Fail Of The Week: How Not To Build A Filament Extruder

February 28, 2021 by Al Williams 6 Comments

It would be great if you could create your own filament. On the face of it, it seems easy to do, but as [Thomas Sanladerer] found out when he was a student, there are a lot of details that can bedevil your design. His extruder sort of works, but he wouldn’t suggest duplicating his effort. In fact, he hopes you can learn what not to do if you try to do it yourself.

In all fairness, [Thomas] was a low-budget student and was trying to economize. For example, he tried using a drill to drive the auger. Why not? It looks like a drill bit. But he found out that wasn’t satisfactory and moved to a pair of wiper motors with their built-in gear train.

Continue reading “Fail Of The Week: How Not To Build A Filament Extruder” →

Nissan’s Office Pod Concept Is A Productivity Paradise On Wheels

February 28, 2021 by Kristina Panos 40 Comments

All this working from home is pretty great, but we have to admit that we miss packing up the Hackaday office and heading for the local coffeehouse once in a while to spend a few hours writing against the buzzing background. One thing we don’t miss about the experience is that you’re never guaranteed a place to sit and spread out. And unless you trust a friendly stranger to keep an eye on your stuff while you’re in the bathroom, you have to take it with you at the risk of losing your table.

If only we could afford one of Nissan’s mobile office pod concept vehicles. We’ve always wanted to pretend we’re doing surveillance and would probably have the thing wrapped with graphics for a fake flower shop or something. That would certainly make it easier to park somewhere and borrow someone’s open Wi-Fi network — maybe even from the coffeehouse parking lot after we hit the drive-thru.

As you’ll see in the extended tour video below, Nissan seem to have thought of everything except restroom facilities. The cab-over-engine design and all-terrain tires would make it easier to drive out into nature and really get away from it all. Once you’ve found the perfect spot, you can open the lift gate for some fresh air, or get some sun while you work by pulling out the motorized unibody-constructed cubicle which includes a built-in Herman Miller Cosm chair. (Evidently the Aeron is old and busted now; we disagree). For some reason, the cubicle is edge-lit, and not in a way that would help you work at the desk. According to the video, it’s based on the Caravan NV350, which looks far more comfortable but not as cool when outfitted as an alternate mobility concept.

The office pod has some nice amenities like a DC-AC converter so you can run your Keurig or Nespresso, and there’s even a UV-disinfecting lamp in the glove box. The larger windows behind the cab can be electronically shaded so you don’t bake in the sun. Here’s where things get a bit ridiculous: the floor is made of clear polycarbonate in case you want to park lengthwise over a small stream and watch the surviving fish go by underneath your feet. And if you really want to take a break, climb up to the roof deck and stretch out in the chaise lounge beneath the deck umbrella.

If we lived anywhere but America, we might forego the flower shop graphics wrap and dress it up to look like a TV detector van instead.

Continue reading “Nissan’s Office Pod Concept Is A Productivity Paradise On Wheels” →

OnShape To Robot Models Made Easier

February 28, 2021 by Al Williams 7 Comments

We live in a time where our phones have computing power that would have been the envy of NASA a few decades ago. So, in theory, we should be able to simulate just about anything. Thanks to [rhoban], robots you design in OnShape — a popular CAD tool — are now easier to simulate using several common simulation tools.

Electronic circuits are pretty easy to simulate, because we typically draw schematics and circuit simulators can capture those schematics readily. But simulating physics for robotic designs is a bit trickier. Gazebo and Pybullet both can use SDF files or URDF. However, building those files is often a separate process from actual physical design even though you probably did the design using a CAD tool. Even if you don’t use OnShape, you can probably import your preferred format and then bridge to the simulation file format without having to manually recreate your design. You can see the author walk through the process in the video below.

Continue reading “OnShape To Robot Models Made Easier” →

How To Monitor Blood Pressure Without Raising It

February 27, 2021 by Kristina Panos 16 Comments

Does anyone actually enjoy the sensation of being squeezed by a blood pressure cuff? Well, as Mom used to say, it takes all kinds. For those who find the feeling nearly faint-inducing, take heart: researchers at UC San Diego have created a non-invasive medical wearable with a suite of sensors that can measure blood pressure and monitor multiple biochemicals at the same time.

The device is a small, flexible patch that adheres to the skin. So how does it manage to measure blood pressure without causing discomfort? The blood pressure sensor consists of eight customized piezoelectric transducers that bounce ultrasonic waves off the near and far walls of the artery. Then the sensor calculates the time of flight of the resulting echoes to gauge arterial dilation and contraction, which amounts to a blood pressure reading.

This patch also has a chemical sensor that uses a drug called pilocarpine to induce the skin to sweat, and then measures the levels of lactate, caffeine, and alcohol found within. To monitor glucose levels, a mild current stimulates the release of interstitial fluid — the stuff surrounding our cells that’s rife with glucose, salt, fatty acids, and a few minerals. This is how continuous glucose monitoring for diabetes patients works today. You can check out the team’s research paper for more details on the patch and its sensors.

In the future, the engineers are hoping to add even more sensors and develop a wireless version that doesn’t require external power. Either way, it looks much more comfortable and convenient than current methods.

A PCB For A Quarter?

February 27, 2021 by Jenny List 19 Comments

As time has gone by and PCB assembly companies have reached further into the space of affordability for our community, the available types of board have multiplied. No longer are we limited to FR4 with a green solder mask, we can have all colours of the rainbow and a variety of substrates. The folks at BotFactory have taken things a step further with their PCB printer though, by printing a fully-functional PCB on a quarter.

As a base layer the printed five passes of insulation on the coin, before printing the traces. Holes are left in the insulation to create a form of via that connects to the coin. On the board is an ATtiny2313 microcontroller that flashes an LED, and on the reverse side of the coin is a CR2032 cell that’s secured with a set of bolts and washers. You can see it taking shape in the video below the break.

It’s true that an LED flasher isn’t exciting, and that this is a marketing stunt for BotFactory’s printer. But it’s an inventive one, and reminds us that with a bit of ingenuity anything can become a board. We’ve had our share over the years, and instantly springing to mind is this stretchable PCB.

Continue reading “A PCB For A Quarter?” →

Pool Noodle Robot Shines A Light On The Pros And Cons Of Soft Robots

February 27, 2021 by Danie Conradie 4 Comments

[James Bruton]’s impressive portfolio of robots has always used conventional rigid components, so he decided to take a bit of a detour and try his hand at a soft robot. Using a couple of few inflatable pool noodles for quick prototyping, his experiments quickly showed some of the strengths and weaknesses of soft robots.

Most of the soft robots we see require an external air source to inflate cells in the robot and make the limbs actuate. Taking inspiration from a recent Stanford research project, [James] decided to take an alternative approach, using partially inflated tubes and squeezing them in one section to make the other sections more rigid. He bought a couple of cheap pool noodles and experimented with different methods of turning them into actuators. The approach he settled on was a pair of noodles tied together side by side, and then folded in half by an elastic cord. As one end is squeezed by a servo bellows, the internal pressure overcomes the tension from the elastic cord, and the “elbow” straightens out.

[James] tested various arrangements of these limbs to build a working hexapod robot but to no avail. The simple actuating mechanism was simply too heavy, and could just lift itself slightly. This highlighted a common theme in almost all the soft pneumatic robots we’ve seen: they carry very little weight and are always tethered to an external air supply. The combination of stretchy materials and relatively low pressure compressed air can only handle small loads, at least in Earth gravity and above water. Continue reading “Pool Noodle Robot Shines A Light On The Pros And Cons Of Soft Robots” →

Circle Full Of LEDs Becomes A Clock

February 27, 2021 by Rich Hawkes 5 Comments

Building a clock of some sorts seems to be a time honored tradition for hackers and LED clocks seem one of the most popular. You can build anything from a seven-segment display to a binary clock or something even more fancy. [Clueless] found a circle of LED rings online and with made an LED version of an analog clock.

Continue reading “Circle Full Of LEDs Becomes A Clock” →