WiFi Controlled Finger Dims Lights Over UDP

January 26, 2019 by Eric Evenchick 10 Comments

While WiFi controlled lights are readily available, replacing your lighting fixtures or switches isn’t always an option. [Thomas] ran into this issue with his office lights. For the developers in the office, these lights always seemed to run a little too bright. The solution? A 3D printed, WiFi controlled finger to poke the dimmer switch.

This little hack consists of a servo, a 3D printed arm and finger assembly, and a Wemos D1 Mini development board. The Wemos is a low cost, Arduino compatible development board based on the ESP8266. We’ve seen it used for a wide variety of hacks here on Hackaday.

For this device, the Wemos is used to listen for UDP packets on the company’s WiFi network. When it receives a packet, it tells the servo to push the dimming button for a specified amount of time. [Thomas] wrote a Slack bot to automatically send these packets. Now, when the lights are too bright, a simple message to the bot allows anyone to dim the lights without ever leaving the comfort of their desk. Sure, it’s not the most secure or reliable method of controlling lights, but if something goes wrong, the user can always get up and flip the switch the old fashioned way.

3D Printing An Entire Rocket

January 14, 2019 by Brian Benchoff 43 Comments

If you’re ever flying into LAX and have the left side window seat, just a few minutes before landing, look out the window. You’ll see a small airport just below you and what appears at first glance to be a smokestack. That’s not a smokestack, though: that’s a rocket, and that’s where SpaceX is building all their rockets. Already SpaceX has revolutionized the aerospace industry, but just down the street there’s another company that’s pushing the manufacturing of rocket engines a bit further. Relativity Space is building rockets. They’re 3D printing rocket engines, and they’re designing what could be the first rocket engine made on Mars.

Bryce Salmi is an avionics hardware engineer at Relatively Space, and he made it out to the 2018 Hackaday Superconference to tell us all about manufacturing rockets. It’s an entirely new approach to manufacturing rockets and rocket engines with a clean-slate design that could eventually be manufactured on Mars.

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Sugar As A Bed Adhesive For 3D Printing

January 5, 2019 by Lewin Day 59 Comments

3D printers, like most CNC machines, reward careful thought and trial and error. It’s important to use the correct machine settings and to prepare the build environment properly in order to get good results. Fused Filament Fabrication printers rely on melting plastic just so in the production of parts, and have their own set of variables to play with. [Mysimplefix] has been exploring various solutions to bed adhesion and found something that seems to work perfectly, right in the pantry.

That’s right, this solution to the problem of bed adhesion is more commonly stirred into your coffee every morning – it’s sugar. [Mysimplefix] shares their preferred process, consisting of first mixing up a sugar/water solution in the microwave, before applying it to the bed with a paper towel and allowing the water to evaporate off.

Several test prints are then shown, with major overhangs, to show the adhesive capabilities of the sugar. The results are impressive, with parts sticking well while the bed is hot, while being easy to remove once cool. The video deals with PLA, but we’d be interested to see the performance with other materials as well.

It’s a tidy solution, and we’d love to know your thoughts and experiences in the comments. We’ve had a good long think about adhesives ourselves, too.

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3D Printed Head Can Unlock Your Phone

December 19, 2018 by Al Williams 23 Comments

[Thomas Brewster] writes for Forbes, but we think he’d be at home with us. He had a 3D printed head made in his own image and then decided to see what phones with facial recognition he could unlock. Turns out the answer is: most of them — at least, those running Android.

The models tested included an iPhone X, an LG, two Samsung phones, and a OnePlus. Ironically, several of the phones warn you when you enroll a face that the method may be less secure than other locking schemes. Conversely, one phone had a faster feature that is known to make the phone less secure.

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Shape Shifting Structures Work With Magnets

December 15, 2018 by Brian McEvoy 12 Comments

In The Dark Knight, Lucius Fox shows Bruce Wayne a neat bit of memory weave fabric. In its resting state, it is a light, flexible material, but when an electrical current is applied, it pops into a pre-programmed shape. That shape could be a tent or a bat-themed paraglider. Science has not caught up to Hollywood in this regard, but the concept has been demonstrated in a material which increases its rigidity up to 318% within one second when placed in a magnetic field. Those numbers do not mean a lot by themselves, but increasing rigidity in a reversible, non-chemical way is noteworthy.

The high-level explanation is that hollow tubes are 3D printed and filled with magnetorheological fluid which becomes more viscous in the presence of a magnet because the ferrous suspended particles bunch up to form chains instead of sliding over one another. Imagine a bike tire filled with gel, and when you need a little extra traction the tire becomes softer, but when you are cruising on a paved trail, the tire becomes as hard as a train wheel to reduce friction. That could be darn handy in more places than building a fast bike.

Imploding Tiny 3D Prints

December 15, 2018 by Al Williams 10 Comments

If you think about 3D printing, the ultimate goal would be to lay down specific atoms or molecule and build anything. Despite a few lab demonstrations at that scale, generally, it is easier to print in the macro scale than the micro. While it won’t get down to the molecule level, implosion fabrication is a new technique researchers hope will allow you to print large things and then shrink them. The paper describing the process appeared in Science. If you don’t want to pay your way through the paywall, you can read a summary on NewScientist or C&EN. Or you can scour the usual sources.

The team at MIT uses the same material that is found in disposable diapers. A laser traces patterns and the light reacts to a chemical implanted in the diaper material (sodium polyacrylate). That material can swell to many times its normal size which is why it is used in diapers. In this case, though, the material is swollen first and then reduced back to normal size.

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Lessons Learned From A 1-Day RTL-SDR Enclosure Project

December 14, 2018 by Donald Papp 9 Comments

[ByTechLab] needed an enclosure for his R820T2 based RTL-SDR, which sports an SMA connector. Resolving to design and 3D print one in less than a day, he learned a few things about practical design for 3D printing and shared them online along with his CAD files.

The RTL-SDR is a family of economical software defined radio receivers, and [ByTechLab]’s’ enclosure (CAD files available on GrabCAD and STL on Thingiverse) is specific to his model. However, the lessons he learned are applicable to enclosure design in general, and a few of them specifically apply to 3D printing.

He started by making a basic model of the PCB and being sure to include all large components. With that, he could model the right voids inside the enclosure to ensure a minimum of wasted space. The PCB lacks any sort of mounting holes, so the model was also useful to choose where to place some tabs to hold the PCB in place. That took care of the enclosure design, but it also pays to be mindful of the manufacturing method so as to play to its strengths. For FDM 3D printing, that means most curved shapes and rounded edges are trivial. It also means that the biggest favor you can do yourself is to design parts so that they can be printed in a stable orientation without any supports.

This may be nothing that an experienced 3D printer and modeler doesn’t already know, but everyone is a novice at some point and learning from others’ experiences can be a real timesaver. For the more experienced, we covered a somewhat more in-depth guide to practical 3D printed enclosure design.

[ByTechLab]’s desire for a custom enclosure was partly because RTL-SDR devices come in many shapes and sizes, as you can see in this review of 19 different units (of which only 14 actually worked.)