Scan Your Film The 3D Printed Way

February 19, 2018 by Jenny List 7 Comments

Everyone has a box or two at home somewhere full of family photographs and slides from decades past. That holiday with Uncle Joe in Florida perhaps, or an unwelcome reminder of 1987’s Christmas jumper. It’s fair to say that some memories deserve to be left to gather dust, but what about the others in a world of digital images?

You could of course buy a film scanner to digitize Uncle Joe on the beach, but aside from the dubious quality of so many of them where’s the fun in that? Instead, how about 3D printing one? That’s what [Alexander Gee] did, in the form of an adapter to fit the lens mount of his Sony camera that contains both a 50mm enlarger lens and a mount for the slide. It’s a simple enough print, but he’s made enough parts parametric for users to be able to adjust it to their own camera’s mount.

Sometimes builds do not have to be complex, push boundaries, or contain more computing power than took us to the Moon. This one is simple and well-executed, and for anyone prepared to experiment could deliver results with a variety of cameras and lenses. Of course, you have to have some film to scan before you can use it, so perhaps you’d like to try a bit of home developing.

Help Keep The Bombe At Bletchley

February 17, 2018 by Jenny List 36 Comments

Fans of vintage codebreaking machinery might be interested to hear that the only working reconstruction of a Turing-Welchman Bombe is likely to soon be on the move. The electromechanical device, a replica of those used on the Second World War Enigma codes, is housed at Bletchley Park, the former codebreaking center established before the outbreak of war to house British and Polish codebreakers.

Bletchley Park itself is now a tourist attraction. The news is that a display reorganization has caused the Turing Welchman Bombe Rebuild Trust that owns the Bombe to approach the neighboring National Museum Of Computing with a view to housing it alongside their reconstruction of the Colossus electronic computer. The Colossus was famously used on the Lorenz cipher. This is an exciting development for the museum, but as an organization reliant on donations they face the task of finding the resources to create a new gallery for the arrival. To that end, they have launched a crowdfunding campaign with a target of £50000 ($69358.50), and they need your donations to it for the project to succeed. They have raised over £4500 in the few days it has already been open and there is most of a month still to go, so we hope they achieve their goal.

The Bletchley Park site is now surrounded by the post-war new town of Milton Keynes, and is easy enough to get to should you find yourself in the UK. We visited The National Museum Of Computing a couple of years ago and spent a very happy day touring its extensive and fascinating collection. If you want to read more about the Bombe you might like to read our review, and also our impression of Colossus.

As part of their campaign, the museum has produced a promotional video, which we have placed after the break.

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Repairs You Can Print: A Turn Signal Switch For A Chevy Corvair

February 17, 2018 by Jenny List 14 Comments

Running a classic car is often an easier prospect than a more recent model, as the mechanical parts have a tendency towards commonality between models, simplicity, and maintenance using basic tools. However assuming some level of parts availability for your model it is not usually the running gear that causes headaches. Instead, it is the smaller and less durable parts, the little plastic pieces that formed vital components but have not been manufactured for decades. These are the parts for which the advent of accessible 3D printing has been a revelation, suddenly the owner of a wreck need only to have basic CAD skills to deliver the goods.

A Chevy Corvair (not [Ken]'s one). Greg Gjerdingen [CC BY 2.0]. — A Chevy Corvair like [Ken’s]. Greg Gjerdingen [CC BY 2.0].

[Ken] has a ’63 Chevy Corvair, an attractively-styled motor notable for its rear-engined layout and air-cooled engine. And it seems his car is plagued by the same issue as all other early models, a failure of its turn signal mechanism. The version fitted to later cars is a vastly superior replacement, but required some modification to fit his ’63 model. Even after modifcation, the updated part had a plastic component that was too long for his steering wheel. Would he grind down the later part to fit, or go with a later wheel? No, he turned to Google Sketchup, and 3D printed a replacement of the correct size. He does admit that it’s not perfect as the signals cancel at a slightly different point from where they should, but since he’s been using it for four years it appears to have done the job.

We wish [Ken] every success with his Corvair, and indeed can’t help envying him a little for owning it. Some of us have been known to dabble in older metal, too.

This is an entry in Hackaday’s

Repairs You Can Print contest

The twenty best projects will receive $100 in Tindie credit, and for the best projects by a Student or Organization, we’ve got two brand-new Prusa i3 MK3 printers. With a printer like that, you’ll be breaking stuff around the house just to have an excuse to make replacement parts.

Retrotechtacular: AM Radios, Core Memory, And Color TV, What Was Hot In Chips In ’73

February 16, 2018 by Jenny List 23 Comments

As part of writing tech stories such as those we feature here at Hackaday, there is a huge amount of research to be done. We trawl through pages and pages of obscure blogs, videos, and data sheets. Sometimes we turn up resources interesting enough that we file them away, convinced that they contain the nucleus of another story at some point in the future.

Today’s topic of entertainment is just such a resource, courtesy of the Internet Archive. It’s not a video as we’d often provide you in a Retrotechtacular piece, instead it’s the February 1973 edition of the Fairchild Semiconductor Linear Integrated Circuits Catalog. Books like this one that could be had from company sales representatives were highly prized in the days before universal Internet access to data sheets, and the ink-on-paper datasheets within it provide a fascinating snapshot of the integrated electronics industry as it was 45 years ago.

The first obvious difference between then and now is one of scale, this is a single volume containing Fairchild’s entire range. At 548 pages it wouldn’t have been a slim volume by any means, but given that Fairchild were at the time one of the big players in the field it is unimaginable that the entire range of a 2018 equivalent manufacturer could be contained in the same way. Given that the integrated circuit was at the time an invention barely 15 years old, we are looking at an industry still in relative infancy.

The catalog has a series of sections with familiar headings: Operational amplifiers, comparators, voltage regulators, computer/interface, consumer, and transistor/diode arrays with analog switches. Any modern catalog will have similar headings, and there are even a few devices you will find have survived the decades. The μA741 op-amp (page 64) from its original manufacturer has not yet become a commodity product here, and it sits alongside familiar devices such as the μA7800 series (page 201) or μA723 (page 194) regulators.

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The UA723 As A Switch Mode Regulator

February 15, 2018 by Jenny List 37 Comments

If you are an electronic engineer or received an education in electronics that went beyond the very basics, there is a good chance that you will be familiar with the Fairchild μA723. This chip designed by the legendary Bob Widlar and released in 1967 is a kit-of-parts for building all sorts of voltage regulators. Aside from being a very useful device, it may owe some of its long life to appearing as a teaching example in Paul Horowitz and Winfield Hill’s seminal text, The Art Of Electronics. It’s a favourite chip of mine, and I have written about it extensively both on these pages and elsewhere.

The Fairchild switching regulator circuit. From the μA723 data sheet in their 1973 linear IC databook, page 194 onwards.

For all my experimenting with a μA723 over the decades there is one intriguing circuit on its data sheet that I have never had the opportunity to build. Figure 9 on the original Fairchild data sheet is a switching regulator, a buck converter using a pair of PNP transistors along with the diode and inductor you would expect. Its performance will almost certainly be eclipsed by a multitude of more recent dedicated converter chips, but it remains the one μA723 circuit I have never built. Clearly something must be done to rectify this situation.

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Returning A Lost Sheep To The NASA Fold

February 13, 2018 by Jenny List 48 Comments

About three weeks ago, we reported that a satellite enthusiast in Canada found an unexpected signal among his listening data. It was a satellite, and upon investigation it turned out to be NASA’s IMAGE satellite, presumed dead since a power failure in 2005 interrupted its mission to survey the Earth’s magnetosphere.

This story is old news then, they’ve found IMAGE, now move on. And indeed the initial excitement is past, and you might expect that to be it from the news cycle perspective. But this isn’t the Daily Mail, it’s Hackaday. And because we are interested in the details of stories like these it’s a fascinating read to take a look at NASA’s detailed timeline of the satellite’s discovery and subsequent recovery.

In it we read about the detective work that went into not simply identifying the probable source of the signals, but verifying that it was indeed IMAGE. Then we follow the various NASA personnel as they track the craft and receive telemetry from it. It seems they have a fully functional spacecraft with a fully charged battery reporting for duty, the lost sheep has well and truly returned to the fold!

At the time of writing they are preparing to issue commands to the craft, so with luck by the time you read this they will have resumed full control of it and there will be fresh exciting installments of the saga. Meanwhile you can read our report of the discovery here, and read about a previous satellite brought back from the dead.

Picture of IMAGE satellite: NASA public domain.

Need Strength? It’s Modified Wood You Want!

February 12, 2018 by Jenny List 29 Comments

Wood is surely one of the most versatile materials available. It can be found in a huge variety of colours and physical properties depending on the variety of the tree that grew it, and it has been fashioned into all conceivable devices, products, and structures over millenia. It’s not without shortcomings though, and one of the most obvious is that it can’t match the strength of some other materials. To carry large forces with a piece of wood that piece has to be made much larger than a corresponding piece of steel, something which is not a problem in a roof truss, but significantly difficult in a car body.

There have been a variety of attempts to strengthen the structure of wood in the past, and the latest has recently been published as a Nature paper. In it is described a process of first treating natural wood in a chemical bath to remove lignin and leave only the cellulose structure, followed by sustained compression at high temperature. This causes the cellulose fibres to interlock, and leaves a much denser wooden board with an equivalent strength that is described as near that of steel. They’ve posted a video which we’ve placed below the break, showing some ballistic tests on their material.

All new materials are of interest, but assuming that this one can be commercialised it makes for a particularly exciting set of possibilities. Wooden motor vehicles for example, new techniques for wooden aircraft or boats, or as an alternative in some applications where carbon fibre might currently find an application.

We’ve looked at a very similar process in the past for producing transparent wood. The good news for Hackaday readers that takes this from esoteric scientific paper to fascinating possibility though is that it can be done at home. Can any of you replicate the pressing step to take it to the next level?

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