A Paintball Turret Controlled Via Xbox Controller

November 4, 2025 by 7 Comments

Video games, movies, and modern militaries are all full of robotic gun turrets that allow for remotely-controlled carnage. [Paul Junkin] decided to build his own, albeit in a less-destructive paint-hurling fashion.

The turret sits upon a lazy susan bearing mounted atop a aluminium extrusion frame. A large gear is mounted to the bearing allowing the turret to pan when driven by a stepper motor. A pair of pillow block bearings hold a horizontal shaft which mounts the two paint markers, which again is controlled by another stepper motor to move in the tilt axis. An ESP32 microcontroller is responsible for running the show, panning and tilting the platform by commanding the large stepper motors. Firing the paintball markers is achieved with solenoids mounted to the triggers, which cycle fast enough to make the semi-auto markers fire in a way that almost feels like full-auto. Commanding the turret is via an Xbox One controller; communicating with the ESP32 over Bluetooth using the BluePad32 library.

It’s worth noting you shouldn’t shoot paintballs at unsuspecting individuals, since they can do extreme amounts of damage to those not wearing the proper protection. We’ve featured a great many other sentry guns over the years, too, like this impressive Portal-themed build. Video after the break.

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Print in place pump being used next to ladder

Print In Place Pump Pushes Limits Of Printing

November 4, 2025 by 5 Comments

3D printing has taken off into the hands of almost anyone with a knack for wanting something quick and easy. No more messing around with machining or complex assembly. However, with the general hands-off nature of most 3D prints, what could be possible with a little more intervention during the printing process? [Ben] from Designed to Make represents this perfectly with an entire centrifugal pump printed as one.

This project may not entirely fit into the most strict sense of “print in place”; however, the entire pump is printed as one print file. The catch is the steps taken during printing, where a bearing is placed and a couple of filament changes are made to allow dissolvable supports to be printed. Once these supports are dissolved away, the body is coated with epoxy to prevent any leakage.

Testing done by [Ben] showed more than impressive numbers from the experimental device. Compared to previous designs made to test impeller features, the all in one pump could stand its own against in most categories.

If you want to check out the project yourself, check out the Hackaday project here. One of the greatest parts of the open source 3D printing world is the absolute freedom and ingenuity that comes out of it, and this project is no exception. For more innovations, check out this DIY full color 3D printing!

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2025 Component Abuse Challenge: Weigh With A TL074

November 4, 2025 by 17 Comments

The late and lamented [Bob Pease] was one of a select band of engineers, each of whose authority in the field of analogue integrated circuit design was at the peak of the art. So when he remarks on something in his books, it’s worth taking notice. It was just such an observation that caught the eye of [Trashtronic]; that the pressure on a precision op-amp from curing resin could be enough to change the device’s offset voltage. Could this property be used for something? The op-amp as a load cell was born!

The result is something of an op-amp torture device, resembling a small weighing machine with a couple of DIP-8 packages bearing the load. Surprisingly modest weights will change the offset voltage, though it was found that the value will drift over time.

This is clearly an experimental project and not a practical load cell, but it captures the essence of the 2025 Component Abuse Challenge of which it forms a part. Finding completely unexpected properties of components doesn’t always have to lead to useful results, and we’re glad someone had done this one just to find out whether or not it works. You still just about have time for an entry yourself if you fancy giving it a go.

2025 Hackaday Component Abuse Challenge

Jenny’s Daily Drivers: ReactOS 0.4.15

November 4, 2025 by 25 Comments

When picking operating systems for a closer look here in the Daily Drivers series, the aim has not been to merely pick the next well-known Linux distro off the pile, but to try out the interesting, esoteric or minority OS. The need remains to use it as a daily driver though, so each one we try has to have at least some chance of being a useful everyday environment in which a Hackaday piece could be written. With some of them such as the then-current BSD or Slackware versions we tried for interest’s sake a while back that’s not a surprising achievement, but for the minority operating systems it’s quite a thing. Today’s choice, ReactOS 0.4.15, is among the closest we’ve come so far to that ideal.

For The N’th Time In The Last 20 Years, I download A ReactOS ISO

A Windows-style ReactOS desktop with a web browser showing Hackaday
It’s fair to say there are still a few quirks, but it works.

ReactOS is an open-source clone of a Windows operating system from the early 2000s, having a lot on common with Windows XP. It started in the late 1990s and has slowly progressed ever since, making periodic releases that, bit-by-bit, have grown into a usable whole. I last looked at it for Hackaday with version 0.4.13 in 2020, so have five years made any difference? Time to download that ISO and give it a go.

Installing ReactOS has that bright blue and yellow screen feeling of a Windows install from around the millennium, but I found it to be surprisingly quick and pain free despite a few messages about unidentified hardware. The display driver it chose was a VESA one but since it supported all my monitor’s resolutions and colour depths that’s not the hardship it might once have been. Continue reading “Jenny’s Daily Drivers: ReactOS 0.4.15” →

Rocket Roll Control, The Old Fashioned Way

November 4, 2025 by 14 Comments

The vast majority of model rockets go vaguely up and float vaguely downwards without a lot of control. However, [newaysfactory] built a few rockets that were altogether more precise in their flight, thanks to his efforts to master active roll control.

[newaysfactory] started this work a long time ago, well before Arduinos, ESP32s, and other highly capable microcontroller platforms were on the market. In an era when you had to very much roll your own gear from the ground up, he whipped up a rocket control system based around a Microchip PIC18F2553. He paired it with a L3G4200D gyro, an MPXH6115A barometer, and an MMA2202KEG accelerometer, chosen for its ability to provide useful readings under high G acceleration. He then explains how these sensor outputs were knitted together to keep a rocket flying straight and true under active control.

[newaysfactory] didn’t just master roll control for small rockets; he ended up leveraging this work into a real career working on fully-fledged autopilot systems. Sometimes your personal projects can take your career in interesting directions.

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Lithium-Ion Batteries: WHY They Demand Respect

November 4, 2025 by 59 Comments

This summer, we saw the WHY (What Hackers Yearn) event happen in Netherlands, of course, with a badge to match. Many badges these days embrace the QWERTY computer aesthetic, which I’m personally genuinely happy about. This one used 18650 batteries for power, in a dual parallel cell configuration… Oh snap, that’s my favourite LiIon cell in my favourite configuration, too! Surely, nothing bad could happen?

Whoops. That one almost caught me by surprise, I have to shamefully admit. I just genuinely love 18650 cells, in all glory they bring to hardware hacking, and my excitement must’ve blindsided me. They’re the closest possible entity to a “LiIon battery module”, surprisingly easy to find in most corners of this planet, cheap to acquire in large quantities, easy to interface to your projects, and packing a huge amount of power. It’s a perfect cell for many applications I and many other hackers hold dear.

Sadly, the 18650 cells were a bad choice for the WHY badge, for multiple reasons at once. If you’re considering building a 18650-based project, or even a product, let me show you what exactly made these cells a bad fit, and how you might be able to work around those limitations on your own journey. There’s plenty of technical factors, but I will tell you about the social factors, because these create the real dealbreaker here. Continue reading “Lithium-Ion Batteries: WHY They Demand Respect” →

Making Audible Sense Of A Radiation Hunt

November 4, 2025 by 17 Comments

The clicking of a Geiger counter is well enough known as a signifier of radioactive materials, due to it providing the menacing sound effect any time a film or TV show deals with radiation. What we’re hearing is the electronic detection of an ionization event in a Geiger-Muller tube due to alpha or beta radiation, which is great, but we’re not detecting gamma radiation.

For that a scintillation detector is required, but these are so sensitive to background radiation as to make the clicking effect relatively useless as an indicator to human ears. Could a microcontroller analyse the click rate and produce an audible indication? This is the basis of [maurycyz]’s project, adding a small processor board to a Ludlum radiation meter.

When everything sounds like a lot of clicks, an easy fix might be to use a divider to halve the number and make concentrations of clicks sound more obvious. It’s a strategy with merit, but one that results in weaker finds being subsumed. Instead the approach here is to take a long-term background reading, and compare the instantaneous time between clicks with it. Ths any immediate click densities can be highlighted, and those which match the background can be ignored. SO in goes an AVR128 for which the code can be found at the above link.

The result is intended for rock prospecting, a situation where it’s much more desirable to listen to the clicks than look at the meter as you scan the lumps of dirt. It’s not the first project in this line we’ve brought you, another one looked at the scintillation probe itself.