The World’s Supply Of DB-19 Connectors

[Steve] over at Big Mess O’ Wires has a very, very niche product. It’s the Floppy Emu, a hard disk emulator for the Apple II, Lisa, and very old Macs. The Floppy Emu takes data stored on an SD card and presents it to these classic computers through a contemporary connector, the venerable DB-19. This connector is in the same family as the familiar DB-25 parallel port, DE-9 serial port and the old DA-15 joystick port, but there’s something very special about the DB-19 connector – nobody makes it anymore, and no surplus electronics store has any in stock. They’re unobtanium, and when you’re making a product built around this connector, you’re going to have a few problems.

Those problems have come to a head over the past year, but getting a few thousand DB-19 connectors manufactured has always seemed just out of reach. It would be a five-figure investment for a very niche product, and [Steve] would have to find someone to make the connectors.

The world’s shortage of DB-19 connectors is no more. After chatting up a few people in the NeXT and Atari communities, [Steve] set up a group buy and manufactured the first batch of DB-19 connectors in recent memory. The world’s supply of DB-19 connectors, all 10,000 of them, is now in [Steve]’s living room.

The process of manufacturing ten thousand DB-19 connectors actually wasn’t that hard for [Steve]. Over the past year, he’s reached out to manufacturers to get a quote, and he still had those numbers in his rolodex. The only problem was finding an engineering drawing of a DB-19 connector and transferring a large amount of money to Hong Kong. The drawing was easy enough, as datasheets sometimes last longer than the parts they describe. Transferring the money over to the manufacturer meant convincing a bank manager there is not a Nigerian prince in Hong Kong and thirty minutes of paperwork.

After a few months, a round of prototyping, and a trip through customs, the world’s supply of DB-19 connectors finally landed on [Steve]’s porch. He still needs to ship them out to the NeXT and Atari folk who participated in the group buy, but the great shortage of DB-19 connectors is over for now.

Hackaday Links: June 5, 2016

CERN is having a hackathon. It’s in October, yes, but the registration is closing on the 15th of June. They’ve been doing this every year, and the projects that come out of this hackathon are as diverse as infrastructure-less navigation, cosmic ray detectors, and inflatable refrigerators.

Have one of those solder fume extractors? Here’s an obvious improvement. [polyglot] put a strip of LEDs around the frame of his solder fume extractor to put a little more light on the subject.

A few months ago, [Bunnie] started work on a book. It was the Essential Guide to Electronics in Shenzhen. It’s made for hardware hackers to figure out how to buy stuff in Shenzhen, using a neat point-and-understand interface. Those books are now being shipped to people around the globe. I got one, and here’s the mini-review: it’s awesome. Is it a complete travel guide? No, but if you dropped me off at Hong Kong International, I could probably 1) Make it to Shenzhen 2) Buy random LEDs 3) Find a hotel 4) Get a beer 5) Not die. Pics below.

You’re hackers, and that means you’re the people who build stuff for all those ‘makers’ out there. Don’t have an MBA? No problem, [Dave Jones] has your back. He re-did his Economics of Selling Hardware video from several years ago. It’s 25 minutes long, and gives you enough information so you’re not a complete idiot at the business end of design.

Like Raspberry Pis stuffed into things? Here’s a Pi Zero stuffed into a MegaDrive cartridge. Now someone grab a Sonic and Knuckles cart, build a ROM reader, and do a proper cart-reading emulator.

If you’re into R/C, you know about Flite Test. They’re the folks that make crazy, crazy model planes out of Dollar Tree foam board, and have gotten hundreds of people into the hobby. Flite Test is having their own con, Flight Fest, in a little over a month. It’s in Ohio, and from last year’s coverage of the event, it looks like a really cool time.

So, No Man’s Sky is coming out soon. It’s a space game set in a procedurally generated, infinite galaxy. Does anyone have any idea on how to form a Hackaday clan? Somebody should start a Hackaday clan/alliance/thing. I’ll meet you guys at the core.

Hackaday Prize Entry: A Numerically Controlled RepRap

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.

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Hackaday Prize Entry: Germanium Vision

The first digital cameras didn’t come out of a Kodak laboratory or from deep inside the R&D department of the CIA or National Reconnaissance Office. The digital camera first appeared in the pages of Popular Electronics in 1975, using a decapsulated DRAM module to create fuzzy grayscale images on an oscilloscope. For his Hackaday Prize project, [Alexander] is recreating this digital camera not with an easy to use decapsulated DRAM, but with individual germanium transistors.

Phototransistors are only normal transistors with a window to the semiconductor, and after finding an obscene number of old, Soviet metal can transistors, [Alex] had either a phototransistor or a terrible solar cell in a miniaturized package.

The ultimate goal of this project is to create a low resolution camera out of a matrix of these germanium transistors. [Alex] can already detect light with these transistors by watching a multimeter, and the final goal – generating an analog NTSC or PAL video signal – will “just” require a single circuit duplicated hundreds of times.

Digital cameras, even the earliest ones built out of DRAM chips, have relatively small sensors. A discrete image sensor, like the one [Alex] is building for his Hackaday Prize entry, demands a few very interesting engineering challenges. Obviously there must be some sort of lens for this image sensor, so if anyone has a large Fresnel sitting around, you might want to drop [Alex] a line.

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Hackaday Prize Entry: Glow In The Dark Plotting

We like big displays, whether they’re gigantic LED displays, CNC whiteboards, or a gigantic laser projectors. For his Hackaday Prize entry, [nilo] has come up with an easy way to create a huge graphical display. It might only work at night, but the Glowboard Plotter is still really cool.

[nilo]’s display is simply a very large glow in the dark sheet wrapped around two rollers, controlled by a stepper motor. By running the motor, the blank glow in the dark sheet slowly scrolls across.

To add some color to this display, [nilo] fixed 64 UV LEDs to one end of the display. By lighting these LEDs up at specific intervals and specific intensities, a ghostly green glowboard image appears across this display. Is it useful? About as much as any other gigantic LED matrix. Is it cool? About as much as any other gigantic LED matrix.

Right now, [nilo] is working on mk. 2 of the Glowboard Plotter, upgrading the control system and increasing the number of UV LEDs to 128. It may seem useless, but it’s still very cool and an excellent entry into the Anything Goes portion of this year’s Hackaday Prize.

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3D Printing Compressed Air Tanks

Using PVC pipe as a pressure vessel for compressed air can be a fun and enjoyable hobby. It’s safe, too: while there are are reports of PVC pipe being the cause of accidents, these accidents include a black powder potato gun[1], and welding too close to a PVC pipe containing compressed air[2]. Compressed air stored in a PVC pipe is never a proximal cause in any accident, and the OSHA’s Fatality and Catastrophe Investigation Summaries bear this out; there was no industrial or occupational accident recorded in these summaries where a pressure vessel made out of PVC was the cause of any injury or death[3].

Although PVC pipe can be a perfectly safe, effective, and cheap pressure vessel for hobby applications, it’s not always the best choice. A group of students in Renens, Switzerland are building autonomous robots for the Eurobot competition, and this year’s robot uses pneumatics. That means compressed air, and that means a pressure vessel. Since just about everything else on this robot is 3D printed, they asked the obvious question. Is it possible to 3D print a tank for compressed air?

The tank for this robot would only be used up to about 4 bar (400kPa), and after a few quick calculations, the team discovered the wall thickness – even in a pressure vessel with corners – would be pretty low. The first prototype, a 40mm cube with 20% infill and a hole drilled in the side, held 6.5 bar (650kPa) for an hour. This success didn’t last, though: he second prototype, a 65x40x80mm rectangular prism printed without as much infill, exploded at 5.5bar (550kPa).

The third time’s the charm, and with filleted ribs inside the tank, the third prototype was able to hold pressure up to 6.5 bar. Of course no 3D print is perfect, and the third prototype did leak, but a bit of acrylic spray paint applied to the outer surfaces held the air in.

While it’s not as fun, easy, cheap, rewarding, or safe as using PVC pipe as a pressure vessel, the team did manage to build a 3D printed pressure vessel with a custom shape. You can’t do that very easily with round pipe. And 3D printing opens up all manner of internal structure to experiment with. We’d like to see this developed even further!

Sources: [1], [2], [3]

Hackaday Meetup In The Middle Of Nowhere

Come one, come all, as the Hackaday community gathers at the childhood home of the worst president of the United States of America. Raise a glass, feast on roast pig, and don’t forget to Bring-A-Hack to show and tell. We’ll give away Hackaday Omnibus, stickers, and as a very special door prize a few people are going to walk away with a Raspberry Pi Zero.

The preamble about not-so-great heads of state is due to the venue. This gala is at the James Buchanan Pub & Restaurant in Mercersburg, PA on Sunday, June 5th, starting at 3PM. But that doesn’t really answer the question of why Mercersburg, does it? This is the location of one of the Hackaday World Create Day meetups. It caught my eye and since I live only 20 minutes away this is a great time for another get together.

Let’s fill the place with south central Pennsylvania’s greatest hardware hackers. There will be food, alcohol, and interesting people to talk to.