With A Little Heat, Printed Parts Handle Vacuum Duty

September 13, 2022 by Tom Nardi 40 Comments

We don’t have to tell the average Hackaday reader that desktop 3D printing has been transformative for our community, but what might not be as obvious is the impact the technology has had on the scientific community. As explained in Thermal Post-Processing of 3D Printed Polypropylene Parts for
Vacuum Systems by [Pierce Mayville], [Aliaksei Petsiuk], and [Joshua Pearce], the use of printed plastic parts, especially when based on open source designs, can lead to huge cost reductions in the production of scientific hardware.

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.

A black PCB with an ESP32 and an SBM-20 geiger counter

Flexible Radiation Monitoring System Speaks LoRa And WiFi

September 10, 2022 by Robin Kearey 12 Comments

Radioactivity has always been a fascinating phenomenon for anyone interested in physics, and as a result we’ve featured many radioactivity-related projects on these pages over the years. More recently however, fears of nuclear disaster have prompted many hackers to look into environmental radiation monitoring. [Malte] was one of those looking to upgrade the radiation monitor on his weather station, but found the options for wireless geiger counters a bit limited.

So he decided to build himself his own Wifi and LoRa compatible environmental radiation monitor. Like most such projects it’s based on the ubiquitous Soviet-made SBM-20 GM tube, although the design also supports the Chinese J305βγ model. In either case, the tube’s operating voltage is generated by a discrete-transistor based oscillator which boosts the board’s 5 V supply to around 400 V with the help of an inductor and a voltage multiplier.

Graphs showing temperature, humidity and radiation levels — Data can be visualized in graphs, together with other data from the weather station like temperature and humidity

The tube’s output signal is converted into clean digital pulses to be counted by either an ESP32 or a Moteino R6, depending on the choice of wireless protocol. The ESP can make its data available through a web interface using its WiFi interface, while the Moteino can communicate through LoRa and sends out its data using MQTT. The resulting data is a counts-per-minute value which can be converted into an equivalent dose in Sievert using a simple conversion formula.

All design files are available on [Malte]’s website, including a PCB layout that neatly fits inside standard waterproof enclosures. Getting more radiation monitors out in the field can only be a good thing, as we found out when we tried to detect a radiation accident using community-sourced data back in 2019. Don’t like WiFi or LoRa? There’s plenty of other ways to connect your GM tubes to the internet.

Understanding Wavelets

September 10, 2022 by Al Williams 17 Comments

Mathematical transforms can be a great help in understanding signals. Imaging trying to look at a complex waveform and figuring out the frequency components without the Fourier transform. [Artem Kirsanov] calls the wavelet transform a “mathematical microscope” and his video gives you a great introduction to the topic. You can see the video below.

The video starts with a discussion about how the time domain and frequency domain have a dual relationship — not big news if you’ve dealt with Fourier transforms and — in fact — that’s the next topic in the video. However, there are limitations to the transformation — you lose time domain information in the process.

Continue reading “Understanding Wavelets” →

Frank Drake’s Legacy, Or: Are We All Alone In The Universe?

September 9, 2022 by Maya Posch 85 Comments

When Frank Drake began his astronomy career in the late 1950s, this was an incredibly exciting time for the field. Humanity was beginning to unlock the secrets of the Universe using ever more powerful radio frequency and optical telescopes, including the tantalizing prospect of space-based telescopes. Amidst the ramping up Space Race between the US and USSR, there was an ever-growing excitement about humankind’s future among the stars.

As concrete plans for landings and colonies on the Moon, Venus and Mars were proposed and put into action, it also brought to the forefront many existing and new questions about humanity’s place in the Universe. During Frank Drake’s 92 years on planet Earth – until his passing on September 2nd of this year – he was one of the driving forces behind the search for extraterrestrial intelligence (SETI), along with other legends like Carl Sagan.

Although to the average person the acronym SETI is most likely to bring to mind popcorn movies about little grey – or green – men, Drake’s Project Ozma, as well as the SETI Institution and the ongoing Breakthrough Listen project are just some of the attempts made by Drake and his colleagues over the decades to answer that one question that may affect the very course of humankind’s future: are we alone in the Universe?

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Don’t Be Salty: How To Make Desalination Work In Tomorrow’s World

September 8, 2022 by Maya Posch 60 Comments

Although water is often scarce for human consumption and agriculture, this planet is three-quarters covered by the stuff. The problem is getting the salt out, and this is normally done by the Earth’s water cycle, which produces rain and similar phenomena that replenish the amount of fresh water. Roughly 3% of the water on Earth is fresh water, of which a fraction is potable water.

Over the past decades, the use of desalination has increased year over year, particularly in nations like Saudi Arabia, Israel and the United Arab Emirates, but parched United States states such as California are increasingly looking into desalination technologies. The obvious obstacles that desalination faces – regardless of the exact technology used – involve the energy required to run these systems, and the final cost of the produced potable water relative to importing it from elsewhere.

Other issues that crop up with desalination include the environmental impact, especially from the brine waste and conceivably marine life sucked into the intake pipes. As the need for desalination increases, what are the available options to reduce the power needs and environmental impact?

Continue reading “Don’t Be Salty: How To Make Desalination Work In Tomorrow’s World” →

Agrivoltaics Is A Land Usage Hack For Maximum Productivity

September 7, 2022 by Zoe Skyforest 53 Comments

Land tends to be a valuable thing. Outside of some weird projects in Dubai, by and large, they aren’t making any more of it. That means as we try to feed and power the ever-growing population of humanity, we need to think carefully about how we use the land we have.

The field of agrivoltaics concerns itself with the dual-use of land for both food production and power generation. It’s all about getting the most out of the the available land and available sunlight we have.

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Nanoparticles Rip Hydrogen From Water

September 5, 2022 by Al Williams 38 Comments

Hydrogen fuel is promising, and while there’s plenty of hydrogen in the air and water, the problem is extracting it. Researchers have developed a way to use aluminum nanoparticles to rip hydrogen out of water with no additional energy input. It does, however, require gallium to enable the reaction. The reaction isn’t unknown (see the video below), but the new research has some interesting twists.

Aluminum, of course, is cheap and plentiful. Gallium, not so much, but the process allows recovery and reuse of the gallium, so that makes it more cost-effective. There is a patent pending for the process and — of course — the real trick is making the aluminum nanoparticles. But if you have that, this is a simple way to extract hydrogen from water with no extra energy and at room temperature. Since the reaction of creating aluminum oxide and releasing hydrogen with gallium is pretty well-known, it appears the real research here is determining the optimal properties of the aluminum and the ratio of aluminum to gallium.

While gallium isn’t a common item around the typical hacker’s workshop — unless you count the stuff bound up in semiconductors — it isn’t that expensive and it is relatively easy to handle. Hydrogen, though, not so much — so if you do decide to use this method to produce hydrogen, be careful!

We’ve seen gallium robots and even an antenna. So if you do get some of the liquid metal, there are plenty of experiments to try.