Large gears on a bridge in Geneva, Switzerland

Gear Up: A 15-Minute Intro On Involute Gears

If you’re into CNC machining, mechanical tinkering, or just love a good engineering rabbit hole, you’re in for a treat. Substack’s [lcamtuf] has written a quick yet insightful 15-minute introduction to involute gears that’s as informative as it is accessible. You can find the full article here. Compared to Hackaday’s more in-depth exploration in their Mechanisms series over the years, this piece is a beginner-friendly gateway into the fascinating world of gear design.

Involute gears aren’t just pretty spirals. Their unique geometry minimizes friction and vibration, keeps rotational speeds steady, and ensures smooth torque transfer—no snags, no skips. As [lcamtuf] points out, the secret sauce lies in their design, which can’t be eyeballed. By simulating the meshing process between a gear and a rack (think infinite gear), you can create the smooth, rolling movement we take for granted in everything from cars to coffee grinders.

From pressure angles to undercutting woes, [lcamtuf] explores why small design tweaks matter. The pièce de résistance? Profile-shifted gears—a genius hack for stronger teeth in low-tooth-count designs.

Whether you’re into the theory behind gear ratios, or in need of a nifty tool to cut them at home, Hackaday has got you covered. Inspired? Read the full article by [lcamtuf] here.

Custom Mouse Rocks Neat Thumbstick Design

A mouse is just two buttons, and a two-dimensional motion tracking system, right? Oh, and a scroll wheel. And a third button. And…now you’re realizing that mice can be pretty complicated. [DIY Yarik] proves that in spades with his impressive—and complex—mouse build. The only thing is, you might argue it isn’t really a mouse.

The inspiration for the mouse was simple. [Yarik] wanted something that was comfortable to use. He also wanted a mouse that wouldn’t break so often—apparently, he’s had a lot of reliability issues with mice in recent years. Thus, he went with a custom 3D-printed design with a wrist rest at the base. This allows his hand to naturally rest in a position where he can access multiple buttons and a central thumbstick for pointing. In fact, there’s a secondary scroll control and a rotary dial as well. It’s a pretty juicy control surface.

The use of a thumbstick is controversial—some might exclaim “this is not a mouse!” To them, I say, “Fine, call it a pointing device.” It’s still cool, and it look like a comfortable way to interface with a computer.

We’ve seen some other neat custom mice over the years, too, like this hilarious force-feedback mouse. Video after the break. Continue reading “Custom Mouse Rocks Neat Thumbstick Design”

FREE-WILi Turns DC32 Badge Into Hardware Dev Tool

With few exceptions, electronic event badges are often all but forgotten as soon as the attendee gets back home. They’re a fun novelty for the two or three days they’re expected to be worn, but after that, they end up getting tossed in a drawer (or worse.) As you might imagine, this can be a somewhat depressing thought thought for the folks who design and build these badges.

But thanks to a new firmware released by the FREE-WILi project, at least one badge is going to get a shot at having a second life. When loaded onto the RP2350-powered DEF CON 32 badge, the device is turned into a handy hardware hacking multi-tool. By navigating through a graphical interface, users will be able to control the badge’s GPIO pins, communicate over I2C, receive and transmit via infrared, and more. We’re particularly interested in the project’s claims that the combination of their firmware and the DC32 badge create an ideal platform for testing and debugging Simple Add-Ons (SAOs).

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USB-C For Hackers: Reusing Cables

Your project needs a cable, and since USB-C cables are omnipresent now, it’s only natural to want to reuse them for your evil schemes. Ever seen USB 3.0 cables used for PCIe link carrying duty? It’s because USB 3.0 cables are built to a reasonably high standard, both sockets and cables are easy to find, and they’re cheap. Well, USB-C cables beat USB 3.0 cables by all possible metrics.

Let’s go through USB-C cable reuse in great detail, and see just what exactly you get when you buy either a gas station C-C USB 2.0 cable, or, the fanciest all-features-supported 240 W Thunderbolt cable that money can buy. Looking for a cable to cut, or something to pass a seriously high-speed link? You’re reading the right article.

The Omnipresent Cables

USB-A to USB-C cables are the least interesting. They’re equivalent to a microUSB to USB-A cable, except there’s a resistor on the USB-C plug, connected from VBUS to one of the CC pins. That’s it. The cable contains four conductors, there’s really not much new. Save these cables for all the devices still built without the 5.1 kΩ resistors.

Now, a USB-C to USB-C cable – let’s say, 60 W max, the default USB-C cable capability. If your cable says anything less than 60 W, say, “2 A” or “15 W”, that’s a lie – it can handle 60 W no problem, all USB-C to C cables can do 60 W. This cable is also cool – for one, it has five conductors; GND, VBUS, D+, D-, and CC. Two of them (GND and VBUS) are guaranteed to be thick enough to carry 3 A without much voltage drop if any, too!

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There’s Now A Wiki For Hacking Redbox Machines

With the rapidly evolving situation surrounding the Redbox vending machines still out in the wild, it’s about time somebody put together a Wiki to keep it all straight.

The unredbox wiki has information on the various different hardware revisions that Redbox put out into the wild, from the regular outdoor machines to the weird indoor blue variant. The site also has breakdowns on individual components. For example, it covers the computers inside the machines, built by Dell, Lenovo, and Premio, and bits and pieces like the DVD carousel and the modems used inside.

Basically, if you’re working with these machines and you don’t have a manual, this resource could help you out.  As could the neat video below that shows the internals of a Redbox machine during the reloading process.

Whatever you do, though, don’t steal the kiosks. There’s folks handling that already, you’re not allowed to just walk up and haul them away. Check out our earlier coverage of people that are still out there renting from these machines, too.

Continue reading “There’s Now A Wiki For Hacking Redbox Machines”

Rendering of a JetZero blended wing body aircraft with US Air Force markings. (Credit: US Air Force)

Blended Wing Body Passenger Airplanes And The End Of Winged Tubes

The SR-71 with its blended wing body design. (Photo by Tech. Sgt. Michael Haggerty, US Air Force, 1988)
The SR-71 with its blended wing body design. (Photo by Tech. Sgt. Michael Haggerty, US Air Force, 1988)

Ask someone to picture an airplane and they’re likely to think of what is essentially a tube with wings and a stabilizing tail tacked onto one end of said tube. Yet it is also no secret that the lift produced by such a tube is rather poor, even if they’re straightforward for loading cargo (static and self-loading) into them and for deciding where to put in windows. Over the decades a number of alternative airplane designs have been developed, with some of them also ending up being produced. Here most people are probably quite familiar with the US Air Force’s B-2 Spirit bomber and its characteristic flying wing design, while blended wing body (BWB) maintains a somewhat distinctive fuselage, as with for example the B-1 Lancer.

Outside of military airplanes BWBs are a pretty rare sight. Within the world of passenger airplanes the tube-with-wings pattern that the first ever passenger airplanes adopted has persisted with the newest designs, making it often tricky to distinguish one airplane from another. This could soon change, however, with a strong interest within the industry for passenger-oriented BWBs. The reason for this are the significant boosts in efficiency, quieter performance and more internal (useful) volume, which makes airline operators very happy, but which may also benefit passengers.

With that said, how close are we truly to the first BWB passenger airplane delivery to an airline?

Continue reading “Blended Wing Body Passenger Airplanes And The End Of Winged Tubes”

Measuring The Mighty Roar Of SpaceX’s Starship Rocket

SpaceX’s Starship is the most powerful launch system ever built, dwarfing even the mighty Saturn V both in terms of mass and total thrust. The scale of the vehicle is such that concerns have been raised about the impact each launch of the megarocket may have on the local environment. Which is why a team from Brigham Young University measured the sound produced during Starship’s fifth test flight and compared it to other launch vehicles.

Published in JASA Express Letters, the paper explains the team’s methodology for measuring the sound of a Starship launch at distances ranging from 10 to 35 kilometers (6 to 22 miles). Interestingly, measurements were also made of the Super Heavy booster as it returned to the launch pad and was ultimately caught — which included several sonic booms as well as the sound of the engines during the landing maneuver.

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