A Cake Tin Makes A Great Tube Amp Chassis

June 5, 2016 by 44 Comments

If you have ever had a go at building a tube-based project you will probably be familiar with the amount of metalwork required to provide support structures for the tubes themselves and the various heavy transformers and large electrolytic capacitors. Electronic construction sixty years ago was as much about building the chassis of a project as it was about building the project itself, and it was thus not uncommon to see creative re-use of a chassis salvaged from another piece of equipment.

This morning we stumbled upon a rather nice solution to some of the metalwork woes facing the tube constructor courtesy of [Bruce], who built his tube audio amplifier on a chassis made from a cake tin and with its transformers housed in decorative display tins.

The circuit itself is a straightforward single-ended design using an ECL82 triode-pentode on each stereo channel, and comes courtesy of [Nitin William]. The power supply is on-board, and uses a pair of silicon diodes rather than another tube as the rectifier.

It’s true that [Bruce] has not entirely escaped metalwork, he’s still had to create the holes for his tubes and various mountings for other components. But a lot of the hard work in making a tube chassis is taken care of with the cake tin design, and the result looks rather professional.

We have something of a personal interest in single-ended tube amplifiers here at Hackaday, as more than one of us have one in our constructional past, present, or immediate futures. They are a great way to dip your toe in the water of tube amplifier design, being fairly simple and easy to make without breaking the bank. We’ve certainly featured our share of tube projects here over the years, for example our “Groove tube” round-up, or our look at some alternative audio amplifiers.

CNC Drag Knife Upgrade With Off-the-Shelf Blades

June 5, 2016 by 20 Comments

Drag Knives seem to be the overshadowed awkward kid on the playground of CNC equipment, but they have a definitive niche making stencils, vinyl stickers, and paper cuts. Unfortunately, the drag knife blades for CNC routers are pricey — over $100 for a single blade. [Brian] at the Grunblau Design Studio took the price point as a challenge to build his own end-effector. A few iterations later, he’s created his very own drag knife blade tool that accepts replaceable steel blades for cutting.

From constraint-driven concept, to a 3D printed proof-of-concept, to a fully machined aluminum prototype, [Brian’s] efforts hit all the highlights of a well-engineered project. At the end of the day, dull blades can be swapped for a few dollars, rather than shelling out another $150 for the off-the-shelf variant. We’ve seen bootstrapped CNC vinyl cutters before, but nothing that takes an original re-envisioning of the tool itself.

In Soviet Russia, DIY Laser Rangefinder Scan YOU!!

June 5, 2016 by 40 Comments

Yakov Smirnoff used to say, “In America, you can always find a party. In Soviet Russia, Party finds YOU!!” Only here, it’s a laser rangefinder.

In this project (automatic translation), [iliasam] makes his own scanning laser rangefinder, like the ones that we’ve seen in fancy vacuum cleaners. But he does it from scratch.

b91e3927436e885627e52179a5ed6c70While this sort of thing is easy if you have a webcam and a ton of processing power to throw at it, [iliasam] takes the hard way out — measuring the parallax of the reflected spot through a lens on a linear image sensor (which renders as “photodetector line” in translated Russian).

Linear image sensors are a lot like the elements in your CMOS digital camera, with the exception that the elements are arranged in a line instead of a plane, and they’re a lot easier to interface with a microcontroller. Hold a data line high to take an exposure, and then clock out the (analog) voltage values that correspond to the amount of light that hit each cell in the line array. While [iliasam] paid an estimated $18 for his, we’ve found them much cheaper on eBay. And there’s usually a linear sensor, often RGB and complete with driver circuitry, in a scanner if you take one apart. This could be done for just a few bucks if you were thrifty.

Continue reading “In Soviet Russia, DIY Laser Rangefinder Scan YOU!!” →

How An Amiga Graphics Business Ran In The 1990s

June 5, 2016 by 37 Comments

If you have ever used an eraser to correct a piece of pencil work, have you ever considered how much of an innovation it must have seemed when the first erasers were invented? It might seem odd to consider a centuries-old piece of stationery here on Hackaday, but there is a parallel in our own time. Digital image manipulation is such a part of everyday life these days as to have become run-of-the-mill for anyone with a mobile phone and the right app, but it’s easy to forget how recent an innovation it really is. Only a few decades ago your only chance of manipulating a photograph was to spend a lot of time in a darkroom with a photographic developer of exceptional skill, now children who have never known a world in which it wasn’t possible can manipulate their selfies with a few deft touches of the screen.

[Steve Greenfield] pointed us at a detailed description of the business he ran in the 1990s, offering digital and composite photography using an upgraded Amiga 3000.  It caught our attention as a snapshot of the state of digital image manipulation when these things still lay at the bleeding edge of what was possible.

His 3000 was highly customised from the stock machine. It featured a Phase 5 68060 accelerator board, a Cybervision 64 graphics card, a then-unimaginably-huge 128MB RAM, and an array of gigabyte-plus Fast SCSI drives.  To that he had attached a Polaroid SCSI digital camera with a then-impressive 800×600 pixel resolution. The Polaroid had no Amiga drivers, so he ran the Shapeshifter Mac emulator to capture images under the MacOS of the day. The fastest 68000-series Mac only had a 68040 which the early PowerPC Macs could only emulate, so he writes that his 68060-equipped Amiga ran the Mac software faster than any Mac at the time.

His stock-in-trade was attending sci-fi conventions and giving costumed attendees pictures with custom backgrounds, something of a doddle on such a souped-up Amiga. He writes of the shock of some Microsoft employees on discovering a 60MHz computer could run rings round their several-hundred-MHz Pentiums running Windows 95.

His business is long gone, but its website remains as a time capsule of the state of digital imagery two decades ago. The sample images are very much of their time, but for those used to today’s slicker presentation it’s worth remembering that all of this was very new indeed.

In a world dominated by a monoculture of Intel based desktop computers it’s interesting to look back to a time when there was a genuine array of choices and some of them could really compete. As a consumer at the start of the 1990s you could buy a PC or a Mac, but Commodore’s Amiga, Atari’s ST, and (if you were British) Acorn’s ARM-based Archimedes all offered alternatives with similar performance and their own special abilities. Each of those machines still has its diehard enthusiasts who will fill you in with a lengthy tale of what-if stories of greatness denied, but maybe such casualties are best viewed as an essential part of the evolutionary process. Perhaps the famous Amiga easter egg says it best, “We made Amiga … ”

Here at Hackaday we’ve covered quite a few Amiga topics over the years, including another look at the Amiga graphics world. It’s still a scene inspiring hardware hackers, for example with this FPGA-based Amiga GPU.

Amiga 3000 image: By [Joe Smith] [Public domain], via Wikimedia Commons.

Learning ARM Without Dev Board

June 5, 2016 by 25 Comments

There’s a tremendous amount of value in using pre-built, known-good development environments. It saves you hours of potential headaches when things aren’t working. Is the bug in the hardware or the software? If you bought a dev kit, you can be pretty sure it’s your software. But sometimes using a dev kit also feels like there’s a black box in the system. [Kevin] wanted to peer inside the black box, so he ordered a tray of cheap STM32F103 chips on eBay, and did the rest himself.

“The rest” isn’t all that much, but figuring that out is half the battle. [Kevin] soldered the TQFP chip onto a breakout board, added some decoupling capacitors, and connected four pins up to a dirt-cheap ST-Link programmer clone. The rest of the article describes the toolchain he used to compile for and program the chip. The end result is, natch, a blinking LED.

If you’re a bit experienced with microcontrollers and want to dive head-first into an ARM chip, [Kevin]’s writeup is just the ticket. In a single (long) blog post, he walks you through all the steps. If this is your first rodeo, you might be tempted to cheese out and buy a pre-built board on eBay (search “STM32F103” and you’ll find many options to choose from) and we don’t think that’s a bad idea either. Still, there’s just something to be said for the confidence that you’ll have once you’ve built the whole system from scratch.

FabLab Hackathon Gives The Gift Of Art Back To A Stranger In Need

June 5, 2016 by 3 Comments

If building the James Webb Space Telescope and F/A-18 fighter jets aren’t enough reasons to work for Northrop Grumman, there’s always the FabLab – the company sponsored hackerspace. It’s a place where anything goes and everything is possible, including giving the gift of art back to a stranger in need.

The video below tells the story of [Raul Pizarro], a young man and gifted artist. Diagnosed as a child with muscular dystrophy, [Raul] was getting to the point where the progressive weakening of his muscles was making it difficult to hold up his arm. [Raul]’s art was slipping away – until [Tony Long] caught wind of the story, that is. [Tony] runs the FabLab, and once he put out the word to his colleagues he got a hackathon together to work on solutions for [Raul].

What they came up with was an overhead support system with a tool balancer and custom articulated sling to reduce the effect of gravity and support [Raul]’s arm. To compensate for his reduced range of motion, they also built an easel with actuators that can raise and lower his canvases and position them where he needs them. It looks like the FabLab team paid special attention to making everything as smooth and stable as possible, and as a result [Raul] is back to doing what he does best. Oh, and if [Tony] and the FabLab sound familiar, it might be because he played host when our own [Mike Szczys] visited Northrop last year.

We really like to see hacks that help mankind as a whole, but there’s something special about a bunch of strangers coming together to help just one man too. Hats off to [Tony] and his FabLab team for pulling off a great hack and giving [Raul] back his art.

Continue reading “FabLab Hackathon Gives The Gift Of Art Back To A Stranger In Need” →

Hackaday Prize Entry: A Numerically Controlled RepRap

June 4, 2016 by 14 Comments

The story for permanent storage for computers begins with the Jacquard loom. Hackaday commenters that are less clever than a Wikipedia article may argue that it was the earlier Bouchon and de Vaucanson looms, but either way we owe permanent storage methods to loom designers. So the story goes that punched cards for weaving brocades and damask patterns in cloth turned into punched cards for tabulating a census, calculating artillery trajectories, and ends with hundreds of gigabytes of storage in a thumbnail-sized micro SD card.

This story glosses over one important fact. The automated looms of the 17th century were simply a way to make a manufacturing process faster. These automated looms were the forebears of numerically controlled machine tools. These machines, first a lathe, followed by mills and all sorts of metalworking tools, first appearing in the 1950s, used punched tape to store the commands required to mill a part out of metal. Just like the SD card on a modern 3D printer.

For [will.stevens’] Hackaday Prize entry, he’s going back to the roots of automated manufacturing and building a punched card reader for his 3D printer. Is the idea sound? Yes. Is it going to be easy? No, [will] is creating his punched card reader on his 3D printer. It’s the ultimate expression of the RepRap philosophy of self-replication, and an interesting engineering challenge, too.

[will]’s idea for a punch card print controller uses relays. It’s a simple control system that encodes the individual steps for the X and Y axes, along with a length of a line. This printer won’t be able to create lines that go in every direction, instead, there are only 48 possible angles this printer can use out of 360 degrees. At large scales, prints and plots will have the jaggies, but at smaller scales, this control system will be able to print something resembling a circle.

[will] has a PDF of his proposed control system, and he’s already hard at work creating the 3D printed relays and solenoids. [will]’s goal for this year’s Hackaday Prize is to create a 2D plotter – just one axis short of a 3D printer, and he’s well on his way to printing off his own punched cards.

The HackadayPrize2016 is Sponsored by: