Neil Movva: Adding (wearable) Haptic Feedback to Your Project

[Neil Movva] is not your average college student. Rather than studying for exams or preparing to defend a dissertation, he’s working on a project that will directly help the disabled. The project is Pathfinder, a wearable haptic navigation system for the blind. Pathfinder is an ambitious project, making it all the way to the semifinals of the 2015 Hackaday Prize. Haptics, the technology of providing feedback to a user through touch, lies at the core of Pathfinder. [Neil] was kind enough to present this talk about it at the Hackaday SuperConference.

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Hackaday Links: October 25, 2015

There are dozens of different 3D printable cases out there for the Raspberry Pi, but the BeagleBone Black, as useful as it is, doesn’t have as many options. The folks at 3D hubs thought they could solve this with a portable electronics lab for the BBB. It opens like a book, fits a half-size breadboard inside, and looks very cool.

The guy who 3D printed his lawnmower has a very, very large 3D printer. He now added a hammock to it, just so he could hang out during the very long prints.

There’s a box somewhere in your attic, basement, or garage filled with IDE cables. Wouldn’t they be useful for projects? Yep, only not all the wires work; some are grounds tied together, some are not wired straight through, and some are missing. [esot.eric] has the definitive guide for 80-wire IDE cables.

Like case mods? Here’s a golden apple, made out of walnut. Yes, there are better woods he could have used. It’s a wooden replica of a Mac 128 with a Mac Mini and LCD stuffed inside. Want a video? Here you go.

If you have a 3D printer, you’re probably familiar with PEEK. It’s the plastic used as a thermal break in non-all-metal hotends. Now it’s a filament. An extraordinarily expensive filament at €900 per kilogram. Printing temperature is 370°C, so you’ll need an all-metal hotend.

It’s the Kickstarter that just keeps going and going and going. That’s not a bad thing, though: there really isn’t much of a market for new Amiga 1200 cases. We’ve featured this project before, but the last time was unsuccessful. Now, with seven days left and just over $14k to go, it might make it this time.

Hackaday Links: October 18, 2015

We have our featured speakers lined up for the Hackaday Supercon, one of which is [Fran Blanche]. We’ve seen a lot of her work, from playing with pocket watches to not having the funding to build an Apollo Guidance Computer DSKY. In her spare time, she builds guitar pedals, and there’s a biopic of her in She Shreds magazine.

Halloween is coming, and that means dressing children up as pirates, fairies, characters from the latest Marvel and Disney movies, and electrolytic capacitors.

There’s a new movie on [Steve Jobs]. It’s called the Jobs S. It’s a major upgrade of the previous release, featuring a faster processor and more retinas. One more thing. Someone is trying to cash in on [Woz]’s work. This time it’s an auction for a complete Apple I that’s expected to go for $770,000 USD.

Hackaday community member [John McLear] is giving away the factory seconds of his original NFC ring (think jewelry). These still work but failed QA for small reasons and will be fun to hack around on. You pay shipping which starts at £60 for 50 rings. We’ve grabbed enough of them to include in the goody bags for the Hackaday Superconference. If you have an event coming up, getting everyone hacking on NFC is an interesting activity. If you don’t want 50+, [John] is also in the middle of a Kickstarter for an improved version.

Your 3D printed parts will rarely come out perfectly. There will always be some strings or scars from removing them from the bed. There’s a solution to these problems: use a hot air gun.

Everyone has a plumbus in their home, but how do they do it? First, they take the dinglebop, and smooth it out with a bunch of schleem. The schleem is then repurposed for later batches.

Macintosh Hard Drive Repair

The Macintosh II was a popular computer in the era before Apple dominated the coffee shop user market, but for those of us still using our Mac II’s you may find that your SCSI hard drive isn’t performing the way that it should. Since this computer is somewhat of a relic and information on them is scarce, [TheKhakinator] posted his own hard drive repair procedure for these classic computers.

The root of the problem is that the Quantum SCSI hard drives that came with these computers use a rubber-style bump stop for the head, which becomes “gloopy” after some time. These computers are in the range of 28 years old, so “some time” is relative. The fix involves removing the magnets in the hard drive, which in [TheKhakinator]’s case was difficult because of an uncooperative screw, and removing the rubber bump stops. In this video, they were replaced with PVC, but [TheKhakinator] is open to suggestions if anyone knows of a better material choice.

This video is very informative and, if you’ve never seen the inside of a hard drive, is a pretty good instructional video about the internals. If you own one of these machines and are having the same problems, hopefully you can get your System 6 computer up and running now! Once you do, be sure to head over to the retro page and let us know how you did!

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Drivers for 3D Printers and Why We Need Them

Manufacturers of 3D printers have a lot to do before they catch up with makers of the cheapest 2D, paper-based printers. If you’ve ever taken an inkjet apart, you’ll most likely find some sort of closed-loop control on at least one of the axes. The 2D printer will tell you when you’re out of ink, when a 3D printer will go merrily along, printing in air without filament. File formats? Everything is Gcode on a 3D printer, and there are dozens, if not hundreds of page description languages for 2D printers.

The solution to some of these problems are drivers – software for a 3D printer that slowly consumes the slicing of an object, printer settings, and placing an object on the bed. It’s coming, and the people who are responsible for making your 2D printer work with your computer are busy at work messing up the toolchain for your 3D printer.

The latest version of CUPS (C Unix Printing System) adds support for 3D printers. This addition is based on meetings, white papers, and discussions in the Printer Working Group (PWG). There has already been a lot of talk about what is wrong with the current state of 3D printer toolchains, what can be improved, and what should be completely ignored. Let’s take a look at what all of this has accomplished.

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44 Mac Pros Racked Up to Replace Each Rack of 64 Mac Minis

We were delighted at a seeing 96 MacBook Pros in a rack a couple of days ago which served as testing hardware. It’s pretty cool so see a similar exquisitely executed hack that is actually in use as a production server.  imgix is a startup that provides image resizing for major web platforms. This means they need some real image processing horsepower and recently finalized a design that installs 44 Mac Pro computers in each rack. This hardware was chosen because it’s more than capable of doing the heavy lifting when it comes to image processing. And it turns out to be a much better use of rack space than the 64 Mac Minis it replaces.

Racking Mac Pro for Production


Each of the 11 R2 panels like the one shown here holds 4 Mac Pro. Cooling was the first order of business, so each panel has a grate on the right side of it for cold-air intake. This is a sealed duct through which one side of each Pro is mounted. That allows the built-in exhaust fan of the computers to cool themselves, pulling in cold air and exhausting out the opposite side.

Port access to each is provided on the front of the panel as well. Connectors are mounted on the right side of the front plate which is out of frame in this image. Power and Ethernet run out the back of the rack.

The only downside of this method is that if one computer dies you need to pull the entire rack to replace it. This represents 9% of the total rack and so imgix designed the 44-node system to deal with that kind of processing loss without taking the entire rack down for service.

Why This Bests the Mac Mini

3 racks - Linux. Mac Min, Mac Pro
3 racks – Linux. Mac Min, Mac Pro

Here you can see the three different racks that the company is using. On the left is common server equipment running Linux. In the middle is the R1 design which uses 64 Mac Minis for graphic-intensive tasks. To the right is the new R2 rack which replace the R1 design.

Obviously each Mac Pro is more powerful than a Mac Mini, but I reached out to imgix to ask about what prompt them to move away from the R1 design that hosts eight rack panes each with eight Mac Minis. [Simon Kuhn], the Director of Production, makes the point that the original rack design is a good one, but in the end there’s just too little computing power in the space of one rack to make sense.

Although physically there is room for at least twice as many Mac Mini units — by mounting them two-deep in each space — this would have caused several problems. First up is heat. Keeping the second position of computers within safe operating temperatures would have been challenging, if not impossible. The second is automated power control. The R1 racks used two sets of 48 controllable outlets to power computers and cooling fans. This is important as the outlets allow them to power cycle mis-behaving units remotely. And finally, more units means more Ethernet connections to deal with.

We having a great time looking that custom server rack setups. If you have one of your own, or a favorite which someone else built, please let us know!

[Thanks to drw72 for mentioning R2 in a comment]

29 Year Old Apple Computer Finally Gets An OS Update

The Apple IIGS is the 16 bit upgrade to the popular 8 bit Apple II computer line, and with its massive boost in graphics, an Ensoniq sound system, and backwards compatibility with the 8 bit machines makes this box desirable to many retro enthusiast. The last OS update, 6.0.1, was released over 22 years ago. While it worked well for the early 90s, it was by no means perfect.

Last Sunday, a post popped up on, announcing Apple IIgs System 6.0.2. Updates include a driver for the unreleased Apple II Ethernet card,  fixes various bugs in the file system translation system, various bugfixes to existing system programs,  fast drawing and animation tools, and of course an update to the finder to show the new revision number.

With a hope for even more bug fixes in a possible 6.0.3 revision its good to see people still giving the old Apple II line some love, as the old Apples don’t have as large of a following as their Atari and Commodore brethren.