Author: Jenny List

3314 Articles

Review: Lidl Parkside Micrometer

August 29, 2022 by 50 Comments

A couple of years ago we published a look at precision measurement tools, in particular vernier calipers and micrometer screw gauges. It featured a look at how they work and how they’re used, and a comparison of good and bad quality instruments. When comparing micrometers we had three of them, a Mitutoyo and a Moore & Wright representing decent quality, and an £8 ($9.41) Daniu from Banggood from the cheaper end of the market. As you might expect, the Daniu was laughably bad, with noticeable play in its thread and jaws that were not parallel to the extent you could see light between them. You might consider it case closed for cheap micrometers then, were it not that while on my summer travels through the Benelux countries I spied a Parkside micrometer in a Lidl supermarket for €8.99 ($8.92). I had to buy it and investigate.

Some Measuring Devices With Your Groceries?

The Parkside micrometer in its boxLidl is a German supermarket chain that can be found all over Europe, and like their arch-competitor Aldi they feature the “Middle of Lidl” aisles full of all sorts of useful stuff that changes on a regular basis. Among this is a comprehensive range of tools under the Parkside brand, which is basically on par with the good stuff from Harbor Freight, and are in fact quite good for the price. Thus even though it’s about the same price as the Daniu I had higher expectations for the Parkside micrometer.

The micrometer is packaged in the usual plastic case in a small cardboard box, and comes with a large paper instruction sheet and a small spanner for zero adjustment. Taking it out of the case, it follows exactly as you’d expect from a micrometer with a solid drop-forged frame and an aluminium barrel on the micrometer head. It can measure up to 25 mm at a resolution of 0.01 mm, exactly like the others I tested in 2020. So my nine dollars or so has got me a micrometer, but is it any good? How do you evaluate a micrometer screw gauge? I re-borrowed the two comparison instruments from 2020, and set out to find out.

The Tiniest Sliver Of Light Gives It Away

The mirror finish on the Mitutoyo jaw face reflecting the "H" of the Hackaday website.
The mirror finish on the Mitutoyo jaw face reflecting the “H” of the Hackaday website.

It’s worth saying that the jaw faces are polished, but not to a mirror finish as those on the Mitutoyo and neither do they appear to have been hardened. In the first instance, comparing with the Daniu I closed the jaws against the force of the ratchet, and held it up against the light to spot any imperfections in the way they meet. Against the blue sky through my window I couldn’t see any, but a friend did the same thing against the more intense point source of an electric light and indeed there was the tiniest discernable sliver of light. Not the obvious wedge of light I caught with the Daniu back in 2020 and less than the visible sliver of light when it is measuring a human hair, but definitely enough to knock a few hundredths of a milimetre off my trust in its accuracy.

The next step in the evaluation involves opening the  jaws about half way, and feeling for any play in the thread. None discernable, at least one win over the Daniu which had the barrel flapping around with significant play. Then a zero test, after adjusting the zero position with the spanner a few repeated closings with the ratchet, to check that it always returns to the same zero point. In this case as with all micrometers it’s possible to overshoot the zero and damage the thread if you apply too much force, but just on the ratchet it would land in the same place.  A pass on a couple of tests then, so while it’s not the worst micrometer ever it’s obvious that the low price brings at least one compromise.

A Tiny Discrepancy In Measurement

Opening up the three micrometers from the 2020 piece again it’s immediately obvious in the silky feel of the thread and the lack of wobble in the ratchet just where the money goes in an expensive micrometer, and just how comedically bad the Daniu was by comparison. But it’s the Parkside in our sights today, so it’s time to make a few comparitive measurements between it and the Mitutoyo. First up were the old standbys of a piece of paper and a human hair in which the Parkside returned the same as the Mitutoyo, and then the machined shaft of the Moore & Wright which returned a difference of 0.01 mm.

Parkside Mitutoyo
Sheet of paper 0.12 mm 0.12 mm
Human hair 0.05 mm 0.05 mm
Moore & Wright shaft 6.79 mm 6.80 mm

The discrepancy in this table when measuring the shaft may be small, but it harks back to that sliver of light from imperfectly aligned jaws. As expected if the shaft meets the jaws at anything but the highest point of the jaw it will return a slightly smaller reading, thus it immediately has an error on everything it returns. Discussing it with friends there was raised the intriguing possibility of lapping the faces by drawing a sheet of exceptionally fine abrasive through the closed jaws, however I have my doubts as to whether this would do anything but make the gap worse.

What I can say about the Parkside micrometer screw gauge is that it appears reasonably well-built, but I can’t present it as the equal of the more expensive instruments when its faces are anything but parallel. I would say therefore that it would be good for basic measurements when machining or in CAD work where an error of 0.01 mm or 0.02 mm wouldn’t matter too much, but perhaps I wouldn’t quite trust it when working with extremely fine tolerances. Still, it’s not the worst among cheap micrometers and it’s on sale for a very reasonable price even if it’s not in the same precision instrument league as the Mitutoyo. If you don’t have a micrometer screw gauge yet then you could do a lot worse at this end of the market.

A Pi Camera To Be Proud Of

August 28, 2022 by 16 Comments

The Raspberry Pi HQ camera has appeared in a variety of builds since its introduction back in 2020, and has brought with it many opportunities for photographic projects to compete with the professionals. The latest we’ve been sent is from [Kevin McAleer], who has taken the camera with a full-size Pi and clothed it in a case very similar to the crop of mirror-less compact cameras.

Inside the box is a Waveshare touchscreen that fits on the GPIO header, and a NanoWave 5000 mAH USB battery pack. The camera module fits on the front of the unit, with the C-mount ready to take a lens. Software is still a work in progress and is promised to be a Python script controlling the various camera programs. There are enough Pi camera projects for software to be a matter of choice and taste.

We like the form factor and we like the use of the very compact NanoWave battery, so we think this is a design with some possibilities. Perhaps a cover over the Pi ports might be of use though for general robustness in the face of everyday photography. The question remains though, whether it can come close to the performance of even a budget mirror-less compact camera, and we’re guessing that will depend as much on the operator skill, lens quality, and software capabilities as it does on the Pi HQ module. We look forward to seeing what comes of this project, but meanwhile you can see a video with all the details below the break.

Continue reading “A Pi Camera To Be Proud Of” →

A Raspberry Pi Handheld Computer You Might Want To Use

August 27, 2022 by 49 Comments

Amid the many wonderful form factors being explored by the makers of cyberdecks, there’s one that’s emerged which harks back to an earlier generation of portable computers: the handheld pad with a keyboard. These units are typically around the size of a hardback book, with the upper half being a screen and the lower a keyboard. The latest to come our way is from [Richard Sutherland], and it’s a very tidy pad computer indeed.

Inside the well-designed layered 3D printed case is the frequently-chosen Raspberry Pi 4, along with a PiSugar power supply board and 5,000 mAH battery and a 4.3″ touchscreen display. The keyboard has seen a lot of care and attention, featuring high-quality tactile switches that follow the Miryoku keyboard layout. He says it’s a thumb-typing keyboard, but anyone looking for more can either adapt the design to their liking or simply plug in an external board when faster typing is needed.

We like the pad computer trend as it offers useful computing power in a far more convenient format than a laptop, and we think this is a particularly nice one. It would be nice to see where people take this design, and who knows, we might give one a try for writing some Hackaday articles. If you’d like to see more pad computer goodness, we recently showed you one built in the shell of a classic Amstrad.

You Paid For This Paper. Now You Can Read It Without Paying Again

August 26, 2022 by 44 Comments

There is probably very little among the topics covered here at Hackaday that doesn’t have its roots somewhere in scientific research. Semiconductor devices for example didn’t simply pop into being in Bell Labs or Texas Instruments, the scientists and engineers who created them did so standing on the shoulders of legions of earlier researchers who discovered the precursor steps that made them possible. As many readers will know, scientific research for its own sake is expensive, so much so that much of it is funded by governments, from your taxes. The research papers with the findings are then hidden from public view behind paywalls by the publishers who distribute them, an injustice which should soon be over for Americans, thanks to a White House memorandum paving the way for federally funded research to be freely available to the public at no cost by no later than 2025.

The academic publishing business originates in the days when paper was king, and it has several tiers. Officially an academic journal is usually the product of a professional body in its field, but it is normal for the publishing itself to be contracted out to a specialist academic publishing company. They accept submissions of papers, edit them, and arrange peer reviewers, before publishing the journals. Originally this was a paper process, but while journals are still printed it’s the Internet through which they are now read. The publishers pay nothing to the researcher for their paper and often only a nominal sum to the reviewers for their input, but charge a hefty subscription for access to the content. As you might imagine it’s an extremely lucrative business, so as this Hackaday scribe saw when she worked in that industry, the publishers and the learned bodies are in no hurry to kill their golden goose.

This move to open access may make few immediate waves outside the world of scientific publishing, but it affirms the principle that taxpayers should be able to see the fruits of their spending. As such it will be of benefit to less-well-off researchers and institutions worldwide. Rest in peace Aaron Swartz, if only you could have seen this day!

White House pic: Matt H. Wade, CC BY-SA 3.0.

Buy The Right To Build A Nakagin Tower Anywhere

August 25, 2022 by 41 Comments

We’re guessing that among Hackaday’s readership are plenty of futurists, and while the past might be the wrong direction in which to look when considering futurism, we wouldn’t blame any of them for hankering for the days when futurism was mainstream.

Perhaps one of the most globally iconic buildings of that era could have been found in Tokyo, in the form of the Nakagin Capsule Tower, Kisho Kurokawa’s 1972 Metabolist apartment block. This pioneering structure, in which individual apartments were conceived as plug-in units that could be moved or changed at will, never achieved its potential and was dismantled, looking more post-apocalyptic than futuristic in early 2022, but it could live on in both digital form and reconstructed elsewhere as the rights to its design are being auctioned.

Unfortunately there appears to be some NFT mumbo-jumbo associated with the sale, but what’s up for auction is a complete CAD model along with the rights to build either real or virtual copies of the building. It’s unlikely that any Hackaday readers will pony up for their own Metabolist skyscraper, but the interest lies not only in the love of a future that never quite happened, but in the engineering behind the structure. Where this is being written as in many other places there is simultaneously a chronic housing shortage and a housing system wedded to the outdated building techniques of a previous century, so the thought of updated equivalents of the Nakagin Tower offering the chance of modular interchangeable housing in an era perhaps more suited to it than the 1970s is an intriguing one. Now that we’re living in the future, perhaps it’s time to give futurism another chance.

Regular readers will have spotted this isn’t the first time we’ve brought you a taste of futuristic living.

Header: Svetlov Artem, CC0.

Telephoto Lens Without The Fiscal Pain

August 24, 2022 by 20 Comments

If you’re in the market for a telephoto lens, the available range of optics for your camera is limited only by the size of your bank account. So when [Pixels and Prisms] promises a telephoto for $13 USD it has to be worth a second look, right? Where’s the catch.

The lens has a 3D printed shell containing the optics, with associated focusing and aperture, and has a mount designed for Canon cameras to give a result with 163 mm focal length and f/2.5 . When a Canon lens costs many times more it’s evident that there is some compromise involved, and it comes in the lens system being very simple and comprised of off-the-shelf surplus lenses without the great effort put in by the manufacturer to correct distortion. The result is nonetheless a very creditable lens even if not the first choice for a paparazzo in pursuit of an errant politician.

The real interest for us in this open source project comes in it being something of an experimenter’s test bed for lenses. There’s no need to use the combination shown and the design can be readily adapted for other lenses, so spinning one’s own lens system becomes a real possibility. Plus it’s achieved the all-too-easy task of engaging a Hackaday writer’s time browsing the stock of the Surplus Shed.

We’ve featured a lot of lens projects over the years, but they more often take an existing camera lens as a starting point.

An ASCII Terminal Like It’s 1974

August 21, 2022 by 10 Comments

It’s quite probable that any of you who have built a keyboard will have done so using a matrix of keys connected to a microcontroller, or if you are old-school, a microprocessor. A CPU can scan the keyboard matrix with ease, and pass whatever is typed either to whatever software it is running, or to a host computer. There was a time however when available CPUs were not considered powerful enough to do all this and also perform a useful task, so a keyboard would have its own decoder chip that would output ASCII over a parallel interface. It’s an era [John Calhoun] harks back to with Adam74, a little ASCII terminal which takes its input from that 7-bit parallel port.

In the place of a forest of TTL chips which might have graced the originals, within that attractive curved laser cut acrylic case is an LCD display and a Teensy microcontroller board. There’s a level shifter for the classic 5 volt logic, and of course a small buzzer for the essential BEL character. In these days when a parallel interface is relatively rare, he describes the rediscovery of alternate earth lines in a ribbon cable to minimize cross-talk. Should you wish to try your own, everything can be found on GitHub.

All in all it’s a fun way to rediscover an old idea.