Building A Sound Activated Shop Fan With Arduino

Whether you’re using a soldering iron or a table saw, ventilation in the shop is important. Which is why [Atomic Dairy] built a monster air cleaner called the Fanboy that looks like it should be mounted under the wing of an F-15. Realizing a simple switch on the wall wouldn’t do this potent air mover justice, they decided to build a sound activated controller for it.

It’s certainly an elegant idea. The sound created once they kick on their woodworking tools would be difficult to miss by even the most rudimentary of sound-detection hardware. At the most basic level, all they needed was a way for an Arduino to throw a relay once the noise level in the room reached a specific threshold.

Of course it ended up getting a bit more complicated than that, as tends to happen with these kinds of projects. For one, the sound doesn’t directly control the solid state relay used in the fan controller. When the microphone equipped Arduino detects enough noise, it will start a timer that keeps the fan running for two hours. If the tool keeps running, then more time gets added to the clock. This ensures that the air in the room is well circulated even after the cutting and sanding is done.

[Atomic Dairy] also added a few additional features so they could have more direct control over the fan. There’s a button to manually add more time to the clock, and another button to shut it down. There’s even support for a little wireless remote control, so the fan can be operated without having to walk over to the control panel.

We’ve seen some impressive air circulation and dust collection systems over the years, but finding a way to elegantly switch them on and off has always been a problem given the wide array of tools that could be in use at any given time. Sound activation isn’t a perfect solution, but it’s certainly one we’d consider for our own shop.

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Ask Hackaday: What’s Your Coronavirus Supply Chain Exposure?

In whichever hemisphere you dwell, winter is the time of year when viruses come into their own. Cold weather forces people indoors, crowding them together in buildings and creating a perfect breeding ground for all sorts of viruses. Everything from the common cold to influenza spread quickly during the cold months, spreading misery and debilitation far and wide.

In addition to the usual cocktail of bugs making their annual appearance, this year a new virus appeared. Novel coronavirus 2019, or 2019-nCoV, cropped up first in the city of Wuhan in east-central China. From a family of viruses known to cause everything from the common cold to severe acute respiratory syndrome (SARS) in humans, 2019-nCoV tends toward the more virulent side of the spectrum, causing 600 deaths out of 28,000 infections reported so far, according to official numbers at the time of this writing.

(For scale: the influenzas hit tens of millions of people, resulting in around four million severe illnesses and 500,000 deaths per season, worldwide.)

With China’s unique position in the global economy, 2019-nCoV has the potential to seriously disrupt manufacturing. It may seem crass to worry about something as trivial as this when people are suffering, and of course our hearts go out to the people who are directly affected by this virus and its aftermath. But just like businesses have plans for contingencies such as this, so too should the hacking community know what impact something like 2019-nCoV will have on supply chains that we’ve come to depend on.

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A French Press You Can Take Out Camping

There’s many a hacker that considers coffee a necessary fuel, without which, little work can be achieved. This applies whether in the office or traipsing around in the great outdoors. For the latter situation, [Poehls05] developed a robust French press that’s well suited to field use.

Typically, a French press consists of a plunger assembly which moves within a glass vessel. This is fragile and unwieldy for throwing in a backpack. Instead, in this design, the plunger assembly is harvested from an existing press and repurposed to fit within a sturdy Nalgene water bottle, designed specifically for overlanding.

The modifications involve cutting the existing press plate into three slices, and reassembling with hinges so it may fold. The plunger rod is then modified to make it possible to tilt the press plate relative to the rod. These modifications allow the plunger to be slid into the narrower neck of the Nalgene water bottle, and also enable the plunger rod to work with the original screw-down lid. In this configuration, the bottle is no longer water tight, but can be converted to normal use by swapping a regular lid back on top.

With the changes in place, the plastic bottle can easily be used in the same manner as a regular French press. Simply fill with hot water, allow the grounds to steep, and then press and pour. It’s a great way to make high-quality coffee in the wilderness, and one that may prove popular with hackers who don’t wish to give up the finer things when out and about. We’ve also featured tricks to make the most of hotel coffee, too.

Bringing A Swap Meet 3D Printer Back From The Dead

At a recent swap meet, [digitalrice] found what appeared to be a like-new QIDI X-Plus 3D printer. It wasn’t clear what was wrong with it, but considering it retails for $900 USD, he figured the asking price of $150 was worth the gamble. As you might expect, the printer ended up being broken. But armed with experience and a supply of spare parts, he was able to get this orphaned machine back up and running.

The first and most obvious problem was that the printer’s Z axis didn’t work properly. When the printer tried to home the axis, one of the motors made a terrible noise and the coupler appeared to be spinning backwards. From his experience with other printers, [digitalrice] knew that the coupler can slip on the shaft, but that didn’t appear to be the case here. Removing the stepper motor and testing it in isolation from the rest of the machine, he was able to determine it needed replacing.

Improving the printer’s filament path.

Unfortunately, the spare steppers he had weren’t actually the right size. Rather than waiting around for the proper one to come in the mail, he took an angle grinder to the stepper’s shaft and cut off the 5 mm needed to make it fit, followed by a few passes with a file to smooth out any burrs. We’re not sure we’d recommend this method of adjustment under normal circumstances, but we can’t argue with the results.

The replaced Z motor got the printer moving, but [digitalrice] wasn’t out of the woods yet. At this point, he noticed that the hotend was hopelessly clogged. Again relying on his previous experience, he was able to disassemble the extruder assembly and free the blob of misshapen PLA, leading to test prints which looked very good.

But success was short lived. After swapping to a different filament, he found it had clogged again. While clearing this second jam, he realized that the printer’s hotend seemed to have a design flaw. The PTFE tube, which is used to guide the filament down into the hotend, didn’t extend far enough out. Right where the tube ended, the filament was getting soft and jamming up the works. With a spare piece of PTFE tube and some manual reshaping, he was able to fashion a new lining which would prevent the filament from softening in this key area; resulting in a more reliable hotend than the printer had originally.

It’s great to see this printer repaired to working condition, especially since it looks like [digitalrice] was able to fix a core design flaw. But a broken 3D printer can also serve as the base for a number of other interesting projects, should you find yourself in a similar situation. For example, replacing the extruder assembly with a digital microscope can yield some very impressive results.