Mysterious Files PH

Sunday, August 2, 2026

Turning Fruits Into Ethylene and Ethane Refrigerant

August 02, 2026 0

One of the best parts about DIY chemistry and physics projects is that you get to decide how early in the supply chain you want to begin, such as with [Hyperspace Pirate]’s adventures in ethanol production from sugar fermentation. Although you can certainly just buy packs of sugar and yeast from the store and pretend that this will be helpful once the world embraces its Mad Max era, you may as well start with the stuff that actually grows on trees, like fruit.

While you could use the ethanol produced this way as ethanol fuel in combustion engines and the like, you can also turn the ethanol into ethylene and ethane. That way you can fill up your refrigerator, freezer, and air conditioner to keep your perishable foods and yourself fresh as the outside world descends into highly questionable fashion choices.

Even outside such a scenario it makes sense to generate your own ethane and ethylene, due to how much these refrigerants cost. Once you have the ethanol, some aluminium oxide catalyst at 350°C is enough to produce ethylene and water. Producing ethane is admittedly a bit more involved, requiring acetobacter bacteria to produce acetic acid, along with baking soda, a platinum anode and a few more odds and ends.

Producing butene and even longer chains from ethylene is also possible as a next step, but this gets even hairier than producing ethane from ethanol, so we’re likely to see this in a future update after all the low-hanging fruit has been harvested.


Saturday, August 1, 2026

Bike Trainers as Video Game Controllers

August 01, 2026 0
Bike Trainers as Video Game Controllers

While we’ve largely settled on analog sticks and digital buttons for controlling video games, there’s all sorts of projects to create truly esoteric controllers that allow playing games in unique ways. This one from [sukolupo] lets you use data from standard bike trainers to get your virtual character moving.

Called Deck de France, it maps the data coming from one of the supported bike trainers to a virtual controller which can then be “plugged in” to a gaming console of choice, in this case a Steam Deck mounted to the trainer’s handlebars. Although a bike trainer doesn’t have the same number of inputs as a modern gaming controller, it does have enough to play games like Rocket League. As you might expect, it’s also perfect for biking titles such as the Tour de France series.

As far as unique controllers for video games go, this one is surely up in the rankings with a real trombone or a controller purpose-built for riding virtual horses. It’s also a great way for those who are getting a bit bored of riding their trainers to breathe some new life into their exercise routine. We’ve also seen some open-source alternatives for modern bike trainer software as well, which is another great way to get excited about exercise equipment too.


Stewart Platform Walker Gains Feeling In Legs From Resistors

August 01, 2026 0

Stewy is a very interesting robot, with some slightly odd kinematics. Its head is a Stewart platform, which is a common-enough 6-DOF actuated plate normally used with a fixed base. By connecting legs to the same servos running the Stewart platform, [JD] turned it into an adorable hexapod walker. The walker had a problem, though: it can’t feel its feet, and [JD] thinks that would make it much more mobile on uneven surfaces. So he got some resistors to turn the cheap servos in its legs into force-sensing actuators.

Well, almost. He’s not actually putting strain gauges or anything like that into the legs; he’s just measuring the voltage drop across a resistor in series with the servos. Since the motors draw more current the more torque they’re putting out, he has a very quick and easy way to sense the current and thus the torque using good old Ohm’s law and an analog input on the microcontroller driving the robot. It’s a simple hack, but the data he’s getting is surprisingly good for how much work it is to add to a robot, as you can see in the video — at least once he slowed down the servos a touch.

Perhaps this isn’t a ground-breaking innovation, but [JD] does a very good idea explaining it. Of course if you want to use resistors to sense force directly, force-sensitive resistors are a thing that we’ve seen in everything from Twister-mat MIDI controllers to self-leveling 3D printers.


Open Source Stream Deck Targets Flexibility

August 01, 2026 0
Open Source Stream Deck Targets Flexibility

Stream decks are very useful when you’re live on camera and you need to hit some complicated macro at a glance. However, there is sometimes a perception that commercial options are a touch expensive for what they are, an attitude which has spawned many DIY builds. [Fady Faheem] has developed just such a device of his own.

Named Stream32, the build is intended to be simple to understand and adapt to one’s own individual workflow. Putting one together is as easy as buying a display, hooking it up to an ESP32, flashing the firmware, and then adding pages of shortcuts as desired. [Fady] has designed the firmware to be flexible with regards to screen choice — currently, it can be set up for a 4″ Waveshare LCD or a nice roomy 10.1″ display from Elecrow. Since it’s open source, adapting to a wider range of displays is a potential exercise for the builder.

The great thing about custom stream decks is you have all the freedom in the world to customize them to your own specific setup. Play with the code, the functionality, the visual layout—all to suit your own needs. If you’re working on your own custom hardware, be sure to tell us on the tipsline.


Browser-based 3D Editor Covers The Basics While Staying Local

August 01, 2026 0
Browser-based 3D Editor Covers The Basics While Staying Local

Got an idea and want to make a simple 3D model, but don’t want to install a full-fledged CAD modeling suite and queue up a few hours of tutorial videos? Check out SketchForge, a 3D modeling program that runs locally in one’s browser without any need for an account, or external services.

SketchForge takes a more WYSIWYG approach to 3D modeling by making it easy to put an object together with primitive shapes, and making it extra easy to specify dimensions and align parts with one another. There’s also a sketch feature that makes it easier to create more complex shapes by making a 2D drawing, then extruding or revolving it into a solid. We like that it has STEP format export as an option, making it easy to import your creation into another CAD program of your choice later. Most 3D printer slicers natively support the STEP format nowadays, too.

It’s a bit reminiscent of Tinkercad in concept, but entirely local. It’s still new, but there’s a demo online that gives a good idea of its capabilities if you’d like to give it a spin.

We’re reminded of CaDoodle, another project that takes the “Tinkercad, but local” approach but as a standalone executable, instead of browser-based.


Friday, July 31, 2026

Tiny Desktop Robot Has Radar

July 31, 2026 0

One thing our futuristic world is largely lacking in is droids and robot companions and the like. [solitary dev] is helping to rectify that problem by building a little robot called TongDou.

As [solitary dev] tells it, TongDou is a “tiny open-source desktop gremlin.” An ESP32-S3 serves as TongDou’s brain, buried inside a tasteful brass tube chassis. An OLED display is TongDou’s face, and he uses a pair of wheels driven by gearmotors for locomotion. A speaker plays back pre-recorded voice lines, while a 24GHz radar and an IMU enables TongDou to keep track of the space it’s moving through. They are publishing the design files on Github so other makers can build their own if so desired.

[solitary dev] hopes to develop TongDou into something to make a “workspace feel less dead.” It’s not dissimilar from the way studios used to use robots to liven up otherwise hackneyed movies and TV shows, and we could absolutely use some of that whimsy in the real world. We’ve featured other fun desktop companions before, too. Video after the break.


Hackaday Podcast Episode 380: 3D Printing the Rainbow, IR and IP Camera Hacks, and Americium 241 on the Loose

July 31, 2026 0
Hackaday Podcast Episode 380: 3D Printing the Rainbow, IR and IP Camera Hacks, and Americium 241 on the Loose

Elliot Williams and Al Williams got together to compare notes on the most interesting posts this week on the site. As usual, there are just too many choices, so you’ll have to settle for just the few that can fit in a podcast. The guys were excited about 3D printing — both FDM and SLA — as well as a few camera projects. Ever wanted your own starship? They do, too, and you’ll hear about it along with portable radar and more.

Want to make flexible PCBs? Fill up a carbon dioxide tank? Or play Doom via regular expressions? Tune in, and you’ll find out about those stories and more.

Follow along with the links, and as always, tell us what you think about this episode in the comments! Better still, drop us a note in the mailbag, and you might hear your question on a future episode. You can record audio or send us a message, and one of the hosts will read it on your behalf.

Direct download in IR color-corrected DRM-free MP3.

Episode 380 Show Notes:

News:

Mailbag:

  • [Marcel] wants more info about the next Hackaday Europe, and delivers a great excuse for not making it this year.
  • A note about IRCs and QSL managers from [Reese Johnson].
  • QSL Bureau
    • Drop your comments and questions in audio or text format to mailbag@hackaday.com, and you might hear it on a future podcast!

Interesting Hacks of the Week:

Quick Hacks:

Can’t-Miss Articles: