The project didn’t start with the noble aim of realizing the hidden and underutilized quiescent nature of a smoke alarm, though. He wanted his range exhaust fan to turn on automatically when it was needed during his (and his family’s) cooking activities. The particular range has four speeds so he wired up four relays to each of the switches in the range and programmed a Particle Photon to turn them on based on readings from an MQ-2 gas-detecting sensor.
The sensor didn’t work as well as he had hoped. It was overly sensitive to some gasses like LPG which would turn the range on full blast any time he used his cooking spray. Meanwhile, it would drift and not work properly during normal cooking. He tried disabling it and using only a temperature sensor, which didn’t work well either. Finally, he got the idea to tear apart a smoke detector and use its sensor’s analog output to inform the microcontroller of the current need for an exhaust fan. Now that that’s done, [Ben] might want to add some additional safety features to his stovetop too.
A parts tumbler is a great tool to have around. But if you don’t use it all the time, it’s hard to justify dropping hundreds of dollars on one. Fortunately, there are many ways to make your own tumbler while tailoring it to meet the need. Because really, as long as you get the medium moving enough to abrade the parts, you’re good.
[Daniele]’s parts tumbler is cool because it’s fairly easy to make, it’s really quiet, and it does the job quickly. This tumbler moves the medium by using an imbalanced plastic fan, which [Daniele] created by drilling a hole through one of the blades and fastening a short bolt and nut through it. If you’ve ever tried to stop a washing machine from walking away, you may be thinking this is a strange idea, because now he’s got a 4500 RPM vibration machine scuttling about the shop. So really, the true genius of this build lies in the great pains [Daniele] took to absorb all that vibration.
He’s got the fan float-mounted on rubber-lined springs and rubber mats under the washers involved in connecting the latching plastic box to the fan. Our favorite anti-vibration features are the twist-lock power connector and the custom silicone feet made from Motorsil D and cap bolts. We don’t know what the medium is here, but it’s got us thinking Grape-Nuts might work. Blow past the break to chew on the build video.
2D design and part fabrication doesn’t limit one to a 2D finished product, and that’s well-demonstrated in these Faux Aircon Units [Martin Raynsford] created to help flesh out the cyberpunk-themed Null Sector at the recent 2018 Electromagnetic Field hacker camp in the UK. Null Sector is composed primarily of shipping containers and creative lighting and props, and these fake air conditioner units helped add to the utilitarian ambiance while also having the pleasant side effect of covering up the occasional shipping container logo. Adding to the effect was that the fan blades can spin freely in stray air currents; that plus a convincing rust effect made them a success.
The units are made almost entirely from laser-cut MDF. The fan blades are cut from the waste pieces left over from the tri-pronged holes, and really showing off the “making 3D assemblies out of 2D materials” aspect are the fan hubs which are (with the exception of bearings) made from laser-cut pieces; a close-up of the hubs is shown here.
Capping off the project is some paint and the rusted appearance. How did [Martin] get such a convincing rust effect? By using real rust, as it turns out. Some cyanoacrylate glue force-cured with misted water for texture, followed by iron powder, then vinegar and hydrogen peroxide with a dash of salt provided the convincing effect. He was kind enough to document the fake rust process on his blog, complete with photos of each stage.
Null Sector showcased a range of creativity; it’s where this unusual headdress was spotted, a device that also showed off the benefits of careful assembly and design.
There are many annoying issues associated with desktop 3D printers, but perhaps none are trickier than keeping the machine at the proper temperature. Too cold, and printed parts can warp or fail to adhere to the bed. Too hot, and the filament can get soft and jam, or the motors will start clanking and missing steps. High-end industrial 3D printers have temperature-controlled enclosures for precisely this reason, but the best you can hope for with a printer that’s little more than some aluminum extrusion and an Arduino is a heated bed that helps but is no substitute for the real thing.
Like many 3D printer owners chasing perfect prints, [Stephen Thone] ended up putting his machine into a DIY enclosure to help keep it warm. Unfortunately, there gets to be a point when things get a little too hot inside the insulating cube. To address this issue, he put together a simple but very elegant temperature controlled fan to vent the enclosure when the internal conditions go above the optimal temperature.
[Stephen] picked up the digital temperature controller on Amazon for about $4 USD, and found a 60mm fan in the parts bin. He then came up with a clever two-part printed enclosure that slides together to make the fan and controller one unit which he can place in a hole he cut in the enclosure.
A lot of attention was paid to the front panel of the device, including mid-print filament swaps to create highlighted text and separate buttons printed in different colors. The end result is a very professional looking interface that involved relatively little manual labor; often a problem when trying to come up with nice looking panels.
We’ve all been there: you need a specific tool or gadget to complete a project, but it’s not the kind of thing you necessarily want to fork over normal retail price for. It could be something you’re only going to use once or twice, or maybe you’re not even sure the idea is going to work and don’t want to invest too much money into it. You cast a skeptical towards the ever-growing pile of salvaged parts and wonder…
Inspiration and a dig through the junk bin is precisely how [Nixie] built this very impressive spin coater for use in his ongoing homemade semiconductor project. If you’ve never had first hand experience with a spin coater, don’t worry, not many people have. Put simply, it’s a machine that allows the user to deposit a thin layer of material on a disc by way of centrifugal force. Just place a few drops in the center of the disc, then spin it up fast enough and let physics do the rest.
[Nixie] only needs to spin up a fairly tiny disc, and realized the hub of a 40x40mm brushless case fan was just about the perfect size. A quick pass through the lathe stripped the hub of its blades and faced off the front. Once he found a tube that was the exact same diameter of the fan’s axle, he realized he could even use a small vacuum pump to hold his disc in place. A proper seal is provided by 10 and 16 mm OD o-rings, installed into concentric grooves he machined into the face of the hub.
With a way to draw a vacuum through the hub of the spinner he just needed the pump. As luck would have it, he didn’t have to wait for one to make the journey from China, as he had one of those kicking around his junk bin from a previous project. The only thing he ended up having to buy was the cheap PWM fan controller which he mounted along with the modified fan to a piece of black acrylic; producing a fairly professional looking little piece of lab equipment. Check out the video after the break for a brief demonstration of it in action.
The entry-level 3D-printer market is a rich one, with offerings from many vendors that are surprisingly good. But nothing is perfect, and to hit the $200 price point some compromises are inevitable. That doesn’t mean you have to live with those engineering choices, of course, which makes these cheap printers a great jumping off point for aftermarket mods.
[Linas K] took this route and in the process made his Cetus 3D-printer essentially silent. The first part of the video below reviews the shortcomings of the stock machine and the mechanical changes [Linas] made, including new brackets for the Z-axis slide, relocating the WiFi antenna to someplace sensible, and adding limit switches for each slide. Inside the case, the electronics get a complete reworking, with a custom PCB to house Trinamic stepper drivers for ultraquiet operation. The new board also supports the limit switches as well as thermostatic control of the extruder fan and pads for a platform heater. As a bonus, the new PCB is much smaller than the original, leaving room to tuck the power supply into the case, which is a nice touch. It wasn’t cheap, and it meant basically gutting the printer, but the results are impressively quiet.
[Mark Rehorst] has been on the hunt for the perfect 3D printer cooling fan and his latest take is a really interesting design. He’s printed an impeller and housing, completing the fan using a hard drive motor to make it spin.
We should take a step back to see where this all began. Many 3D printers us a cooling fan right at the tip of the extruder because the faster you faster you cool the extruded filament, the fewer problems you’ll have with drooping and warping. Often this is done with a small brushless fan mounted right on the print head. But that adds mass to the moving head, contributing to problems like overshoot and oscillation, especially on larger format printers that have longer gantries. [Mark] just happens to have an enormous printer we covered back in January and that’s the machine this fan targets.
Make sure you give [Mark’s] Mother of all print cooling fansarticle a look. His plan is to move the fan off of the print head and route a flexible tube instead. He tried a couple of fans, settling on one he pulled from a CPAP machine (yes the thing you wear at night to combat sleep apnea) found in the parts bin at Milwaukee Makerspace. It works great, moving quite a bit more air than necessary. The problem is these CPAP parts aren’t necessarily easy to source.
You know what is easy to source? Old hard drives. [Mark] mentions you likely have one sitting around and if not, your friends do. We have to agree with him. Assuming you already have a 3D printer (why else do you want to print this fan?), the only rare part in this mix is the ESC to make the motor spin. Turns out we just saw a BLDC driver build that would do the trick. But in [Mark’s] case he found a rather affordable driver that suits his needs which is used in the video demo below.