The Prusa I3 MK3S And A Tale Of Two Sensors

October 8, 2020 by Tom Nardi 78 Comments

When the Prusa i3 MK3 was released in 2017, it was marketed as being “bloody smart” thanks to the impressive number of sensors that had been packed into the printer. The update wasn’t really about improving print quality over the MK2, but rather to make the machine easier to use and more reliable. There was a system for resuming prints that had stopped during a power outage, a thermometer so the firmware could compensate against thermal drift in the inductive bed sensor, RPM detection on all of the cooling fans, and advanced Trinamic stepper drivers that could detect when the printer had slipped or gotten stuck.

The optical filament sensor of the Prusa i3 MK3.

But the most exciting upgrade of all was the new filament sensor. Using an optical encoder similar to what you’d find in a mouse, the Prusa i3 MK3 could detect when filament had been inserted into the extruder. This allowed the firmware to pause the print if the filament had run out, a feature that before this point was largely unheard of on consumer-grade desktop 3D printers. More than that, the optical encoder could also detect whether or not the filament was actually moving through the extruder.

In theory, this meant the MK3 could sense problems such as a jammed extruder or a tangle in the filament path that was keeping the spool from unrolling. Any other consumer 3D printer on the market would simply continue merrily along, not realizing that it wasn’t actually extruding any plastic. But the MK3 would be able to see that the filament had stalled and alert the user. The capabilities of the optical filament sensor represented a minor revolution in desktop 3D printing, and combined with the rest of the instrumentation in the MK3, promised to all but eradicate the heartbreak of failed prints.

Fast forward to February of 2019, and the announcement of the Prusa i3 MK3S. This relatively minor refresh of the printer collected up all the incremental tweaks that had been made during the production of the MK3, and didn’t really add any new features. Though it did delete one: the MK3S removed the optical encoder sensor used in the MK3, and with it the ability to sense filament movement. Users would have to decide if keeping the ability to detect clogs and tangles was worth giving up all of the other improvements offered by the update.

But why? What happened in those three years that made Prusa Research decide to abandon what promised to be a huge usability improvement for their flagship product? The answer is an interesting look at how even the cleverest of engineering solutions don’t always work as expected in the real-world.

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Typhoon-Tough Turbines Withstand Wild Winds

October 7, 2020 by Kristina Panos 25 Comments

It’s really beginning to feel as though the problem of climate change is a huge boulder rolling down a steep hill, and we have the Sisyphean task of trying to reverse it. While we definitely need to switch as much of the planet over to clean, green energy as soon as possible, the deployment should be strategic. You know, solar panels in sunny places, and wind turbines in windy places. And for the most part, we’re already doing that.

A test unit in Okinawa, Japan. Image via Challenergy

In the meantime, there are also natural disasters to deal with, some of which are worsened by climate change. Eastern and Southeast Asian countries are frequently under the threat of typhoons that bring strong, turbulent winds with them. Once the storms pass, they leave large swaths of lengthy power outages in their wake.

Studies have shown that these storms are gaining strength over the years, leading to more frequent disruption of existing power systems in those areas. Wind power is the ideal solution where storms have come through and knocked out traditional power delivery all over a region. As long as the turbines themselves can stand up to the challenge, they can be used to power micro-grids when other delivery is knocked out.

Bring On the Typhoons?

Unfortunately, the conventional three-bladed wind turbines you see dotting the plains can’t stand up to the awesome power of typhoons. But vertical axis wind turbines can. Though they have been around for many years, they may have finally found their niche.

A Japanese startup called Challenergy wants to face the challenge of typhoons head on. They’ve built a vertical axis wind turbine that’s built to not only to withstand typhoon-level winds, it’s designed to make the most of them. Instead of horizontally-situated blades arranged like spokes or flower petals, these turbines have vertical cylinders that collect wind by harnessing the Magnus effect.

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Welcome To Solar Cycle 25; Our Sun Enters A New 11-Year Period

October 6, 2020 by Dan Maloney 45 Comments

Most of us perceive time as an arrow, a one-way trip into the future. And while that’s true, nature has a way of interpolating circular patterns onto that linear model — day follows night, the seasons progress through the year, and generations are born, live, and die after creating the next generation to do experience the same cycles in the future.

Our star, too, follows this cyclical model, and goes through observable, periodic changes that are of keen interest to solar scientists. So it was with some fanfare that they recently announced that the sun had transitioned into Solar Cycle 25. But what exactly does that mean? Does the Sun’s changing face make much difference to the average person’s daily life? History shows that it can, so it pays to know what we’re in store for over the next couple of decades. Welcome to your primer on Solar Cycle 25.

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Tesla’s New Tabless Batteries Unlock New Levels Of Performance

October 5, 2020 by Zoe Skyforest 104 Comments

Telsa are one of the world’s biggest purchasers of batteries through their partnerships with manufacturers like Panasonic, LG and CATL. Their endless hunger for more cells is unlikely to be satiated anytime soon, as demand for electric cars and power storage continues to rise.

As announced at their Battery Day keynote, Tesla has been working hard on a broad spectrum of projects to take battery technology to the next level in order to reach their goal of 3 TWh annual production by 2030. One of the most interesting aspects of this was the announcement of Tesla’s new tabless 4680 battery, which will be manufactured by the company itself. Let’s take a look at what makes the 4680 so exciting, and why going tabless is such a big deal. Continue reading “Tesla’s New Tabless Batteries Unlock New Levels Of Performance” →

NVIDIA Announces $59 Jetson Nano 2GB, A Single Board Computer With Makers In Mind

October 5, 2020 by Tom Nardi 47 Comments

NVIDIA kicked off their line of GPU-accelerated single board computers back in 2014 with the Jetson TK1, a $200 USD development system for those looking to get involved with the burgeoning world of so-called “edge computing”. It was designed to put high performance computing in a small and energy efficient enough package that it could be integrated directly into products, rather than connecting to a data center half-way across the world.

The TK1 was an impressive piece of hardware, but not something the hacker and maker community was necessarily interested in. For one thing, it was fairly expensive. But perhaps more importantly, it was clearly geared more towards industry types than consumers. We did see the occasional project using the TK1 and the subsequent TX1 and TX2 boards, but they were few and far between.

Then came the Jetson Nano. Its 128 core Maxwell CPU still packed plenty of power and was fully compatible with NVIDIA’s CUDA architecture, but its smaller size and $99 price tag made it far more attractive for hobbyists. According to the company’s own figures, the number of active Jetson developers has more than tripled since the Nano’s introduction in March of 2019. With the platform accessible to a larger and more diverse group of users, new and innovative applications for machine learning started pouring in.

Cutting the price of the entry level Jetson hardware in half was clearly a step in the right direction, but NVIDIA wanted to bring even more developers into the fray. So why not see if lightning can strike twice? Today they’ve officially announced that the new Jetson Nano 2GB will go on sale later this month for just $59. Let’s take a close look at this new iteration of the Nano to see what’s changed (and what hasn’t) from last year’s model.

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Certifying Nuclear Reactors: How The NRC Approved Its First Small Modular Reactor Design

October 1, 2020 by Maya Posch 38 Comments

The US Nuclear Regulatory Commission (NRC) recently announced that it had approved certification of NuScale’s SMR (small modular reactor) design, completing its Phase 6 review of NuScale’s Design Certification Application (DCA). What this means is that SMRs using NuScale’s reactor design can legally be constructed within the US as soon as the rulemaking process completes. An NRC certification would also mean that certification of the design in other countries should pose no significant hurdles.

A question that remains unanswered at this point for most is how this certification process at the NRC actually works. Are there departments full of engineers at the NRC who have been twiddling their thumbs for the past decades while the US nuclear industry has been languishing? What was in the literally millions of documents that NuScale had to send to the NRC as part of the certification process, and what exactly are these six phases?

Stay tuned for a crash course in nuclear reactor certification, after a bit of SMR history.

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Choosing The Right RTC For Your Project

September 30, 2020 by Zoe Skyforest 27 Comments

When it comes to measuring time on microcontrollers, there’s plenty of ways to go about things. For most quick and dirty purposes, such as debounce delays or other wait states, merely counting away a few cycles of the main clock will serve the purpose. Accurate to the tens of milliseconds, they get the average utility jobs done without too much fuss.

However, many projects are far more exacting in their requirements. When you’re building a clock, or a datalogger, or anything that relies on a stable sense of passing time for more than a few minutes, you’ll want a Real Time Clock. So called due to their nature of dealing with real time, as we humans tend to conceive it, these devices take it upon themselves to provide timekeeping services with a high degree of accuracy. We’ve compiled a guide to common parts and their potential applications so you can get things right the first time, every time.

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