Hackaday Links: July 24, 2016

July 24, 2016 by Brian Benchoff 9 Comments

Right now HOPE is dying down, and most of the Hackaday crew will be filtering out of NYC. It was a great weekend. The first weekend in August will be even better. We’re going to DEF CON, we’ll have people at VCF West, and a contingent at EMF Camp. If you’re going to EMF Camp, drop a line here. There will be Hackaday peeps wandering around a field in England, so if you see someone flying the Hackaday or Tindie flag, stop and say hi.

Raspberry Pi’s stuffed into things? Not all of them are terrible. The Apple Extended keyboard is possibly the best keyboard Apple ever produced. It’s mechanical (Alps), the layout is almost completely modern, and they’re actually cheap for something that compares well to a Model M. There’s also enough space inside the plastic to fit a Pi and still have enough room left over for holes for the Ethernet and USB ports. [ezrahilyer] plopped a Pi in this old keyboard, and the results look great. Thanks [Burkistana] for sending this one in.

We’ve been chronicling [Arsenijs] Raspberry Pi project for months now, but this is big news. The Raspberry Pi project has cracked 10k views on Hackaday.io, and is well on track to be the most popular project of all time, on any platform. Congrats, [Arsenijs]; it couldn’t happen to a better project.

A few months ago, [Sébastien] released SLAcer.js, a slicer for resin printers that works in the browser. You can’t test a slicer without a printer, so for the last few months, [Sébastien] has been building his own resin printer. He’s looking for beta testers. If you have experience with resin printers, this could be a very cool (and very cheap) build.

Anyone going to DEF CON? For reasons unknown to me, I’m arriving in Vegas at nine in the morning on Wednesday. This means I have a day to kill in Vegas. I was thinking about a Hackaday meetup at the grave of James T. Kirk on Veridian III. It’s about an hour north of Vegas in the Valley of Fire State Park. Yes, driving out to the middle of the desert in August is a great idea. If anyone likes this idea, leave a note in the comments and I’ll organize something.

Retrotechtacular: The Modern Telephone

July 23, 2016 by Jenny List 22 Comments

We take recorded telephone messages for granted in these days of smartphones and VOIP. Our voicemail lives on an anonymous server in a data centre in the cloud somewhere, in a flash memory chip on our DECT base station, or if we’re of a retro persuasion, on a micro-cassette. Wherever we go, we now know our calls will not go unanswered.

Today’s subject takes us back to a time when automatically recording a phone call was the last word in high technology, with a British Pathé newsreel piece from 1959 entitled “Modern Telephone”. Its subject is the Ansafone J10, one of the first telephone answering machines available on the British market. After featuring a fantastic home-made Meccano answering machine with turntable recording created by a doctor, it takes us to the Ansafone factory where the twin tape mechanisms of the commercial model are assembled and tested. Finally we get to see it in use on the desk of a bona fide Captain of Industry, probably about the only sort of person who could afford an Ansafone in 1959.

Part of the film’s charm comes not from the technology but from the glimpse it gives us of 1950s Britain sanitised for the newsreel. The clipped tones, leather armchairs and bookshelves, the coal fire and the engineer in a three-piece suit. The past is a foreign country; they do things differently there.

Take a look at the film below after the break, and never take your recorded calls for granted again.

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Fail Of The Week: Ferrofluid

July 22, 2016 by Elliot Williams 16 Comments

It’s more of a half-fail than a full fail, but [Basti] is accustomed to getting things right (eventually) so it sticks in his craw that he wasn’t able to fully realize his ferrofluid dreams (German, translated here). Anyway, fail or demi-fail, the project is certainly a lesson in the reality of ferrofluid.

We’ve all seen amazing things done with ferrofluid and magnets. How hard can it be to make an interactive ferrofluid wedding present for his sister? Where ferrofluid spikes climb up a beautifully cut steel heart in a jar? (Answer: very hard.)

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By Christian Taube - Own work, CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=1503038

Tools Of The Trade – Through Hole Assembly

July 22, 2016 by Bob Baddeley 31 Comments

In our last installment of Tools of the Trade, we had just finished doing the inspection of the surface mount part of the PCB. Next in the process is the through hole components. Depending on the PCB, the order may change slightly, but generally it makes more sense to get all the SMT work done before moving to the through hole work.

Through hole used to be the standard, but as the need for size reduction and automation increased, SMT gained favor. However, there are still a lot of reasons to use through hole components, so they aren’t going away entirely (at least not any time soon). One of the biggest advantages of THT is mechanical strength, which makes it better suited for connectors than SMT. If you’ve ever popped a microusb connector off a PCB by breathing on it heavily, you’ll understand. So, how do we most efficiently get through hole components on a PCB, and how do the big boys do it?

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Books You Should Read: Instruments Of Amplification

July 21, 2016 by Steven Dufresne 33 Comments

Psst… Wanna make a canning jar diode? A tennis ball triode? How about a semiconductor transistor? Or do you just enjoy sitting back and following along an interesting narrative of something being made, while picking up a wealth of background, tips and sparking all sorts of ideas? In my case I wanted to make a cuprous oxide semiconductor diode and that lead me to H.P. Friedrichs’ wonderful book Instruments of Amplification. It includes such a huge collection of amplifier knowledge and is a delight to read thanks to a narrative style and frequent hands-on experiments.

My well worn copy of Instruments of Amplifications

DIY point-contact semiconductor transistor

Friedrichs first authored another very popular book, The Voice of the Crystal, about making crystal radios, and wanted to write a second one. For those not familiar with crystal radios, they’re fun to make radios that are powered solely by the incoming radio waves; there are no batteries. But that also means the volume is low.

Readers of that book suggested a good follow-up would be one about amplifier circuits, to amplify the crystal radio’s volume. However, there were already an abundance of such books. Friedrichs realized the best follow-up would be one on how to make the amplifying components from scratch, the “instruments of amplification”. It would be unique and in the made-from-scratch spirit of crystal radios. The book, Instruments of Amplification was born.

The Experiments

Microphonic relays, via H.P. Friedrichs Homepage

The book includes just the right amount of a history, giving background on what an amplifier is and how they first came in the electrical world. Telegraph operators wanted to send signals over greater and greater distances and the solution was to use the mix of electronics and mechanics found in the telegraph relay. This is the springboard for his first project and narrative: the microphonic relay.

The microphonic relay example shown on the right places a speaker facing a microphone; the speaker is the input with the microphone amplifying the output. He uses a carbon microphone salvaged from an old telephone headset, housing everything in an enclosure of copper pipe caps, steel bar stock, nuts and bolts mounted on an elegant looking wood base. All the projects are made with simple parts, with care, and they end up looking great.

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Retrotechtacular: The Incredibly Difficult Task Of Copying A Document

July 20, 2016 by Al Williams 57 Comments

It seems hard to imagine, but in the early part of the 20th century, there weren’t a lot of great options for creating copies of documents. The most common method was to use carbon paper to create multiple copies at once from a typewriter or a line printer. All that changed with a company called Haloid. Never heard of them? They later became the Xerox company.

The underlying technology dates back to 1938 (invented by a physicist who was also a lawyer). In 1944, they produced a practical copier and shortly thereafter sold the rights to Haloid. The Haloid company originally made photographic copy machines that used wet chemistry.

In 1959, the Xerox 914 (so called because it could copy a 9″ x 14″ document) came on the scene (that’s it, below). The 650 pound copier could make seven copies per minute and came with a fire extinguisher because it had a tendency to burst into flames. If you didn’t want to spend the $27,500 price tag, you could rent for only $25/month (keep in mind that in 1959, $25 would buy about 25 pounds of T-bone steaks). You can see a commercial for the 914 in the video below.

In the commercial, you’ll see them make a big deal out of the fact that the print was dry. That’s because a lot of previous machines used actual photographic processes with wet chemistry. Obviously, that also took special paper.

Even Further Back

If the copier didn’t exist until recently, how did people make copies before? Turns out there were lots of ways to make copies of varying degrees of bad quality or extreme trouble. In some sense, the best copies were made by scribes just writing down a second copy of things. There were a variety of machines that would capture what you wrote and make a copy by mechanical or other means. A polygraph (not the lie detecting kind) allowed Thomas Jefferson to write letters and make a copy. The machine moved a pen to match the movements of the author’s pen, thus making a near perfect copy. With a few adjustments, this became the pantograph which not only does the same job, but also can shrink or enlarge the copy. Carbon paper was widely used to make multiple copies of handwritten and typewritten documents.

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3D Printering: G-Code Post Processing With Perl

July 20, 2016 by Moritz Walter 31 Comments

Most of our beloved tools, such as Slic3r, Cura or KISSlicer, offer scripting interfaces that help a great deal if your existing 3D printing toolchain has yet to learn how to produce decent results with a five headed thermoplastic spitting hydra. Using scripts, it’s possible to tweak the little bits it takes to get great results, inserting wipe or prime towers and purge moves on the fly, and if your setup requires it, also control additional servos and solenoids for the flamethrowers.

This article gives you a short introduction in how to post-process G-code using Perl and Slic3r. Perl Ninja skills are not required. Slic3r plays well with pretty much any scripting language that produces executables, so if you’re reluctant to use Perl, you’ll probably be able to replicate most of the steps in your favorite language.

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