classic hacks

2667 Articles

Building A Foam Machine From A Leaf Blower And A Water Pump

June 28, 2019 by 24 Comments

Imagine a tub overflowing with bubble bath, except it’s a club dancefloor and music is pumping all night. This is what is known as a “foam party” — a wild and exciting concept that nonetheless many are yet to experience. The concept exploded in popularity in Ibiza in the 1990s, and foam parties are regularly held at nightclubs and festivals the world over.

Foam is generated with the obviously-named foam machine, and these can be readily purchased or hired for anyone wishing to host such an event. However, that’s not the hacker way. If you’re a little ingenious and take heed of the safety precautions, here’s how you can do it yourself.

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Nuclear Reactor Simulator Is The Project Of A Lifetime

June 27, 2019 by 39 Comments

Have you been watching Chernobyl? Well, so has everyone else. Right now it seems the whole Internet is comprised of armchair dosimetrists counting roentgens in their sleep, but [Mark Wright] doesn’t need a high-budget TV show to tell him about the challenges of wrangling the atom with 1980s technology. He’s done it for real. His memories of working at a Westinghouse Pressurized Water Reactor over 30 years ago are so sharp that he’s been building a nuclear reactor “simulator” running on the Raspberry Pi that looks nearly as stressful as sitting in control room of the real thing.

The simulator software is written in Python, and is responsible for displaying a simplified overview of the reactor and ancillary systems on the screen. Here all the information required to operate the “nuclear plant” can be seen at a glance, from the utilization of individual pumps to the position of the control rods.

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Replacement Batteries For The Sony Discman

June 27, 2019 by 24 Comments

Some of the first Sony Discmans included rechargeable batteries. These batteries were nickel metal hydride batteries (because of the technology of the time) and are now well past their service life. The new hotness in battery technology is lithium — it offers greater power density, lighter weight, and a multitude of ready-to-go, off the shelf cells. What if someone were to create a new battery pack for an old Sony Discman using lithium cells? That’s exactly what [sjm4306] did for their entry into this year’s Hackaday Prize.

The Discman [sjm] is working with uses a custom, Sony-branded battery based on NiMH technology with a capacity of around 500 mAH. After carefully measuring the dimensions of this battery, it was replicated in plastic with a 3D printer. This enclosure was then stuffed with a small lithium cell scavenged from a USB power bank.

The only tripping points for this build were the battery contacts. The originally battery had two contacts on the end that fit the Discman exactly; these were replicated with a small PCB wired up to the guts of the USB powerbank. The end result is a direct, drop-in replacement for the original Discman battery with a higher capacity, that’s also rechargeable via USB. It’s a fantastic project, with the entire build video available below.

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Testing Brushless Motors With A Little Help From The ESC

June 27, 2019 by 6 Comments

These days, brushless motors are the go-to for applications requiring high power in a compact package. It’s possible to buy motors in all manner of different configurations off the shelf, and the range available is only getting better. However, sometimes getting something truly optimal requires a bit of customization. With motors, this can involve swapping magnets or hand-winding coils. In these cases, it can be useful to test the modified motor to determine its performance. [JyeSmith]’s ESC tester is capable of just that.

Fundamentally, the ESC tester is a simple piece of hardware. It uses a microcontroller to speak the Dshot protocol. This protocol is typically used to communicate between multi-rotor flight controllers and ESCs. In this case, the Dshot telemetry is instead displayed on a small OLED screen. This enables the user to read off KV values, as well as other useful data such as current draw and RPM. This can help quantify the effects of any modifications made to a motor, as well as prove useful for learning about parts of spurious origins.

It’s a device that should prove useful to those trying to eke out every last drop of performance from their multi-rotor builds. We expect to see more similar projects emerge as drone racing continues to increase in popularity. If you’re still trying to learn the theory behind the technology, you can always build your own brushless motor. Video after the break.

[Thanks to Keegan for the tip!]

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PackProbe Reports Laptop Battery Health

June 26, 2019 by 11 Comments

The 18650 cell has become a ubiquitous standard in the lithium battery world. From power drills to early Tesla vehicles, these compact cells power all manner of portable devices. A particularly common use is in laptop batteries, where they’re often built into a pack using the Smart Battery System. This creates a smart battery that can communicate and report on its own status. PackProbe is a software tool built to communicate with these batteries, and you might just find it comes in handy.

The code runs on the WiFi-enabled Arduino Yún by default, but can be easily modified to suit other Arduino platforms. Communicating over SMBus using the Arduino’s I2C hardware, it’s capable of working with the vast majority of laptop batteries out there which comply with the Smart Battery System. With that standard being minted in 1994, it’s spread far and wide these days.

It’s a great way to harvest not only the specifications and manufacturing details of your laptop battery pack, but also to check on the health of the battery. This can give a clear idea over whether the battery is still usable, as well as whether the cells are worth harvesting for those in the recycling business.

You’re not limited to just the Arduino, though. There’s a similar tool available for the ESP8266, too.

Ink-Dipping Machine Saves Iotas Of Time

June 26, 2019 by 11 Comments

[Uri Tuchman] doesn’t always write with a dip pen. But when he does, he gets tired of re-inking it almost immediately. Now, convenience comes in many forms. He could make the switch to any number of modern writing instruments, sure. But that would be throwing out the baby with the bathwater.

[Uri] decided that old-timey problems call for old-timey solutions, and we couldn’t agree more. His machine is an amazingly well-crafted automaton that dips a handmade pen into ink and shakes off the excess with the turn of a crank and the nudging of cams. We love the hand-carved claw, which looks perfectly absurd as it moves about gracefully on custom brass hinges.

We were somewhat surprised that given all this work, [Uri] didn’t grind his own nib or make his own ink. But that would cut down on the time he has to write letters longhand in between waiting for a wet quill. Crank past the break to see [Uri]’s thoroughly entertaining build video for this awe-inspiring machine.

Mesmerized by automatons? This laser-cut water droplet wave should quench your thirst.

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A Rough And Ready Pan & Tilt Mirror

June 25, 2019 by 8 Comments

There’s nothing quite like waking up on a warm and sunny morning, with the sun filtering in through the windows over a magnificent beach view. Of course, in real life, not every bedroom has access to beautiful natural vistas and abundant natural light. [Rue Mohr] decided to try and solve this issue with technology.

The initial write-up may be brief, but the pictures of the resulting project show a proper hacker’s build. A stand for an old office chair appears to serve as the base, and the mirror is mounted on a frame that allows for both pan and tilt to be adjusted. There’s a large gear to enable pan rotation, which meshes with a nifty old-school cage gear built out of what we suspect is plastic and welding rod. An AVR microcontroller is charged with running the show, with it interpolating a series of waypoints to set the mirror’s position throughout the day.

[Rue] reports that the project is nearing completion, and is soon to be fully automated. With the dark bedroom that spawned the project no longer a concern, the mirror will instead be pressed into service to provide sun to a row of bean plants.

If you’re looking for a pan-tilt mechanism, but something a little smaller, this 3D-printed mechanism might be just what you’re after.