We’ll admit it. We like the results of resin 3D printing, but we don’t always care for the mess. We aren’t alone, and a common issue is to have drips of resin on your LCD screen — a potential disaster. You ought to have a screen protector, but yeah… you should back up hard drives, too. [Jessy] has the same problem and he has heard that you can easily clean cured resin from the screen using wood glue. Does it work? Check out the results of three glues in the video below.
We winced to see glue going on the screens. [Jessy] cured some resin on the screens deliberately for a test. He used Elmer’s wood glue, Gorilla wood glue, and Titebond II wood glue. While there is a bit of a price difference between the options, they are all fairly inexpensive.
It’s an unfortunate consequence of growing older, that no longer are you able to read the print on a SOT-23 package or solder a QFN without magnification. Your eyes inexorably start to fail, and to have any hope of continuing a set of reading glasses is required. We have this in common with [Niklas Roy], who noticed while shopping for cheap reading glasses that their lenses were of surprisingly good quality. The result of this observation was a stereoscope made from card and a few euros worth of eyewear.
In the tradition of [Niklas]’ work it has a high level of attention to detail, which manifests itself here in a parametric web-based template generator to produce a result tailored to your glasses. It’s a fairly straightforward trapezoid shape, with a compound lens made from two sets of glasses drilled and held back-to-back with zip ties.
It served as a project for a group of children, and of course because stereo cameras are a relative rarity he also investigated taking his own pictures by moving a smartphone for left and right eye perspectives. It seems the youngsters had a lot of fun.
These lenses hadn’t come up on our radar until now, but like many goodies in a dollar store they’re certainly something to take a look at. Maybe not as a stereoscope for everyone though, some of us can’t see what the fuss is about.
It seems obvious that if you dig or drill into the soil, at some point you will hit groundwater. Drill deep enough and you will reach an aquifer containing enormous amounts of fresh water. After this you can just pump water out of these wells and you will have fresh water aplenty. Or so was the thinking among many for the longest time. As enormous the fresh water reserves in the form of groundwater are – with most liquid fresh water being groundwater – we can literally empty them faster than that they’ll refill.
As the Dust Bowl disaster painfully showed in the 1930s and drought along with surface subsidence issues as in e.g. California’s Central Valley shows today is that we cannot simply use the soil and groundwater and expect no consequences. While the 19th century saw many fresh settlers to the West’s arid and semi-arid regions like California believe in the ‘Rain follows the plow‘ mysticism, the 20th century and these first few decades of the 21st century taught us that tilling the soil and drawing groundwater for irrigation does not change an arid climate into a lush one.
Perhaps ironically, even with increasing droughts, most human settlements use stormwater drainage and combined sewage systems to carry rainwater away, rather than letting the groundwater recharge naturally. Fortunately, more and more regions these days are seeing the necessity of managing groundwater.
Here at Hackaday, we focus mainly on engineering at the small end of the spectrum. Millimeter waves, nearly microscopic SMD components, nanoscale machines like MEMS accelerometers, and silicon chips with features that measure in the nanometer range. We’ve all become pretty good at wrapping our heads around problems at the wee end of the spectrum.
And while all that tiny stuff is great, there’s a whole, big world out there to explore, with big engineering to solve big problems. Think of things like dam spillways, lift bridges, and canal locks — big stuff that still has to move, and has to do it safely and efficiently. Those are problems that demand an entirely different way of thinking, and skills that not a lot of us have.
Andy Oliver works in the world of big, movable structures, designing control systems for them. He’ll drop by the Hack Chat to discuss the engineering that not only makes these structures work but also keeps them safe and reliable. If you’ve ever wondered how big things work, you won’t want to miss this one.
The other day, a medical office needed my insurance card. I asked them where to e-mail it and they acted like I had offered them human flesh as an appetizer. “We don’t have e-mail! You have to bring it to us in person!” They finally admitted that they could take a fax and I then had to go figure out how to get a free one page fax sent over the Internet. Keep in mind, that I live in the fourth largest city in the United States — firmly in the top 100 largest cities in the world. I’m not out in the wilderness dealing with a country doctor.
I understand HIPAA and other legal and regulatory concerns probably inhibit them from taking e-mail, but other doctors and health care providers have apparently figured it out. But it turns out that the more regulations are involved in something, the more behind-the-times it is likely to be.
We’re going to go out on a limb and predict that future history books will note that the decision to invade a sovereign nation straight after a worldwide pandemic wasn’t exactly the best timing. Turns out the global electronics shortage the pandemic helped to catalyze isn’t just affecting those of us with peaceful intentions, as the Russian war machine is having a few supply issues with the parts needed to build modern weapons and their associated control equipment.
As you might expect, many of these parts are electronic in nature, and in some cases they come from the same suppliers folks like us use daily. This article from POLITICO includes an embedded spreadsheet, broken down by urgency, complete with part numbers, manufacturers, and even the price Moscow expects to pay!
Chips from US-based firms such as Texas Instruments are particularly hard for the Kremlin to source.
So what parts are we talking about anyway? The cheapest chip on the top priority list is the Marvell ‘Alaska’ 88E1322 which is a dual Gigabit Ethernet PHY costing a mere $7.10 USD according to Moscow. The most expensive is the 10M04DCF256I7G, which is an Altera (now Intel) Max-10 series FPGA, at $1,101 USD (or 66,815 Rubles, for those keeping score).
But it’s not just chips that are troubling them, mil-spec D-sub connectors by Airborn are unobtainable, as are all classes of basic passive parts, resistors, diodes, discrete transistors. Capacitors are especially problematic (aren’t they always). A whole slew of Analog Devices chips, as well as many from Maxim, Micrel and others. Even tiny logic chips from Nexperia.
Of course, part of this is by design. Tightened sanctions prevent Russia from purchasing many of these parts directly, which is intended to make continued aggression as economically unpleasant as possible. But as the POLITICO article points out, it’s difficult to prevent some intermediaries from ‘helping out’ without the West knowing. After all, once a part hits the general market, it is next to impossible to guarantee where it will eventually get soldered down.
More specifically, the authors wanted to examine the use of 3D printing components to be used in a vacuum. Parts produced with filament-based printers tend to be porous, and as such, are not suitable for fittings or adapters which need to be pumped down to below one atmosphere. The paper goes on to explain that there are coatings that can be used to seal the printed parts, but that they can outgas at negative pressures.
The solution proposed by the team is exceptionally simple: after printing their desired parts in polypropylene on a Lulzbot Taz 6, they simply hit them with a standard consumer heat gun. With the temperature set at ~400 °C, it took a little under a minute for the surface of take on a glossy appearance — the result reminds us of an ABS print smoothed with acetone vapor.
As the part is heated, the surface texture visibly changes. The smoothed parts performed far better in vacuum testing.
In addition to the heat treatment, the team also experimented with increasing degrees of infill overlap in the slicer settings. The end result is that parts printed with a high overlap and then heat treated were able to reliably handle pressures as low as 0.4 mTorr. While the paper admits that manually cooking your printed parts with a heat gun isn’t exactly the ideal solution for producing vacuum-capable components, it’s certainly a promising start and deserves further study.
