3D Printed Sneakers Are Now A Thing

October 5, 2018 by Lewin Day 20 Comments

Shoes may seem simple at face value, but are actually rather complex. To create a comfortable shoe that can handle a full day of wear without causing blisters, as well as deal with the stresses of running and jumping and so on, is quite difficult. Is it possible to create a shoe that can handle all that, using a 3D printer?

[RCLifeOn] discovered these sneakers by [Recreus] on Thingiverse, and decided to have a go printing them at home. While [Recreus] recommend printing the shoes in their Filaflex material, for this build, one shoe was printed in thermoplastic polyurethane, the other in Ninjaflex. As two filaments that are both commonly known to be pliable and flexible, the difference in the final parts is actually quite significant. The Ninjaflex shoe is significantly more flexible and cushions the foot better, while the rigidity of the TPU shoe is better for ankle support.

Our host then takes the shoes on a long run through the woods, battling dirt, mud, and other undesirables. Both shoes hold up against the abuse, although [RCLifeOn] notes that the Ninjaflex shoe is much more comfortable and forgiving for longer duration wear.

We’ve seen other 3D printed shoe hacks before, too – like these nifty shoelace locks.

Fully 3D Printed And Metalized Horn Antennas Are Shiny And Chrome

October 4, 2018 by Brian Boucheron 19 Comments

We’ve seen our share of 3D printed antennas before, but none as well documented and professionally tested as [Glenn]’s 3D printed and metalized horn antennas. It certainly helps that [Glenn] is the principal engineer at an antenna testing company, with access to an RF anechoic chamber and other test equipment.

Horn antennas are a fairly simple affair, structurally speaking, with a straight-sided horn-shaped “cone” and a receptacle for standardized waveguide or with an appropriate feed, coaxial adapters. They are moderately directional and can cover a wide range of frequencies. These horns are often used in radar guns and as feedhorns for parabolic dishes or other types of larger antenna. They are also used to discover the cosmic microwave background radiation of our universe and win Nobel Prizes.

[Glenn]’s antennas were modeled in Sketchup Make, and those files plus standard STL files are available for download. To create your own horn, print the appropriate file on a normal consumer-grade fused deposition printer. For antennas that perform well in WiFi frequency ranges you may need to use a large-format printer, as the prints can be “the size of a salad bowl”. Higher frequency horns can easily fit on most print beds.

After printing, [Glenn] settled on a process of solvent smoothing the prints, then metalizing them with commonly available conductive spray paints. The smoothing was found to be necessary to achieve the expected performance. Two different paints were tested, with a silver-based coating being the clear winner.

The full write-up has graphs of test results and more details on the process that led to these cheap, printed antenna that rival the performance of more expensive commercial products.

If you’re interested in other types of 3D printed antenna, we’ve previously covered a helical satcom feed, a large discone antenna, and an aluminum-taped smaller discone antenna.

The N64 Controller Gets Brass Gears Through 3D Printing

September 21, 2018 by Brian Benchoff 36 Comments

The controller for the Nintendo 64 is a masterpiece of design, and despite being more than two decades old, people are still using this controller competitively. Smash Bros, you know. Those competitive gaming enthusiasts are hard on their controllers, and after decades and tournaments, the analog stick will wear out. Previously, this required a rebuild or simply replacing the entire controller. Now there’s another option: a completely re-engineered analog stick, all made possible thanks to 3D printing.

[Nam Le] is a student at Cal Poly, and as would be expected for a very specific subset engineering students, had to track down new N64 controller every few months. The stick on these controllers wear out, so [Nam] decided to make the most durable joystick that has ever fit inside an N64 controller.

The design of the N64 stick is pretty simple, and exactly what you would expect if you’ve ever opened up an analog joystick. There’s the stick itself, which is connected to gears on the X and Y axes, which are in turn connected to encoders. This entire assembly sits in a bowl. After twenty years, the mating surface between the stick and the gears wear down, and the bowl becomes deformed. The solution here is obviously to engineer something sturdier, and despite what most of the 3D printing community will tell you, ABS and PLA just won’t cut it.

[Nam] re-designed the gears and bowl out of brass using lost-wax casting using 3D printed parts. These brass parts were mated with 3D printed gears and an enclosure for the bowl. The stick is nylon, an important design choice because this is the first part to wear down anyway, and it’s also the easiest part to replicate. Yes, this is designing an analog stick for the strength of materials and Real Engineering™ for those of you keeping track at home.

Right now, the joystick works as intended, and lasts much longer than the stock version. The goal now is to get this stick tournament-legal for some serious Smash time, in the hopes of not replacing controllers every few months.

HP Rolls Out Metal 3D Printers

September 14, 2018 by Al Williams 36 Comments

You normally think of HP as producing inkjet and laser printers. But they’ve been quietly building 3D printers aimed at commercial customers. Now they are moving out with metal printers called — predictably — the HP Metal Jet. The video (see below) is a little glitzy, but the basic idea is that print bars lay down powder on a 21-micron grid. A binding agent prints on the powder, presumably in a similar way to a conventional inkjet printer. A heat source then evaporates the liquid from the binder.

The process repeats for each layer until you remove the part and then sinter it using a third-party oven-like device. According to HP, their technique has more uniform material properties than fusing the powder on the bed with a laser. They also claim to be much faster than metal injection molding.

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Awesome Looking 3D Printed RC Plane Is Full Of Design Considerations

September 11, 2018 by Steven Dufresne 18 Comments

Designing and 3D printing RC planes offer several interesting challenges, and so besides being awesome looking and a fast flier, [localfiend’s] Northern Pike build is definitely worth a look. Some details can be found by wading through this forum but there’s also quite a bit on his Thingiverse page.

Tongue-and-groove joint for the wing — Tongue-and-groove joint

Naturally, for an RC plane, weight is an issue. When’s the last time you used 0% infill, as he does for some parts? Those parts also have only one perimeter, making this thin-walled-construction indeed. He’s even cut out circles on the spars inside the wings. For extra strength, a cheap carbon fiber arrow from Walmart serves as a spar in the main wing section. Adding more strength yet, most parts go together with tongue-and-groove assembly, making for a stronger join than there would be otherwise. This slotted join also acts as a spar where it’s done for two wing sections. To handle higher temperatures, he recommends PETG, ABS, ASA, Polycarbonate, and nylon for the motor mount and firewall while the rest of the plane can be printed with PLA.

As you can tell from the videos below, [localfiend’s] flier is a high-performance 3D printed machine. But such machines don’t have to be relegated to the air as this RC jet boat demonstrates. Though some do hover on a thin cushion of air.

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No Signal For Your Radio-Controlled Watch? Just Make Your Own Transmitter

September 10, 2018 by Ben James 38 Comments

You can win any argument about the time when you have a radio controlled watch. Or, at least, you can if there’s any signal. [Henner Zeller] lives in a place where there is no reception of the DCF77 signal that his European wristwatch expects to receive. Consequently, he decided to make his own tiny transmitter, which emulates the DCF77 signal and allows the watch to synchronise.

A Raspberry Pi Zero W is the heart of the transmitter, and [Henner] manages to coax it into generating 77500.003Hz on a GPIO pin – close enough to the 77.5kHz carrier that DCF77 uses. The signal is AM, and transmits one bit/s, repeating every minute. A second GPIO performs the required attenuation, and a few loops of wire are sufficient for an antenna which only needs to work over a few inches. The Raspberry Pi syncs with NTP Stratum 1 servers, which gives the system time an accuracy of about ±50ms. The whole thing sits in a slick 3D printed case, which provides a stand for the watch to rest on at night; this means that every morning it’s synchronised and ready to go.

[Henner] also kindly took the time to implement the protocols for WWVB (US), MSF (UK) and JJY (Japan). This might be just as well, given that we recently wrote about the possibility of WWVB being switched off. Be sure to check the rules in your area before giving this a try.

We’ve seen WWVB emulators before, like this ATtiny45 build, but we love that this solution is an easy command line tool which supports many geographical locations.

Hummingbirds, 3D Printing, And Deep Learning

August 31, 2018 by Ben James 15 Comments

Setting camera traps in your garden to see what local wildlife is around is quite popular. But [Chris Lam] has just one subject in mind: the hummingbird. He devised a custom setup to capture the footage he wanted using some neat tech.

To attract the hummingbirds, [Chris] used an off-the-shelf feeder — no need to re-invent the wheel there. To obtain the closeup footage required, a 4K action cam was used. This was attached to the feeder with a 3D-printed mount that [Chris] designed.

When it came to detecting the presence of a hummingbird in the video, there were various approaches that could have been considered. On the hardware side, PIR and ultrasonic distance sensors are popular for projects of this kind, but [Chris] wanted a pure software solution. The commonly used motion detection libraries for this type of project might have fallen over here, since the whole feeder was swinging in the air on a string, so [Chris] opted for machine learning.

A RESNET architecture was used to run a classification on each frame, to determine if the image contained a hummingbird or not. The initial attempt was not greatly successful, but after cropping the image to a smaller area around the feeder, classification accuracy greatly increased. After a bit of FFmpeg magic, the selected snippets were concatenated to make one video containing all the interesting parts; you can see the result in the clip after the break.

It seems that machine learning and wildlife cams are a match made in heaven. We’ve already written about a proof-of-concept project which identifies different animals in the footage when motion is detected.

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