Dramatically Increasing Usable Closet Space

September 13, 2026 by No comments

As any science YouTuber or first-year physics student is quick to point out, the universe is mostly empty space. Not just space itself, but the amount of “empty” space between nuclei and their electrons is also huge. Getting rid of this empty space results in all kinds of interesting phenomena like degenerate matter and black holes. But the concept can be extrapolated into our daily lives as well; many things are so filled with air that we can get a lot more usable storage space by compressing them down a little bit. [Super Valid Designs] took this concept to a coat closet, building one that can hold an impressive number of coats.

He started by looking at an existing closet, which could hold around 21 coats but only if someone used two hands to cram the coats into the space. After a trip to a store which sells rugs, he saw a much better design that lets all the rugs pivot like the pages on a book, and took this idea to his closet using a similar mechanism designed for storing large blueprints instead of rugs. The closet he built around this mechanism has two hinged doors which allow a person easy access to the coats, and when opened the blueprint hangers pivot out like a book, allowing the coats to not only be easily accessed without disrupting the other coats, but also allow them to be compressed down by the closet door for storage.

For comparison, the original closet could only hold 10 coats when restricted to single-hand operation and 21 when using both. The new closet design is smaller, and can hold 24 coats with a single hand and over 30 when using both, a dramatic improvement of closet efficiency. To top it off, a set of cupboards on top and bottom allow for storing shoes and hats as well, and there’s even a garage for a robotic vacuum cleaner. Surprisingly, we don’t see many closet optimization builds around here. The closest we can come is another traditionally small space, a college dorm.

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Re-creating NASA’s Heat Shield Problem

September 13, 2026 by 5 Comments

After the Orion capsule of the Artemis I lunar mission returned to Earth, it was found that massive chunks of its heatshield had been ripped off, posing a serious risk to any future missions. In a recent video in which [polymatt] takes a break from repairing old laptop shells and the like, he tries to recreate the Orion’s heatshield using a variety of methods and materials.

For this test a number of samples were created, each using the same kind of segmented structure as the larger Orion heatshield. The filler was created from the published materials for the heat shield by NASA, requiring just serious mixing.

The resulting samples were then cured with thermocouples inserted, before they got blasted with the heat from a propane torch, trying to simulate the various re-entry patterns.

Perhaps unsurprisingly, the results matched the findings by NASA for why the Orion’s heat shield had failed, being the build-up of gases due to the sustained pyrolysis processes that eventually fractured the material. Despite some experimental flaws that injected residual heat from the copper structure, this still seems to be a pretty good setup to test ablative heat shields in DIY lab conditions.

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Hackaday Links: September 13, 2026

September 13, 2026 by 4 Comments

We try to steer clear of politics and societal issues here at Hackaday, so a protest is not usually the sort of thing we’d cover. But we figure it’s safe enough to bend the rules a bit when the ones doing the protesting happen to be robots.

About 30 bots gathered — or at least were commanded to gather by the event organizers — in Warsaw to spur discussion about the impact AI and robots will have on the labor market. Beyond getting public and media attention, the demonstration was also designed to raise awareness of what modern humanoid robots can do. While we appreciate the idea of showing robots taking the “jobs” of the protesters, it does seem somewhat ironic that marching around and chanting for hours is exactly the sort of repetitive work that most people would be happy to see taken over by machines.

Although we hope these protests remain peaceful, there’s always a chance things can turn violent when tensions are high. Should things go south, take comfort in the knowledge that a company in Japan has introduced a robot ambulance service. It’s probably more accurate to compare it with roadside assistance, as the goal is to repair the robot on-site. That said, if the fault is more serious, they can bring the damaged bot back to HQ. Of course, the major difference between this program and a traditional ambulance service is that they’ll be able to bring along a spare robot that can take over the patient’s job while repairs are being made. Should anyone start doing that for humans, expect a few more protests.

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Rusting An E-scooter (In A Good Way)

September 13, 2026 by No comments

It is a classic Hackaday situation. You have an Egret GT E-scooter. It has a screen that shows the usual dash stats, but that led to an annoyance. You could accidentally enter firmware update mode and, from there, enter operational mode without the security PIN. [Ben] couldn’t let that stand, so he reverse-engineered the protocol and rewrote the firmware in Rust. As he put it, “… because I have to break… everything I own…” We get it.

The mobile app was useful for some basic info, since sniffing Bluetooth is fairly easy and analyzing mobile code is, more or less, straightforward. Analysis revealed some data that doesn’t show on the display and that several things are sent back to home base tagged with the scooter’s unique ID — another reason to gut the existing firmware.

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A 386 PC For Your RP2350

September 13, 2026 by 12 Comments

We’re at a fortunate moment: microcontrollers available at modest prices are edging into the capability level previously reserved for full-fat systems and can, through emulation, run software beyond classic 8-bit home computers, consoles, or old arcade games. A project we’ve been watching for a while is tiny386, an emulator for ESP32 boards that provides a 386 PC with just enough 486 and 586 instructions enabled to run a modern Linux kernel. Now we’re pleased to note that this platform is making it to the RP2350, with ports for both the FRANK emulation platform and the Waveshare Pi Zero boards. You can now have a 32-bit PC with all the peripherals, including VGA and DVI/HDMI, for the cost of an inexpensive development board.

Having seen tiny386 run on its minimum-spec ESP32 platform, we’ll concede that while it’s usable, it’s not the fastest experience, but the RP2350 port promises better performance. It’s not for a modern full-fat Linux distro, but should work well for running older operating systems such as DOS, or Windows 3.1 and 95, or even a lean Linux setup. This has fascinating potential: while these systems are old, they still have an enormous software library. The idea of useful general-purpose computing, 1990s style, in the palm of the hand, is interesting.

If you’re curious, you can find tiny386 here and the FRANK boards here. Maybe they’re a better route to ’90s fun and games than a 386 laptop.

Analyzing The FScale Instruction In Intel’s 8087 FPU

September 13, 2026 by 4 Comments

During his continuing analysis of the architecture and microcode of Intel’s highly influential 8087 floating point unit (FPU) co-processor, [Ken Shirriff] has now arrived at the point where he can put together how the 8087’s microcode implements various x87 instructions. One of these, the FSCALE instruction turned out to be far more complicated than assumed, with one might assume to be a straightforward powers-of-two scaling turning out to entail over 140 micro-instructions and three levels of sub-routine calls just to handle all cases.

The annotated die shot in the heading image shows the functional blocks that are used by this one x87 instruction, to give some kind of idea of what amount of hardware even ‘just’ scaling a floating point number involves.

Much like with the x86’s CISC-style ISA, these 8087 instructions break down into individual steps that involve everything from loading values into registers, performing operations, checking for and handling error conditions as well as stack management. As can be seen in [Ken]’s breakdown of the FSCALE implementation in the 8087 it’s all very logical, taking a high-level instruction and doing all that’s needed for a robust implementation, without bothering the developer with the details.

Of note is that the 8087’s implementations led to the IEEE 754 floating point standard, providing what definitely at the time was one of the most mathematically accurate FPUs that somehow still was financially responsible enough to make it into a relatively affordable PC.

An angular, 3D-printed base holds two icosahedra with numerals on their faces. Each icosahedron has a zig-zagging path running through it, showing red gears inside.

Keeping Time On Tumbling Icosahedra

September 13, 2026 by 8 Comments

Clocks are almost the ideal devices to inspire creativity in hackers — they have a simple, well-defined task, but there’s an almost unlimited number of ways to carry it out. [ekaggrat singh kalsi]’s OVODYO is a particularly intriguing approach, tumbling a pair of icosahedral counters to display the current time.

Each 3D-printed icosahedron has numerals sunk through each of its twelve sides, and is raised above the base of the clock on a brass support shaft. An inner drive shaft runs through the center of the support shaft and drives a set of beveled gears. These spin the outer shells around two axes, periodically cycling through all twelve faces. The pattern in which an icosahedron rotates means that only set of numerals appears upright at a time, making it easier to distinguish the time.

A split path around the icosahedra both lets them rotate around the support shaft and shows off the internal gearing. On the control side, an ATmega8 drives a pair of stepper motors with drv8833 motor drivers, using a hall effect sensor to detect each indicator’s position. Since the minutes dial only gives the time in five-minute intervals, it also drives an LED strip to indicate the exact minute.

[ekaggrat] has a long history of creative clock designs, from this dynamic chain-link sculpture to a hair-tie clock or a mechanical seven-segment display.

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