It’s getting close to the time of year when we need to start carefully vetting projects here at Hackaday. After all, nobody likes to get punked by an early April Fool’s joke. But as silly as this outsized PC fan looks, it sure seems like a legit build, if a bit on the pointless side.
Then again, perhaps pointless is too harsh a word to use. This 500-mm fan is by [Angus] over at Maker’s Muse, and it represents a lot of design work to make it buildable, as well as workable and (mostly) safe. Using both CNC-cut MDF and printed parts, the fan is an embiggened replica of a normal-sized case fan. The fan’s frame had to be printed in four parts, which lock together with clever interlocking joints. Each of the nine blades locks into a central hub with sturdy-looking dovetails.
And sturdy is important, as the fan is powered by a 1,500 Watt brushless DC motor. With a 4:1 reduction thanks to a printed gear train, the fan spins at around 3,300 RPM, which makes a terrifying noise. There’s a little bit of “speed-wobble” evident, but [Angus] managed to survive testing. The fan, however, did not — the 3D-printed gears self-destructed after a full-speed test, but not before the fan did its best wind tunnel imitation. And the RGB LEDs looked great.
If you’ve ever had surgery, and you’re over a certain age, chances are good you’re familiar with the dreaded incentive spirometer. It’s a little plastic device with one or more columns, each of which has a plastic ball in it. The idea is to blow into the thing to float the balls, to ensure that your lungs stay in good shape and reduce the chance of pneumonia. This unique air-powered clock reminds us a little of that device, without all the pain.
Like a spirometer, [Nir Tasher]’s clock has three calibrated tubes, each big enough to hold a foam ball loosely. At the bottom of each tube is a blower whose motor is under PWM control. A laser rangefinder sits below each ball and measures its height; the measurement is used by a PID loop to control the speed of each fan and thus the height of each ball. The video below shows that the balls are actually pretty steady, making the clock easy to read. It doesn’t, however, reveal what the clock sounds like; we’re going to go out on a limb here and guess that it’s pretty noisy. Still, we think it’s a fantastic way to keep time, and unique in the extreme.
If you’re like us, the expanded polystyrene (EPS) foam inserts that protect many packages these days are a source of mixed feeling. On the one hand, we’re glad that stuff arrives intact thanks to the molded foam inserts. But it seems so wasteful, especially when chucking it in the garbage can. If only it could be effectively recycled.
It turns out that it can be, if you equip yourself with this spinning “sawblades of doom” EPS recycler. It comes by way of [HowToLou], who was looking for a way to insulate a wall on the cheap. Almost all commercially available insulating materials – fiberglass batts, blown-in cellulose, expanding polyisocyanurate – are pretty pricey. Foam packing pieces are pretty easy to come by, though, and usually free for the taking. [Lou]’s method of turning them into insulation is a box containing four circular saw blades mounted to a piece of threaded rod and spun by a cordless drill. The blades are mounted askew on the rod for better reduction of the foam; [Lou] chose to use wire to hold the blades down, while we’d have printed up some slanted arbors and bolted the blades down more firmly. A chicken wire prefilter keeps the big chunks from clogging a blower made from an old bathroom exhaust fan, which does a great job of filling the wall cavities with pulverized EPS nuggets. The video below has all the details.
Honestly, the box is a little scary, and we have doubts that [Lou] will be able to get enough foam to finish the job, but it’s still a clever little hack. Grinding things up seems to be a theme for him; check out his leaf collector or his apple cider press.
As [Marius Hornberger] was working in his woodshop, a thunderous bang suddenly rocked the space. A brief search revealed the blower for the dust collector had shifted several inches despite being stoutly fastened down. Turns out, the blower had blown itself up when one of the impeller fins came loose. Time to revise and build a bigger, better dust collector!
[Hornberger] is thorough in describing his process, the video series chronicles where he went astray in his original design and how he’s gone about improving on those elements. For instance, the original impeller had six fins which meant fewer points to bear the operating stresses as well as producing an occasionally uncomfortable drone. MDF wasn’t an ideal material choice here either, contributing to the failure of the part.
Anyone who heats with a wood stove knows that the experience is completely different from typical central heating. It’s not for everyone, though, and it’s certainly not without its trade-offs. One of the chief complaints is getting heat away from the stove and into other areas of the house, and many owners turn on an electric fan to circulate the heated air.
That’s hardly in the green nature of wood heating, though, and fans can be noisy. So something like this heat-powered stove-top fan can come in handy. Such fans, which use Peltier devices to power a small electric motor, are readily available commercially. [bongodrummer] thought that sounded like no fun, though, and created his own mostly from junk. The Peltier module was salvaged from an old travel fridge and mounted to a heat sink from a computer to harvest heat from the stove. The other side of the Peltier needs to have a heat sink to keep it cooler than the hot side, and [bongodrummer] chose an unconventional bit of salvage for the job — the cylinder of a chainsaw engine. The spark plug hole sprouts the mount for the fan motor, and the cooling fins help keep the Peltier cool. And to prevent overheating of the device, he added a surprise — a car cooling system thermostat to physically lift the device off the stove when it gets too hot. Genius!
The video below shows the build, which was not trivial. But we think the end results are worth it, and it reminds us a little of the woodstove generator we featured a while back.
[Seb Lee-Delisle]’s NES lightgun gave us pause as the effect is so cool we couldn’t quite figure out how he was doing it at first. When he pulls the trigger there erupts the beam of light Sci Fi has trained us to expect, then it explodes in a precision sunburst of laserlight at the other end as smoke gently trails from the end of the barrel. This is a masterpiece of hardware and trickery.
The gun itself is a gutted Nintendo accessory. It looks like gun’s added bits consist of two LED strips, a laser module (cleverly centered with two round heatsinks), a vape module from an e-cigarette, a tiny blower, and a Teensy. When he pulls the trigger a cascade happens: green light runs down the side using the LEDs and the vape module forms a cloud of smoke in a burst pushed by the motor. Finally the laser fires as the LEDs finish their travel, creating the illusion.
More impressively, a camera, computer, and 4W Laser are waiting and watching. When they see the gun fire they estimate its position and angle. Then they draw a laser sunburst on the wall where the laser hits. Very cool! [Seb] is well known for doing incredible things with high-powered lasers. He gave a fantastic talk on his work during the Hackaday Belgrade conference in April. Check that out after the break.
[EssentialCraftsman] is relatively new to YouTube, but he’s already put out some impressive videos. We really enjoyed an episode dedicated to a fixture in his shop, his large custom blacksmith’s forge.
The forge is a custom cast vault of refractory that sits on a platter of fire bricks suspended on a heavy-duty rotating frame. Two forced air natural gas burner provide the heat. The frame is plasma CNC cut steel welded together.
A lot of technical challenges had to be solved. How does one hold a couple hundred pound piece of refractory in such a way that it can be lifted, especially when any steel parts exposed to the heat of the forge would become plastic and fail? When the forge turns off, how do you keep the hot air in the forge from rising into the blowers and melting them? There were many more.
We were really impressed by the polished final appearance of the forge, and the cleverness of its design. Everything is well thought out, and you can even increase the height of the forge by propping it up on more fire bricks. We hope [EssentialCraftsman] will continue to produce such high quality videos. We also enjoyed his episode on Anvils as well as a weirdly informative tirade on which shape of stake (round or square) to use when laying out concrete jobs. Videos after the break.