to a model that’s apparently been trained on nothing but showroom cars. Redditors who’ve had the displeasure of being subjected to this thing report being charged egregiously high damage fees for non-existent damage. To add insult to injury, if renters want to appeal those charges, they have to argue with a chatbot first, one that offers no path to speaking with a human. While this is likely to be quite a tidy profit center for Hertz, their customers still have a vote here, and backlash will likely lead the company to adjust the model to be a bit more lenient, if not outright scrapping the system.
Wave Drive Made With 3D Printed Parts
You can get just about any gear reduction you want using conventional gears. But when you need to get a certain reduction in a very small space with minimal to no backlash, you might find a wave drive very useful. [Mishin Machine] shows us how to build one with (mostly) 3D printed components.
The video does a great job of explaining the basics of the design. Right off the bat, we’ll say this one isn’t fully printed—it relies on off-the-shelf steel ball bearings. It’s easy to understand why. When you need strong, smooth-rolling parts, it’s hard to print competitive spheres in plastic at home. Plastic BBs will work too, though, as will various off-the-shelf cylindrical rollers. The rest is mostly 3D printed, so with the right design, you can whip up a wave drive to suit whatever packaging requirements you might have.
Combined with a stepper motor and the right off-the-shelf parts, you can build a high-reduction gearbox that can withstand high torque and should have reasonable longevity despite being assembled with many printed components.
We’ve seen other interesting gear reductions before, too.
Which Browser Should I Use In 2025?
Over the history of the Web, we have seen several major shifts in browsing software. If you’re old enough to have used NCSA Mosaic or any of the other early browsers, you probably welcomed the arrival of Netscape Navigator, and rued its decline in the face of Internet Explorer. As Mozilla and then Firefox rose from Netscape’s corpse the domination by Microsoft seemed inevitable, but then along came Safari and then Chrome.
For a glorious while there was genuine competition between browser heavyweights, but over the last decade we’ve arrived at a point where Chrome and its associated Google domination is the only game in town. Other players are small, and the people behind Firefox seem hell-bent on fleeing to the Dark Side, so where should we turn? Is there a privacy-centric open source browser that follows web standards and doesn’t come with any unfortunate baggage in the room? It’s time to find out. Continue reading “Which Browser Should I Use In 2025?”
Ball Nut Modification Charts A Middle Course Between Building And Buying
A lot of the projects we feature here on Hackaday engender the classic “build versus buy” argument. We’ve always been puzzled by that; if anyone can appreciate the sheer joy of making something rather than buying it, it should be our readers. But there’s something to be said for buying the stuff you can buy and concentrating your effort on the bespoke aspects of the project. It’s perhaps not as exciting, but needs must, oftentimes.
Let’s not forget there’s a third way though, which [Andy] explores with this ball nut modification project. Keen-eyed readers will recall [Andy]’s recent scratch-built ball screw build, in service of some top-secret, hush-hush project related to world domination and total subjugation of humanity. His homebrew efforts in this regard were a great lesson in how to machine a complex mechanism to work in a constrained space. Still, it left folks wondering why he’d go to all the trouble when he could have just trimmed an off-the-shelf part down to size. So, he decided to give that a try.
Continue reading “Ball Nut Modification Charts A Middle Course Between Building And Buying”
FreeBSD At 30: The History And Future Of The Most Popular BSD-Based OS
Probably not too many people around the world celebrated November 1st, 2023, but on this momentous date FreeBSD celebrated its 30th birthday. As the first original fork of the first complete and open source Unix operating system (386BSD) it continues the legacy that the Berkeley Software Distribution (BSD) began in 1978 until its final release in 1995. The related NetBSD project saw its beginnings somewhat later after this as well, also forking from 386BSD. NetBSD saw its first release a few months before FreeBSD’s initial release, but has always followed a different path towards maximum portability unlike the more generic nature of FreeBSD which – per the FAQ – seeks to specialize on a limited number of platforms, while providing the widest range of features on these platforms.
This means that FreeBSD is equally suitable for servers and workstations as for desktops and embedded applications, but each platform gets its own support tier level, with the upcoming version 15.x release only providing first tier support for x86_64 and AArch64 (ARMv8). That said, if you happen to be a billion-dollar company like Sony, you are more than welcome to provide your own FreeBSD support. Sony’s Playstation 3, Playstation 4 and Playstation 5 game consoles namely all run FreeBSD, along with a range of popular networking and NAS platforms from other big names. Clearly, it’s hard to argue with FreeBSD’s popularity.
Despite this, you rarely hear people mention that they are running FreeBSD, unlike Linux, so one might wonder whether there is anything keeping FreeBSD from stretching its digital legs on people’s daily driver desktop systems?
Continue reading “FreeBSD At 30: The History And Future Of The Most Popular BSD-Based OS”
Gears Are Old And Busted, Capstans Are Cool
Zero backlash, high “gear” reduction, high torque transparency, silent operation, and low cost. What is this miracle speed reduction technology, you ask? Well, it’s shoelaces and a bunch of 3D printed plastic, at least in [Aaed Musa]’s latest installment in his series on developing his own robot dog.
OK, the shoelaces were only used in the first proof of concept. [Aaed] shortly upgrades to steel cable, and finds out that steel fatigues and snaps after a few hours. He settles on Dyneema DM-20, a flexible yet non-stretching synthetic rope.
Before it’s all over, he got a five-bar linkage plotting with a pencil on the table and a quadriped leg jumping up and down on the table — to failure. All in all, it points to a great future, and we can’t wait to see the dog-bot that’s going to come out of this.
There’s nothing secret about using capstan drives, but we often wonder why we don’t see cable-powered robotics used more in the hacker world. [Aaed] makes the case that it pairs better with 3D printing than gears, where the surface irregularities really bind. If you want to get a jumpstart, the test fixture that he’s using is available on GitHub.
Continue reading “Gears Are Old And Busted, Capstans Are Cool”
Mostly Printed CNC Gets A Few Upgrades
The Mostly Printed CNC is famous for two things. First, being made mostly from 3D printed parts and commonly available steel tubing. Second, because of the materials used, its rigidity isn’t fantastic. But any CNC router is better than no CNC router, and [Alan Reiner]’s “Mostly Mostly Printed CNC” upgrades the base MPCNC into a much more capable unit.
MPCNC purists may want to look away, as the video below shows [Alan] committing the heresy of adding linear rails to his machine. The rails were sourced from VEVOR and at less than $100 for 10 meters, it must have been hard to resist. The rigidity wasn’t amazing — witness the horrific chatter at around the 5:15 mark — but [Alan] sorted that out with some aluminum extrusion and printed adapters.
Those upgrades alone were enough to let [Alan] dive into some aluminum cutting, but he also wanted to address another gripe with his base build: the Z-axis backlash. The fix there was to add another lead screw nut on an adjustable carrier. By tweaking the relative angles of the two opposed nuts, almost all of the backlash was taken up. [Alan] also replaced the motor coupling on the Z axis with a Lovejoy-style coupler, to remove as much axial compliance as possible.
Along with the motion control mods, [Alan] improved work holding and added an enclosure to tame the chip beast, along with some upgrades to the control electronics. The results are pretty good and appear well worth the modest added expense. Maybe a wireless controller can be next on the upgrade list?