3D Printed Bicycle Tire Not Full Of Hot Air

To show off its new TPU filament called PRO FLEX, BigRep GmbH posted a video showing a 3D printed bike tire that uses a flexible plastic structure instead of air. The video shows them driving the bike around Berlin.

According to the company, the filament will allow the creation of a large number of industrial objects not readily built with other types of plastic. Their release claims the material has high temperature resistance, low temperature impact resistance, and is highly durable. Applications include gear knobs, door handles, skateboard wheels, and other flexible parts that need to be durable.

The material has a Shore 98 A rating. By way of comparison, a shoe heel is typically about 80 on the same scale and an automobile tire is usually around 70 or so. The hard rubber wheels you find on shopping carts are about the same hardness rating as PRO FLEX.

Obviously, a bicycle tire is going to take a big printer. BigRep is the company that makes the BigRep One which has a large build volume. Even with a wide diameter tip, though, be prepared to wait. One of their case studies is entitled, “Large Architectural Model 3D Printed in Only 11 Days.” Large, in this case, is a 1:50 scale model of a villa. Not tiny, but still.

We’ve looked at other large printers in the past including 3DMonstr, and the Gigimaker. Of course, the latest trend is printers with a practically infinite build volume.

Continue reading “3D Printed Bicycle Tire Not Full Of Hot Air”

AH-1 Cobra Tap Handle Pours On The Fun

Ayn Rand said, “If it’s worth doing, it’s worth overdoing.” As far as we’re concerned those are words to live by, and something that’s exemplified by most of the posts on this site. She also said some really suspect stuff about the disabled and Native Americans and reality, but you’ve got to take the good with the bad and all that.

We don’t know how much Rand [Will Weber] has read, but we’re willing to bet he’d agree about overdoing it. He recently documented a very cool 3D printed tap handle that’s designed to look like the B8 flight stick from an AH-1 Cobra helicopter. But this is no static piece of plastic, in the video after the break, he demonstrates how each button on the flight stick triggers a different weapons sound effect.

The 3D print is separated up into a number of sections so that the stick can be assembled in pieces. Not only does this make it an easier print, it also allows for the installation of the electronics.

For the Arduino aficionados out there, we have some bad news. Rather than putting in a general purpose microcontroller, [Will] went the easy route and used an Adafruit Audio FX Mini Sound Board. These boards have their own onboard storage for the audio files and don’t require a microcontroller to function. It makes it super easy to add sound effects or even music to your projects; just pair it with a power supply, a couple of buttons, and a speaker.

The finish work on the printed parts looks excellent. We can only imagine how much fun [Will] had sanding inside all the little nooks and crannies to get such a smooth final result. While some might complain about the idea of a tap handle needing to be recharged occasionally, we think the satisfaction of firing off a few rockets every time you grab a glass is more than worth it.

While this isn’t the first unique tap handle we’ve covered here at Hackaday, it’s certainly the most flight-ready. Continue reading “AH-1 Cobra Tap Handle Pours On The Fun”

Algorithms For Visual Learners

Computer programming is a lot like chess. It is fairly simple to teach people the moves. But knowing how the pieces move isn’t the reason you can win. You have to understand how the pieces work together. It is easy to learn the mechanics of a for loop or a Java interface. But what makes programs work are algorithms. There are many books and classes dedicated to algorithms, but if you are a visual learner, you might be interested in a site that shows visualizations of algorithms called VisuAlgo.

The site is from [Dr. Steven Halim] and is meant for students at the National University of Singapore, but it is available “free of charge for Computer Science community on earth.” We suspect if any astronauts or cosmonauts wanted to use it in space, they’d be OK with that, too.

The animations and commentary take you through algorithms ranging from the common — sorting and linked lists — to the obscure — Steiner and Fenwick trees. Each animation frame has some commentary, so it isn’t just pretty pictures. The site is available in many languages, too.

Many of the animations allow you to set up problems and execute them using a C-like pseudo language. When it executes, you can watch the execution pointer and a box comments on the current operation. For example, in the linked list unit, you can create a random doubly linked list and then search it for a particular value. Not only can you see the code, but the graphical representation of the list will update as the code runs.

The site allows you to register for free to get additional features, but we didn’t and it was still a great read about many different data structures. Also, a few of the commentary slides require you to show you are actually a computer science professor — we assume there’s some copyright issue involved because it is only a few.

This site is a great example of how many free educational resources are out there on the web. It isn’t just computer science either. MITx — or more generally, edX — has some great hardware classes and many other topics

The Adafruit Feather Is A Thing

A few years ago, Adafruit launched the Feather 32u4 Basic Proto. This tiny development board featured — as you would expect — an ATMega32u4 microcontroller, a USB port, and a battery charging circuit for tiny LiPo batteries. It was, effectively, a small Arduino clone with a little bit of extra circuitry that made it great for portable and wearable projects. In the years since, and as Adafruit has recently pointed out, the Adafruit Feather has recently become a thing. This is a new standard. Maxim is producing compatible ‘wings’ or shields. If you’re in San Francisco, the streets are littered with Feather-compatible boards. What’s the deal with these boards, and why are there so many of them?

The reason for Adafruit’s introduction of the Feather format was the vast array of shields, hats, capes, clicks, props, booster packs, and various other standards. The idea was to bring various chipsets under one roof, give them a battery charging circuit, and not have a form factor that is as huge as the standard Arduino. The Feather spec was finalized and now we have three-phase energy monitors, a tiny little game console, LoRaWAN Feathers, and CAN controllers.

Of course, the Feather format isn’t just limited to Adafruit products and indie developers. The recently introduced Particle hardware is built on the Feather format, giving cellular connectivity to this better-than-Arduino format. Maxim is producing some development boards with the same format.

So, do we finally have a form factor for one-off embedded development that isn’t as huge or as wonky as the gigantic Arduino with weirdly offset headers? It seems so.

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Hackaday Links: May 6th 2018

Way back in the day, if you were exceptionally clever, you could just solder more RAM to your computer. You did this by taking a DIP, stacking it on top of an existing RAM chip, bending out the enable pin, and soldering everything down. Wire the enable pin to an address pin, and you have more RAM. [Eric] wanted to get a game running on a Tandy 1000A, but that computer just doesn’t have enough RAM. The solution was to stack the RAMs. It’s a human centipede of deadbugging skills.

We’ve mentioned this before, but I just received another copy of either the best or worst press release I’ve ever seen. Dateline George Town, Cayman Islands: Onstellar is a cryptocurrency-based social network focusing on the paranormal. Apparently, you can use a blockchain to talk about UFOs. It gets better, though: Onstellar will be exhibiting at the world’s largest UFO conference at the beginning of June, in the middle of the Mojave, where a bunch of Air Force and Navy planes are flying all the time. It seems like you would want to have a UFO conference where there’s a lower rate of false positives, right?

A Biohacker has died. Aaron Traywick was found dead in a sensory deprivation chamber in Washington DC this week. Traywick found fame as the CEO of Ascendance Biomedical and by skirting the FDA by self-medication; he recently injected himself with a ‘research compound’ that he said could cure herpes. He was planning CRISPR trials in Tijuana.

You’ve heard of Bad Obsession Motorsports, right? It’s a YouTube channel of two blokes in a shed stuffing a Celica into a Mini. It is the greatest fabrication channel on YouTube. They haven’t uploaded anything in six months, but don’t worry: the next episode is coming out on May 18th. Yes, this is newsworthy.

As further evidence that Apple hardware sucks, if you plug both ends of a USB-C PD cable into a MacBook, it charges itself.

Defcon China is this week. Let me set the scene for you. Last year, at the closing ceremonies for Defcon (the Vegas one), [DT] got up on stage and announced 2018 would see the first Defcon in China. The sound of four thousand raised eyebrows erupted. We’re interested to see how this one goes down. Here are the talks It’s a bit light, but then again this is only the first year.

The Swiss Guard is now 3D printing their helmets. The personal army of the Pope also wears funny hats, and they’re replacing their metal helmets with 3D printed ones. Of note: these helmets are printed in PVC. The use of PVC has been repeated in several high-profile publications, leading me to believe that yes, these actually are printed in PVC, or everyone is getting their information from an incorrect Vatican press release This is odd, because PVC will give everyone within a five mile radius cancer if used in a 3D printer, and you wouldn’t use PVC anyway if ABS and PLA are so readily available. If you’re wondering if injection molding makes sense, giving each new recruit their own helmet means producing about thirty per year; the economics probably don’t work.

Morse Code Blinking Jewelry

With the size of electronic parts and batteries these days, very small items are obviously becoming more and more viable. [Yann Guidon] has made some awesome pieces of LED jewelry using a minimal number of surface mount parts and a small lithium-ion battery. To make the jewelry stand out a bit, other than just blinking on and off, these LEDs blink a short message in Morse code.

This is an update and open sourcing of some work that [Yann] did a few years ago, and the iterations have resulted in a smaller design. But the main part of the latest version is the addition of the Morse code blinking using a small microcontroller. The microcontroller [Yann] used is the SMD version of the PIC10F200, a small, 8 pin PIC microcontroller. This, a resistor and a metal clip are soldered to pads on a Luxeon Star LED.  The LEDs are undervolted so they’re not too bright, so the heat sink isn’t really needed, but it’s a good size for the components. Because the LEDs don’t generation much heat, the back of the aluminum frame that the LED is on is carved out a bit so that the small lithium-ion battery can go there.

The final component is the code itself, and [Yann] has released it as an assembly file. An associated text file contains the text of the message that you want the earrings to blink. The text file can contain up to 190 bytes. A shell script converts the text to a file that can be included in the asm file. After that script is run, assemble the code and flash it to the PIC and you’re done!

We’ve seen a couple of other LED jewelry projects done, including this LED engagement ring, and these tiny light-up earrings. You can see video of [Yann]’s project in the video below:
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Hurricane Simulator Buoys Research

They say an ounce of prevention is worth a pound of cure. In this case, 38,000 gallons of seawater is worth an un-quantifiable amount of knowledge about hurricanes. At the University of Miami’s Rosenstiel School of Marine and Atmospheric Science, [Brian Haus] and his colleagues study hurricanes using a simulator–an enclosed glass tank about the size of a lap-swimming pool. With the flip of a switch, a 1700 hp fan can create winds up to 200 miles per hour—stronger than a baseline category 5 hurricane.

Although there’s currently no cure for hurricanes, understanding how they work goes a long way in forecasting their intensity. Scientists know that hurricanes are fueled by the ocean’s warmth, but there’s still plenty of mystery to them. By studying what happens where the wind meets the water, they think they’ll figure out how surface factors like sea spray and bubbles affect a storm’s intensity and drag coefficient. Surf the break to catch the wave tank in action.

Until there’s a cure for hurricanes, we’ll just have to live with them and engineer our structures to withstand them.

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