Typically, if you’re shooting 35 mm film, you’re using it in an old point-and-shoot or maybe a nice SLR. You might even make some sizeable prints if you take a particularly good shot. But you can get altogether weirder with 35 mm if you like, as [Socialmocracy] demonstrates with his “extreme sprocket hole photography” project (via Petapixel).

The concept is simple enough. [Socialmocracy] wanted to expose four entire rolls of 35 mm film all at the same time in one single shot. To be absolutely clear, we’re not talking about exposing a frame on each of four rolls at once. We’re talking about a single exposure covering the entire length of all four films, stacked one on top of the other.

To achieve this, an old-school Cirkut No.6 Outfit camera was pressed into service. It’s a large format camera, originally intended for shooting panoramas. As the camera rotated around under the drive of a clockwork motor, it would spool out more film to capture an image.

[Socialmocracy] outfitted the 100-year-old camera with a custom 3D-printed spool that could handle four rolls of film at once, rather than its usual wide single sheet of large format film. This let the camera shoot its characteristic panoramas, albeit spread out over multiple rolls of film, covering the sprocket holes and all. Hence the name—”extreme sprocket hole photography.”

It’s a neat build, and one that lets [Socialmocracy] use more readily available film to shoot fun panoramas with this old rig. We’ve featured some other great film camera hacks over the years, too, like this self-pack Polaroid-style film. Video after the break.

[Thanks to naMretupmoC for the tip!]

[Chris] had an idea. When playing VR games like BeatSaber, he realized that spectators without headsets weren’t very included in the action. He wanted to create some environmental lighting that would make everyone feel more a part of the action. He’s taken the first steps towards that goal, interfacing SteamVR controllers with addressable LEDs.

Armed with Python, OpenVR, and some help from ChatGPT, [Chris] got to work. He was soon able to create a mapping utility that let him create a virtual representation of where his WLED-controlled LED strips were installed in the real world. Once everything was mapped out, he was able to set things up so that pointing the controller to a given location would light the corresponding LED strips. Wave at the windows, the strips on that wall light up. Wave towards the other wall, the same thing happens.

Right now, the project is just a proof of concept. [Chris] has enabled basic interactivity with the controllers and lights, he just hasn’t fully built it out or gamified it yet. The big question is obvious, though—can you use this setup while actually playing a game?

“I just found the OpenVR function/object that allows it to act as an overlay, meaning it can function while other games are working,” [Chris] told me. “My longer term goals would be trying to interface more with a game directly such as BeatSaber, and the light in the room would correspond with the game environment.”

Nerf blasters typically fire small foam darts or little foam balls. [Michael Pick] wanted to build something altogether more devastating. To that end, he created a rocket launcher with an advanced air burst capability, intended to take out enemies behind cover.

Unlike Nerf’s own rocket launchers, this build doesn’t just launch a bigger foam dart. Instead, it launches an advanced smart projectile that releases lots of smaller foam submunitions at a set distance after firing.

The rocket launcher itself is assembled out of off-the-shelf pipe and 3D printed components.  An Arduino Uno runs the show, hooked up to a Bluetooth module and a laser rangefinder. The rangefinder determines the distance to the target, and the Bluetooth module then communicates this to the rocket projectile itself so it knows when to release its foamy payload after launch. Releasing the submunitions is achieved with a small microservo in the projectile which opens a pair of doors in flight, scattering foam on anyone below. The rockets are actually fired via strong elastic bands, with an electronic servo-controlled firing mechanism.

We’ve featured some great Nerf builds over the years, like this rocket-blasting robot.

LEGO! It’s a fun toy that is popular around the world. What you may not realize is that it’s also made to incredibly high standards. As it turns out, the humble building blocks are good enough to build a interferometer if you’re so inclined to want one. [Kyra Cole] shows us how it’s done.

The build in question is a Michelson interferometer; [Kyra] was inspired to build it based on earlier work by the myphotonics project. She was able to assemble holders for mirrors and a laser, as well as a mount for a beamsplitter, and then put it all together on a LEGO baseboard. While some non-LEGO rubber bands were used in some areas, ultimately, adjustment was performed with LEGO Technic gears.

Not only was the LEGO interferometer able to generate a proper interference pattern, [Kyra] then went one step further. A Raspberry Pi was rigged up with a camera and some code to analyze the interference patterns automatically. [Kyra] notes that using genuine bricks was key to her success. Their high level of dimensional accuracy made it much easier to achieve her end goal. Sloppily-built knock-off bricks may have made the build much more frustrating to complete.

We don’t feature a ton of interferometer hacks around these parts. However, if you’re a big physics head, you might enjoy our 2021 article on the LIGO observatory. If you’re cooking up your own physics experiments at home, don’t hesitate to drop us a line!

Thanks to [Peter Quinn] for the tip!

If you’ve ever seen those cheap LED fiber optic wands at the dollar store, you’ve probably just thought of them as a simple novelty. However, as [Ancient] shows us, you can turn them into a surprisingly nifty little display if you’re so inclined.

The build starts by removing the fiber optic bundle from the wand. One end is left as a round bundle. At the other end, the strands are then fed into plastic frames to separate them out individually. After plenty of tedious sorting, the fibers are glued in place in a larger rectangular 3D-printed frame, which holds the fibers in place over a matrix of LEDs. The individual LEDs of the matrix light individual fibers, which carry the light to the round end of the bundle. The result is a tiny little round display driven by a much larger one at the other end.

[Ancient] had hoped to use the set up for a volumetric display build, but found it too fragile to be fit for purpose. Still, it’s interesting to look at nonetheless, and a good demonstration of how fiber optics work in practice. As this display shows, you can have two glass fibers carrying completely different wavelengths of light right next to each other without issue.

We’ve featured some other great fiber optic hacks over the years, like this guide on making your own fiber couplings. Video after the break.

[Thanks to Zane and Darryl and Ash for the tip! This one was all over the tipsline!]

Fluid simulations are a key tool in fields from aerospace to motorsports and even civil engineering. They can be three-dimensional and complicated and often run on supercomputer clusters bigger than your house. However, you can also do simple two-dimensional fluid simulations on very simple hardware, as [mircemk] demonstrates.

This build is almost like a simple toy that displays particles rolling around and tumbling as you turn it one way or the other. Behind the scenes, an ESP32 is running the show, simulating a group of particles responding to gravity in a fluid-like manner. The microcontroller is  hooked up with an 3-axis gyroscope and accelerometer, which it uses to track motion and influence the motion of the particles in turn. The results of the simple fluid simulation are displayed on a screen made up of a 16 x 16 matrix of WS2812B addressable RGB LEDs, which add enough color to make the build suitably mesmerizing.

There’s something compelling about turning the display and watching the particles tumble and flow, particularly when they’re all set to different colors. [mircemk] also gave the build the ability to operate in several different modes, running “sand,” “liquid” and “gas” simulations and with dynamic coloring to boot.

We’ve seen some great videos from [mircemk] before, too, like this sensitive metal detector rig.

Gonzo journalism has been a hip thing since the 1970s or so, a way of covering a story in a compelling format with more subjectivity and less objectivity. The style has since been applied to all sorts of media, including film—and indeed, the makers of the Gonzo Pi.

The Gonzo Pi is a camera with an open source design, yes, but it’s also a lot more than that. It’s intended to be an entire platform for film-making, all in the one housing. Camera-wise, the design combines a Raspberry Pi with the requisite first-party High Quality Camera, and warps it up in a 3D printed housing. You can build it up with a viewfinder and whatever old-school C-mount or 8 mm film lenses you can lay your hands on.

Beyond that, there’s an editing platform baked in to the device. It’s not unlike the tools in so many social media apps these days. The idea of the Gonzo Pi is that rather than shooting a whole ton of footage and takes and poring over them in great detail later, instead, you run and gun with the device and edit as you go. You can shoot retakes as you need, and even dub in more audio as necessary as you compose your film on the hoof. It’s intended to change the way you make films by virtue of its unique compositional paradigm.

We’ve featured some neat homebrew cameras before, to be sure, but none that quite put the edit suite right in the box.

[Thanks to Moritz for the tip!]

Big-name tube amplifiers often don’t come cheap. Being the preserve of dedicated audiophiles, those delicate hi-fis put their glass components on show to tell you just how pricy they really ought to be. If you just want to dip your toe in the tube world, though, there’s a cheaper and more accessible way to get started. [Jenny List] shows us the way with her neat headphone amp build.

The build starts with an off-the-shelf preamp kit based around two common 6J1 tubes. These Chinese pentode valves come cheap and you can usually get yours hands on this kit for $10 or so. You can use the kit as-is if you just want a pre-amp, but it’s not suitable for headphone use out of the box due to its high-impedance output. That’s where [Jenny] steps in.

You can turn these kits into a pleasing headphone amp with the addition of a few choice components. As per the schematic on Github, a cheap transformer and a handful of passives will get it in the “good enough” range to work. The transformer isn’t perfect, and bass response is a compromise, but it’s a place to start your tinkering journey. Future work from [Jenny] will demonstrate using a MOSFET follower to achieve much the same result.

We’ve seen a great number of headphone amplifiers over the years, including one particularly attractive resin-encased example. Video after the break.

Ever been at a party and landed in a heated argument about exactly where the International Space Station (ISS) is passing over at that very instant? Me neither, but it’s probably happened to someone. Assuming you were in that situation, and lacked access to your smartphone or any other form of internet connected device, you might like the pocket-sized Screen Tracker from [mars91].

The concept is simple. It’s a keychain-sized item that combines an ESP32, a Neopixel LED, and a small LCD screen on a compact PCB with a couple of buttons. It’s programmed to communicate over the ESP32’s WiFi connection to query a small custom website running on AWS. That website processes orbit data for the ISS and the positions of the planets, so they can be displayed on the LCD screen above a map of the Earth. We’re not sure what font it uses, but it looks pretty cool—like something out of a 90s sci-fi movie.

It’s a great little curio, and these sort of projects can have great educational value to boot. Creating something like this will teach you about basic orbits, as well as how to work with screens and APIs and getting embedded devices online. It may sound trivial when you’ve done it before, but you can learn all kinds of skills pursuing builds like these.

Split flap displays! They’re mechanical, clickety-clackity, and largely commercially irrelevant in our screen-obsessed age. That doesn’t mean you can’t have a ball making one of your own, though! [Morgan Manly] did just that, with tidy results.

An ESP32 C3 SuperMini serves as the boss of the operation, running the whole display. The display is designed to be modular, so you can daisy chain multiple characters together to spell longer words. Each module has 37 characters, so it can display the alphabet, numerals 0 to 9, and a blank. Each module contains a 28BYJ-48 stepper motor for controlling the flaps, and a ULN2003 driver board to run it and a PCF8575 IO expander to handle communciation. An A3144 hall effect sensor is also used for positional feedback to ensure the display always shows the right character. The flap mechanism itself is relatively straightforward—a drum with all 37 flaps is until the correct character is reached, with the blank flaps hosting a magnet to trigger the aforementioned hall effect sensor. The flaps themselves are 3D-printed, with filament changes used to color the characters against the background.

If you’ve ever dreamed of building a flap-display clock or ticker, you needn’t dream of finding the perfect vintage example. You can just build your own! The added bonus is that you can make it as big or as small as you like. We’ve seen some interesting variations on the split flap concept recently, too. If you’re cooking up your own kooky electromechanical displays, don’t hesitate to let us know!

LoRa gear can be great for doing radio communications in a light-weight and low-power way. However, it can also work over great distances if you have the right hardware—and the right antennas in particular. [taste_the_code] has been experimenting in this regard, and whipped up a simple yagi antenna that can work at distances of up to 40 kilometers.

The basic mathematics behind the yagi antenna are well understood. To that end, [taste_the_code] used a simple online calculator to determine the correct dimensions to build a yagi out of 2 mm diameter wire that was tuned for the relevant frequency of 868 MHz. The build uses a 3D-printed boom a handle and holes for inserting each individual wire element in the right spot—with little measuring required once the wires are cut, since the print is dimensionally accurate. It was then just a matter of wiring it up to the right connector to suit the gear.

The antenna was tested with a Reyas RYLR998 module acting as a base station, with the DIY yagi hooked up to a RYLR993 module in the field. In testing, [taste_the_code] was able to communicate reliably from 40 kilometers away.

We’ve featured some other unique LoRa antenna builds before, too. Video after the break.

There are a whole bunch of different ways to create 3D scans of objects these days. Researchers at the [UW Graphics Lab] have demonstrated how to use a small, cheap time-of-flight sensor to generate scans effectively.

The key is in how time-of-flight sensors work. They shoot out a distinct pulse of light, and then determine how long that pulse takes to bounce back. This allows them to perform a simple ranging calculation to determine how far they are from a surface or object.

However, in truth, these sensors aren’t measuring distance to a single point. They’re measuring the intensity of the received return pulse over time, called the “transient histogram”, and then processing it. If you use the full mathematical information in the histogram, rather than just the range figures, it’s possible to recreate 3D geometry as seen by the sensor, through the use of some neat mathematics and a neural network. It’s all explained in great detail in the research paper.

The technique isn’t perfect; there are some inconsistencies with what it captures and the true geometry of the objects its looking at. Still, the technique is young, and more work could refine its outputs further.

If you don’t mind getting messy, there are other neat scanning techniques out there—like using a camera and some milk.

Carving pumpkins by hand is hot, sweaty, messy work, and a great way to slice your way into a critical artery. Why not let a water jet do it for you? It’ll be cleaner and more precise to boot, and [Jo_Journey] is here to show us how. 

Obviously, you’ll need a water jet machine, there’s no getting around that. You’ll also still have to do the basic preparation of the pumpkin yourself—cutting a porthole into the top and mucking it out is your job. With that done, you must then mount the pumpkin on two metal rods which will be used to mount it in the water jet machine’s working area.

You can then create a vector file of your design, and use your chosen software to generate the G-code to run the water jet. [Jo_Journey] uses Scribe, and recommends cutting at a speed of around 200 in/min at low pressure. Remember, it’s pumpkin you’re cutting, not high-strength steel.

There is some inaccuracy, of course—your pumpkin’s surface is not a flat plane, after all—but the results are good enough for most Halloween-related purposes. Even despite the geometrical issues, though, [Jo_Journey] shows us that you can get pleasantly sharp edges on your design. That’s very hard to achieve by hand!

We do love a good holiday hack around these parts, even if it’s out of season. If you’ve been cooking up your own pumpkinous plans, don’t hesitate to let us know! Earlier is sometimes better—after all, who has time to hack together a project if you’ve just read about it on October 29?

[Chris Borge] was doing some fine tapping operations, and wanted a better way to position his workpieces. This was critical to avoid breaking taps or damaging parts. To this end, he whipped up a switchable magnetic vice to do the job.

The key to the build is that the magnetic field can be switched on and off mechanically. This is achieved by having two sets of six magnets each. When the poles of both sets of magnets are aligned, the magnetic field is effectively “on.” When the poles are moved to oppose each other, they effectively cancel each other out, turning the field “off.” [Chris] achieved this functionality with 12 bar magnets, 12 M12 nuts, and a pair of 3D-printed rings. Rotating the rings between two alignments serves to switch the set up on or off. The actual switching mechanism is handled with a cam and slider setup which allowed [Chris] to build a convenient vice with a nice large working area. He also took special effort to ensure the device wouldn’t pick up large amounts of ferrous swarf that would eventually clog the mechanism.

It’s a neat build, and one you can easily recreate yourself. [Chris] has supplied the files online for your printing pleasure. We’ve featured some other types of magnetic vise before, too. Video after the break.

Air raid sirens have an important job to do, and have been a critical piece of public safety infrastructure in times of geopolitical turmoil. They sound quite unlike anything else, by virtue of their mechanical method of generating an extremely loud sound output. They’re actually remarkably simple to build yourself, as [MarkMakies] demonstrates.

[Mark’s] build relies almost entirely on 3D printed components and ex-RC gear. The sound itself is generated by a rotor which spins inside a stator. Each is designed with special slots, such that as the rotor turns at speed, it creates spikes of air pressure that generate a loud wail. The rotor and stator are fitted inside a housing with a horn for output, which helps direct and amplify the sound further.

To spin the rotor, [Mark] used a powerful brushless motor controlled by a common hobby speed controller. The actual speed is determined by a potentiometer, which generates pulses to command the speed controller via a simple 555 circuit. By ramping the speed of the motor up and down, it’s possible to vary the pitch of the siren as is often done with real air raid sirens. This action could be entirely automated if so desired.

If you do decide to build such a siren, just be wary about how you use it. There’s no need to go around agitating the townsfolk absent an actual air raid. It’s worth noting that sirens of this type aren’t just used for air raids, either. They’re often used for tornado warnings, too, such as in Dallas, for example. But why not for music?

You can use all kinds of numbers and rating systems to determine whether the air quality in a given room is good, bad, or somewhere in between. Or, like [Makestreme], you could go for a more human visual interface. He’s built a air quality monitor that conveys its information via facial expressions on a small screen.

Named Gus, the monitor is based around a Xiao ESP32-C3. It’s hooked up with the SeeedStudio Grove air quality sensor, which can pick up everything from carbon monoxide to a range of vaguely toxic and volatile gases. There’s also a THT22 sensor for measuring temperature and humidity. It’s all wrapped up in a cute 3D-printed robot housing that [Makestreme] created in Fusion 360. A small OLED display serves as Gus’s face.

The indications of poor air quality are simple and intuitive. As “Gus” detects poor air, his eyelids droop and he begins to look more gloomy. Of course, that doesn’t necessarily tell you what you should do to fix the air quality. If your issue is pollution from outside, you’ll probably want to shut windows or turn on an air purifier. On the other hand, if your issue is excess CO2, you’ll want to open a window and let fresh air in. It’s a limitation of this project that it can’t really detect particulates or CO2, but instead is limited to CO and volatiles instead. Still, it’s something that could be worked around with richer sensors a more expressive face. Some will simply prefer hard numbers, though, whatever the case. To that end, you can tap Gus’s head to get more direct information from what the sensors are seeing.

We’ve seen some other great air quality projects before, too, with remarkably similar ideas behind them. Video after the break.

[Thanks to Willem de Vries for the tip!]

The Nokia 3310 has a reputation of being one of the most indestructible devices ever crafted by humanity. It’s also woefully out of date and only usable in a handful of countries that still maintain a GSM network. It might not be easy to bring it into the 5G era, but you can at least convert it to work with modern chargers, thanks to [Andrea].

If you don’t want to buy the parts, you can just DIY the same mod. [SGCDerek] did just that a few years ago. From what it looks like, you likely don’t even need to worry about doing any fancy charger handshaking. The 3310 will happily grab a charge from a low-current 5V supply straight off the USB pins.

You might think this is a messy, complicated mod, but [Andrea] engineered it as a drop-in upgrade. He’s combined a USB-C port with a small plastic adapter that enables it to sit in place of the original phone’s charge port module.  Contact between the port and the rest of the phone is via spring-loaded contacts. The only additional step necessary is popping out the mic from the original charge module and putting it in the new one. You need only a screw driver to disassemble the phone, swap out the parts, and put it all back together.

If you want to upgrade your own handset, [Andrea] is more than happy to provide the parts for a reasonable price of 25 euros. It’s almost worth it just for the laughs—head around to your friend’s house, ask to borrow a charger, and then plug in your USB-C 3310. You’ll blow some minds.

Once upon a time, it was big news that someone hacked a USB-C port into the iPhone. Video after the break.

The cool thing about the droids of Star Wars is that they’re not that hard to recreate in real life. R2-D2 is a popular choice, but you can even build yourself a neat little BB-8 if you’re so inclined. [Piyush] has built a particularly compelling example that’s transparent, which lets you see the internals and how it all works.

The build makes creative use of a pair of Christmas ornaments. They are perhaps the cheapest and easiest way to source a clear plastic sphere. One serves as the “head”, while the other serves as the larger spherical body. Inside, an Arduino Pro Micro is running the show. It’s hooked up to a L293D motor driver which runs the drive motors and the reaction wheel motor which provides stability, while a separate MOSFET is on hand to run the gear motor which controls the head.

There’s also an HC-05 module for Bluetooth communication, and a BNO055 sensor for motion tracking and ensuring the robot stays the right way up. 3D printed components are used prodigiously to cram everything together tightly enough to fit. There’s even a printed charging base to juice up the little droid. Controlling the robot is as simple as using a smartphone with an app created in the MIT App Inventor.

If you’ve never built a spherical rolling robot before—and few of us have—this design is a great reference for your own work. We’ve seen a few BB-8s over the years, most of which dropped shortly after the movie was released.

If you’re taking any medication, you probably need to take it in a certain dose on a certain schedule. It can quickly become difficult to keep track of when you’re taking multiple medications. To that end, [Mellow_Labs] built an automated pill dispenser to deliver the right pills on time, every time.

The pill dispenser is constructed out of 3D printed components. As shown, it has two main bins for handling two types of pills, controlled with N20 gear motors. The bins spin until a pill drops through a slot into the bottom of the unit, with the drop detected by a piezo sensor. It uses a Beetle ESP32 as the brains of the operation, which is hooked up with a DS1307 real-time clock to ensure it’s dosing out pills at the right time. It’s also wired up with a DRV8833 motor driver to allow it to run the gear motors. The DRV8833 can run up to four motors in unidirectional operation, so you can easily expand the pill dispenser up to four bins if so desired.

We particularly like how the pill dispenser is actually controlled — [Mellow_Labs] used the ESP32 to host a simple web interface which is used for setting the schedule on which each type of pill should be dispensed.

We’ve featured some other pill dispenser builds before, too.

Thanks to [Prankhouz] for the tip!