A Fast Linear Actuator Entirely In One PCB

August 10, 2022 by Jenny List 18 Comments

There are many ways to make a linear actuator, a device for moving something is a straight line. Most of the easier to make ones use a conventional motor and a mechanical linkage such as a rack and pinion or a lead screw, but [Ben Wang] has gone for something far more elegant. His linear actuator uses a linear motor, a linear array of coils for the motor phases, working against a line of magnets. Even better than that, he’s managed to make the whole motor out of a single PCB. And it’s fast!

This represents something of an engineering challenge, because achieving the required magnetic field from the relatively few turns possible on a PCB is no easy task. He’s done it by using a four-layer board to gather enough turns for the required magnetic field, and a simple view of the board doesn’t quite convey what lies beneath.

PCB motors are perhaps one of those areas where the state of the art is still evolving, and the exciting part is that their limits are being pushed right there in our community. And this isn’t the only linear motor we’ve seen recently either, here’s one used in a model train.

What Goes Into A Hacker Camp

August 10, 2022 by Jenny List 10 Comments

Long-time readers of Hackaday will know that we attend quite a few events, including summer hacker camps. Here in Europe this year there are two large events, the British Electromagnetic Field, and the Dutch MCH, or May Contain Hackers. These events are put together by volunteers from within the community, and as part of the MCH setup I noticed they needed drivers for their off-site logistics. I have a licence to drive medium-sized trucks in Europe so it seemed like a perfect fit. I traveled early on the first set-up day to the Dutch city of Utrecht, and found myself behind the wheel of a large Volkswagen box van. My brief career as a trucker had begun!

An Empty Field Of Dreams

A field with a few tents and a blue sky — The tents stand in isolation at the end of day one.

The Netherlands is a relatively small country and the MCH site at Zeewolde is roughly in its centre, so while the traffic could be heavy the distances weren’t large by American or even British standards. There were however a wide variety of loads waiting for me and my fellow driver, and a few obstacles such as the hottest days of the year and angry Dutch farmers blockading the roads. If you’re interested in the logistics behind a large hacker camp then our journeys provided an insight that maybe wandering around the field doesn’t quite deliver.

Arriving on site on the first day gives a perspective on how much of the infrastructure comes from specialist contractors and thus isn’t delivered by the hackers. Articulated trucks from the marquee company were disgorging the main tents, with their crews expertly assembling them in record time. The toilets and showers were arriving as self-contained hook lift container units, and yet more contractors were delivering fencing or tables and chairs. I can add the power infrastructure to this list, but due I’m told to delays at another event this wasn’t on site on the first day. Continue reading “What Goes Into A Hacker Camp” →

A Steam Box For Not A Lot

August 10, 2022 by Jenny List 21 Comments

If you have ever marveled at the complex wooden curves used by shipbuilders or some furniture makers, then you have probably at some point hankered after a steam box. This is as its name suggests, a chamber in which a piece of wood is steamed until it becomes flexible, at which point it can be pressed into a new shape that it will retain once cooled. The ever-resourceful [Xyla Foxlin] shows us how to make a steam box using easy-to-find parts, as can be seen in the video below the break.

The steam supply comes from a commercial steam boiler of the type used by decorators for wallpaper stripping, and the steam box itself is made from a length of PVC pipe. Inside the pipe are a series of aluminium dowels that form a rack upon which the wood sits away from any condensation, and the whole things sits at a slant with the steam inlet and a condensation drain at the bottom end.

In use, a piece of wood is loaded into the tube and steamed, before being bent using a set of forms in a vice. The process looks straightforward enough that even we could give it a go, so we’re sure Hackaday readers will find it interesting.

We think this may be the first steam box we’ve brought you, but it’s not the first time we’ve discussed bending wood.

Continue reading “A Steam Box For Not A Lot” →

Hackaday Prize 2022: A Plasma Tweeter For Ultimate Clarity

August 8, 2022 by Jenny List 18 Comments

In the world of audio there are a huge variety of esoteric technologies which are rarely seen. One such is the plasma tweeter, a type of loudspeaker which generates sound by modulating a small electrical discharge. The benefit of this design comes in its delivering the closest possible to a point audio source, in effect the theoretical ideal speaker for treble frequencies. They’re a little hazardous due to the voltage but aren’t too difficult to make, as demonstrated by [Mircemk] whose version uses a recycled power pentode tube — which is how it showed up in the Hack it Back round of the Hackaday Prize.

It can be thought of as a cousin of the Tesla coil, with the same resonant oscillator but no capacity hat. Instead the top of the coil ends in a point, from which in the perfect speaker a ball of plasma replaces the Tesla’s impressive sparks. In this case the pentode is joined by a high-voltage TV line output transistor as a bias supply, which is in turn modulated with the audio through a small amplifier. It sometimes needs the plasma teasing out of it through discharge to a screwdriver, but the result is a very effective and clear plasma tweeter.

If plasma tweeters interest you, we’ve featured them before.

Was There A Programmable PONG Chip?

August 8, 2022 by Jenny List 19 Comments

Students of game console history will reach back into the 1970s for the primordial machines, tracing from the Magnavox Odyssey onwards, and thence via the Fairchild Channel F into the world of microprocessors and the chain of machines that lead us to those we enjoy today. In the early days there was a parallel evolution for a few years of dedicated video game consoles with no interchangeable cartridges or microprocessors, these took their inspiration from the legendary PONG arcade game and used dedicated non-programmable hardware in custom chips to create their video. But was there a programmable PONG chip lurking among all the others? [Old VCR] takes a look.

Many readers will be familiar with MOS Technology as the originator of the 6502 processor used in so many 8-bit home computers. But perhaps many of our attention spans will have passed over another of their products, the MOS 7600 and 7601. These were the chip company’s entry into the surprisingly congested mid-70s PONG-in-a-chip market, and the article investigates the question of whether they might in fact be mask-programmed microcontrollers masquerading as dedicated chips.

It’s a fascinating tour through the mid-70s in terms of games consoles, MOS, and through their eventual takeover, Commodore. The possibility of a mask-programmed PONG chip is explored in detail and discounted, though like [Old VCR], we’d love to see one decapped and reverse engineered. For us a stronger line of evidence comes in asking why MOS would stop at PONG if they had a mask-programmed microcontroller in their catalogue, and that our not having seen MOS microcontrollers appearing all over Commodore’s subsequent products suggests that it may be simply another dedicated PONG chip like all the others.

We’ve seen quite a few variants of this iconic game over the years, but few as impressive as one made from discrete components.

Hackaday Prize 2022: DIY Brushless Hand Cranked Generator

August 6, 2022 by Jenny List 12 Comments

A standard part of travel kit for the 2020s is now a battery pack — a hefty lithium-ion cell with onboard electronics for USB charging, that ensures all of our devices stay topped up while we’re out of range of a socket. But what happens when there is no handy mains supply to recharge it from? Step in [Chleba], with a hand cranked generator.

There are plenty of hand cranked generators to be found online, from tiny devices intended to top up a single phone to sturdy metal boxes intended for battery charging. This one differs from those in that most use a brushed DC motor as a cheap generator, while here that function comes from a stepper motor feeding a rectifier pack and thence a DC-to-DC converter. A step-up gearbox provides the necessary shaft speed, and a neat 3D-printed case rounds everything off.

The result is about as neat a generator as you could imagine, and would certainly be of use shoved into any off-grid backpack. Meanwhile it’s not the first we’ve shown you, we’ve even see one that could start a car.

Buzzword Bingo Bitcoin Burial Burrowing Blueprint Balked At By Bureaucracy

August 4, 2022 by Jenny List 46 Comments

Many of you will at some time have heard the unfortunate tale of [James Howells], a Welsh IT worker who threw away a hard drive containing 8,000 Bitcoin back in 2013. Over the years he’s hatched various schemes to persuade his local council to let him dig up the landfill where it’s reputed to be buried, and every time he’s been rebuffed. Despite the fall in the price of cryptocurrencies he’s back with another. With the added spice of AI and robot dogs alongside the cryptocurrency angle, it reads like a buzzword bingo card and adds a whole new meaning to “Bitcoin mining”. Seemingly despite generous offers the local council are still not keen on letting him dig for the drive.

We can’t help feeling sorry for the guy — after all, in the early days of cryptocurrency the coins were a worthless curiosity so it’s not impossible there are readers with similar stories. But we’re curious how well the drive will have survived its 9-year interment even if the AI robot arm and robot dog security would ensure its recovery. With that much cash at stake the best in the data recovery business will no doubt be unleashed on whatever remains they might recover, but in the unfriendly environment of a festering landfill we’d be curious as to whether chemical action might have corroded the platters to the point at which nothing might remain. Wales has a high rainfall unlike the American southwest, so we doubt it would survive as well as an Atari cartridge.

Meanwhile, tell us your cryptocurrency might-have-beens in the comments.

Landfill Site sign by Geographer, CC BY-SA 2.0.