Putting An Afterburner On An Electric Ducted Fan

September 17, 2021 by Lewin Day 30 Comments

Afterburners are commonly agreed to be the coolest feature of military fighter aircraft. Injecting raw fuel into the exhaust stream of a jet engine, afterburners are responsible for that red-hot flaming exhaust and the key to many aircraft achieving supersonic flight. [Integza] wanted to see if the same concept could be applied to an electric ducted fan, and set out to find out.

Of course, building an afterburner for an EDF does add a lot of complication. A flame tube was installed downstream of the EDF, fitted with a brass tube drilled carefully to act as a fuel injector. The flame tube was also fitted with an automotive glow plug in order to ignite the fuel, which was lighter refill gas straight from a can. The whole assembly is wrapped up inside a clear acrylic tube that allows one to easily see what’s happening inside with the combustion.

Results were mixed. While the fuel did combust, but in a rather intermittent fashion. In proper operation, an afterburner would run with smooth, continuous, roaring combustion. Additionally, no thrust measurements were taken and the assembly barely shook the desk.

Thus, if anything, the video serves more as a guide of how to burn a lot of lighter gas with the help of an electric fan. The concept does has merit, and we’ve seen past attempts, too, but we’d love to see a proper set up with thrust readings with and without the afterburner to see that it’s actually creating some useful thrust. Video after the break. Continue reading “Putting An Afterburner On An Electric Ducted Fan” →

DIY Laser Speckle Imaging Uncovers Hidden Details

September 17, 2021 by Tom Nardi 31 Comments

It sure sounds like “laser speckle imaging” is the sort of thing you’d need grant money to experiment with, but as [anfractuosity] recently demonstrated, you can get some very impressive results with a relatively simple hardware setup and some common open source software packages. In fact, you might already have all the components required to pull this off in your own workshop right now and just not know it.

Anyone who’s ever played with a laser pointer is familiar with the sparkle effect observed when the beam shines on certain objects. That’s laser speckle, and it’s created by the beam reflecting off of microscopic variations in the surface texture and producing optical interference. While this phenomenon largely prevents laser beams from being effective direct lighting sources, it can be used as a way to measure extremely minute perturbations in what would appear to be an otherwise flat surface.

In this demonstration, [anfractuosity] has combined a simple red laser pointer with a microscope’s 25X objective lens to produce a wider and less intense beam. When this diffused beam is cast onto a wall, the speckle pattern generated by the surface texture can plainly be seen. What’s not obvious to the naked eye is that touching the wall with your hand actually produces a change in the speckle pattern. But if you take high-resolution before and after shots, the images can be run through OpenCV to highlight the differences and reveal a ghostly hand-print.

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Retrotechtacular: The Dangers Of Confined Spaces

September 17, 2021 by Lewin Day 31 Comments

Many people find themselves working in confined spaces every day, whether it be in sewer systems, drains, or other tight spots. These areas come with their own unique risks to life and limb that must be carefully considered in order to avoid disaster.

To this end, the Worker’s Compensation Board of British Columbia, known as WorkSafe BC, produced a video on the dangers of working in these areas. Confined Spaces, Deadly Spaces highlights how these areas can kill, and the right way to work around these hazards.

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Hackaday Podcast 136: Smacking Asteroids, Decoding Voyager, Milling Cheap, And PS5 Triggered

September 17, 2021 by Mike Szczys 2 Comments

Hackaday editors Elliot Williams and Mike Szczys look back on a great week of hardware hacking. What a time to be alive when you can use open source tools to decode signals from a probe that has long since left our solar system! We admire two dirt-cheap builds, one to measure current draw in mains power, another to mill small parts with great precision for only a few bucks. A display built from a few hundred 7-segment modules begs the question: who says pixels need to be the same size? We jaw on the concept of autonomous electric cargo ships, and marvel at the challenges of hitting an asteroid with a space probe. All that and we didn’t even mention using GLaDOS as a personal assistant robot, but that’s on the docket too!

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (60 MB or so.)

Continue reading “Hackaday Podcast 136: Smacking Asteroids, Decoding Voyager, Milling Cheap, And PS5 Triggered” →

RoboTray Is A Secret Tea Butler

September 17, 2021 by Kristina Panos 10 Comments

How far would you go for your cup of tea? [samsungite]’s missus doesn’t like clutter on her countertops, so away the one-cup kettle would go back into the cupboard for next time while the tea steeped. As long as there’s room for it in there, why not install it there permanently? That’s the idea behind RoboTray, which would only be cooler if it could be plumbed somehow.

RoboTray went through a few iterations, most importantly the switch from 6mm MDF to 4 mm aluminum plate. A transformer acts as a current sensor, and when the kettle is powered on, the tray first advances forward 7 cm using a 12 VDC motor and an Arduino. Then it pivots 90° on a lazy Susan driven by another 12 VDC motor. The kettle is smart enough to turn itself off when finished, and the Arduino senses this and reverses all the steps after a ten-second warning period. Check it out in action after the break.

If [samsungite] has any more Arduinos lying around, he might appreciate this tea inventory tracker.

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This Week In Security: Office 0-day, ForcedEntry, ProtonMail, And OMIGOD

September 17, 2021 by Jonathan Bennett 10 Comments

A particularly nasty 0-day was discovered in the wild, CVE-2021-40444, a flaw in how Microsoft’s MSHTML engine handled Office documents. Not all of the details are clear yet, but the result is that opening a office document can trigger a remote code execution. It gets worse, though, because the exploit can work when simply previewing a file in Explorer, making this a potential 0-click exploit. So far the attack has been used against specific targets, but a POC has been published.

It appears that there are multiple tricks that should be discrete CVEs behind the exploit. First, a simple invocation of mshtml:http in an Office document triggers the download and processing of that URL via the Trident engine, AKA our old friend IE. The real juicy problem is that in Trident, an iframe can be constructed with a .cpl URI pointing at an inf or dll file, and that gets executed without any prompt. This is demonstrated here by [Will Dormann]. A patch was included with this month’s roundup of fixes for Patch Tuesday, so make sure to update. Continue reading “This Week In Security: Office 0-day, ForcedEntry, ProtonMail, And OMIGOD” →

Add-On Lets FDM 3D Printer Wash And Cure Resin Parts

September 17, 2021 by Tom Nardi 5 Comments

The dramatic price reductions we’ve seen on resin 3D printers over the last couple of years have been very exciting, as it means more people are finally getting access to this impressive technology. But what newcomers might not realize is that the cost of the printer itself is only part of your initial investment. Resin printed parts need to be washed and cured before they’re ready to be put into service, and unless you want to do it all by hand, that means buying a second machine to do the post-printing treatment.

Not sure he wanted to spend the money on a dedicated machine just yet, [Chris Chimienti] decided to take an unusual approach and modify one of his filament-based 3D printers to handle wash and cure duty. His clever enclosure slips over the considerable Z-axis of a Anet ET5X printer, and includes banks of UV LEDs and fans to circulate the air and speed up the drying process.

The curing part is easy enough to understand, but how does it do the washing? You simply put a container of 70% isopropyl alcohol (IPA) on the printer’s bed, and place the part to be washed into a basket that hangs from the printer’s extruder. Custom Python software is used to generate G-code that commands the printer to dip the part in the alcohol and swish it back and forth to give it a good rinse.

Once the specified time has elapsed, the printer raises the part up into the enclosure and kicks on the LEDs to begin the next phase of the process. The whole system is automated through an OctoPrint plugin, and while the relatively low speed of the printer’s movement means the “washing” cycle might not be quite as energetic as we’d like, it’s definitely a very slick solution.

[Chris] provides an extensive overview of the project in the latest video on his YouTube channel, Embrace Racing. In it he explains that the concept could certainly be adapted for use on printers other than the Anet ET5X, but that it’s considerable build volume makes it an ideal candidate for conversion. Of course it’s also possible to use the foam board enclosure by itself as a curing chamber, though you’ll still need to wash the part in IPA ahead of time.

This is perhaps one of the most unusual wash and cure systems we’ve seen here at Hackaday, but we appreciate the fact that [Chris] based the whole thing on the idea that you’ve probably got a FDM printer sitting nearby that otherwise goes unused when you’re working with resin. If that’s not the case for you, putting together a more traditional UV curing chamber is an easy enough project.

Continue reading “Add-On Lets FDM 3D Printer Wash And Cure Resin Parts” →