Open Source Lego Controller

A mechanical and manufacturing engineer by day, [Tyler Collins] taught himself electronics and firmware development in his spare time and created an open source Lego controller called Evlōno One. It is based on the STM32 and Arduino ecosystems, and compatible with a impressive variety of existing Lego controllers, sensors and actuators. [Tyler] encountered Lego Mindstorms while helping in an after-school program, and got to wondering whether he could make a more flexible controller. We’d have to say he succeeded, and it’s amazing how much he has packed into this 4 x 4 single-height brick format.

The Evlōno One is based on an ESP32 dual-core MCU, and has WiFi, Bluetooth, and an IR transmitter for wireless connectivity. It also boasts USB-C power delivery, three motor controllers, speakers, LEDs and a button. Dig through the Kickstarted page for more details on these interfaces and specifications. Both the firmware and the hardware will be published as open source on GitHub.

Although [Tyler] has the prototypes all running, he notes this is his first big production effort. FCC certification testing and production mold tooling are the two biggest items driving the scheduled Feb 2021 shipments. If computer driven Lego modeling is one of your hobbies, definitely check out [Tyler]’s project. And if you missed our [Daniel Pikora]’s FOSSCON 2018 presentation about the intersection (collision) of Legos and Open Source, our article must-read for you folks in the Adult Fan of Lego (AFOL) community.

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Giant Blacksmith Vise From Start To Finish

In any proper workshop you want to be able to securely hold a workpiece, whether it’s a tiny PCB or a heavy piece of forged steel. [Jason Marburger] from Fireball Tool needed a really large heavy-duty vise, so he built himself a massive 1490 lbs / 676 kg floor-standing blacksmith vise from scratch.

Blacksmith vises are designed to take a lot of heavy abuse, such as holding heavy pieces of steel that are being hammered. [Jason]’s vise stands about 3 feet tall, and the main frame components were cut from 1 5/8 inch (41.3 mm) steel with a water jet cutter. The jaws are operated with a large hand wheel connected to a lead screw. Bearings on the lead screw allow the hand wheel to be spun like a flywheel, allowing it to be quickly opened and closed. The weight of the moving jaw keeps the lead screw under tension, eliminating any backlash. This allows for really fine control over the holding force, which [Jason] demonstrates by carefully clamping a tiny screw. With the hand wheel alone the vise can exert 12880 lb / 5800 kg, but a hydraulic lift was also added, boosting the force to 30000 lbs. The deep throat allows a large object to be clamped, and the jaws can also be offset to clamp something to the side of the vise.

The vise was beautifully finished with powder coating and pin striping, which will no doubt wear over time if it’s properly used, but the vise itself should last a few lifetimes. While this isn’t something you can really build in a home workshop, it is always inspiring to see what is possible with a bit more tools, knowledge and skill. The build is documented in a 4 part series (link in first paragraph), but we’ve added a short highlights reel below for your viewing pleasure.

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A Featherweight Direct Drive Extruder In A Class Of Its Own

Even a decade later, homebrew 3D printing still doesn’t stop when it comes to mechanical improvements. These last few months have been especially kind to lightweight direct-drive extruders, and [lorinczroby’s] Orbiter Extruder might just set a paradigm for a new kind of direct drive extruder that’s especially lightweight.

Weighing in at a mere 140 grams, this setup features a 7.5:1 gear reduction that’s capable of pushing filament at speeds up to 200 mm/sec. What’s more, the gear reduction style and Nema 14 motor end up giving it an overall package size that’s smaller than any Nema 17 based extruder. And the resulting prints on the project’s Thingiverse page are clean enough to speak for themselves. Finally, the project is released as open source under a Creative Commons Non-Commercial Share-Alike license for all that (license-respecting!) mischief you’d like to add to it.

This little extruder has only been around since March, but it seems to be getting a good amount of love from a few 3D printer communities. The Voron community has recently reimagined it as the Galileo. Meanwhile, folks with E3D Toolchangers have been also experimenting with an independent Orbiter-based tool head. And the Annex-Engineering crew has just finished a few new extruder designs like the Sherpa and Sherpa-Mini, successors to the Ascender, all of which derive from a Nema 14 motor like the one in the Orbiter. Admittedly, with some similarity between the Annex and Orbiter designs, it’s hard to say who inspired who. Nevertheless, the result may be that we’re getting an early peek into what modern extruders are starting to shape into: smaller steppers and more compact gear reduction for an overall lighter package.

Possibly just as interesting as the design itself is [lorinczroby’s] means of sharing it. The license terms are such you can faithfully replicate the design for yourself, provided that you don’t profit off of it, as well as remix it, provided that you share your remix with the same license. But [lorinczroby] also negotiated an agreement with the AliExpress vendor Blurolls Store where Blurolls sells manufactured versions of the design with some proceeds going back to [lorinczroby].

This is a clever way of sharing a nifty piece of open source hardware. With this sharing model, users don’t need to fuss with fabricating mechanically complex parts themselves; they can just buy them. And buying them acts as a tip to the designer for their hard design work. On top of that, the design is still open, subject to remixing as long as remixers respect the license terms. In a world where mechanical designers in industry might worry about having their IP cloned, this sharing model is a nice alternative way for others to both consume and build off of the original designer’s work while sending a tip back their way.

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AlphaSmart Neo Teardown: This Is The Way To Write Without Distractions

History will always have its in-between technologies — that stuff that tides us over while the Next Big and Lasting Thing is getting the kinks worked out of it. These kinds of devices often do one thing and do it pretty well. Remember zip drives? Yeah you do. Still have mine.

The halcyon days of the AlphaSmart NEO sit in between the time where people were chained to heavy typewriters and word processors and the dawn of on-the-go computing. Early laptops couldn’t be trusted not to die suddenly, but the NEO will run for 700 hours on three AAs.

The NEO stands for the freedom to get your thoughts down wherever, whenever, without the need for a desk, paper, ink, ribbons, power cords, and the other trappings that chain people indoors to flat surfaces. And that’s exactly what was so tantalizing to me about it. Inspiration can truly strike anywhere at any time, so why not be prepared? This thing goes from off to blinking cursor in about a second and a half. There’s even a two-button ‘on’ option so you don’t run the battery down or accidentally erase files while it’s in your bag.

These might be the world’s greatest scissor switches.
L-R: DC power, IR, USB-B, and USB-A for connecting to a printer.

I bought this funny little word processor a few years ago when I wanted to attempt NaNoWriMo — that’s National Novel Writing Month, where you write 50,000 words towards a novel, non-fiction book, or short story collection in any genre you want. It averages out to 1,667 words a day for 30 days. Some days it was easy, some days it was not. But every non-Hackaday word I typed that month was on this, my Mean Green Words Machine.

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Robust Water-Rocket Launcher Gets The Engineering Just Right

Normally when we run across a project that claims to be overengineered, we admit that we get a little excited. Such projects always hold the potential for entertainingly over-the-top designs, materials, and methods. In this case, though, we’ll respectfully disagree with [Zach Hipps] assessment of his remote-controlled soda bottle rocket launcher as “overengineered”. To us, it seems just right.

That’s not to take away from anything accomplished with this build. Indeed, we’re mighty impressed by the completeness of the build, which was intended to create a station for charging and launching air-powered water rockets. The process started with a prototype, built mainly from 3D-printed parts but with a fair selection of workshop scraps to hold it together. This allowed [Zach] to test the geometry of the parts, operation of the mechanism, and how it interfaced with the flange on the necks of 2-liter soda bottles.

Honestly, the prototype was pretty good by itself and is probably where many of us would have stopped, but [Zach] kept going. He turned most of the printed parts into machined aluminum and Delrin, making for a very robust pneumatically operated stand. We’ve got to say the force with which the jaws close around the bottle flange is a bit scary — looks like it could easily clip off a wayward finger. But if he manages to avoid that fate, such a hearty rig should keep [Zach] flying for a long time. Perhaps it could even launch a two-stage water rocket?

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Linux Fu: Monitor Disks

If you want a quick view of a Linux system’s process load, you can use top or — slightly nicer — htop. But what if you want a quick snapshot of how the disk system is doing? There are a few tools you can use, some of which are not nearly as common as top.

First, iotop

Most similar to top is iotop. This program shows you the total and current disk read and write numbers for the file system and also shows you who is eating up the most disk I/O.  This screen looks busy:

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Quadcopter With Tensegrity Shell Takes A Beating And Gets Back Up

Many of us have become familiar with the distinctive sound of multirotor toys, a sound frequently punctuated by sharp sounds of crashes. We’d then have to pick it up and repair any damage before flying fun can resume. This is fine for a toy, but autonomous fliers will need to shake it off and get back to work without human intervention. [Zha et al.] of UC Berkeley’s HiPeRLab have invented a resilient design to do so.

We’ve seen increased durability from flexible frames, but that left the propellers largely exposed. Protective bumpers and cages are not new, either, but this icosahedron (twenty sided) tensegrity structure is far more durable than the norm. Tests verified it can survive impact with a concrete wall at speed of 6.5 meters per second. Tensegrity is a lot of fun to play with, letting us build intuition-defying structures and here tensegrity elements dissipate impact energy, preventing damage to fragile components like propellers and electronics.

But surviving an impact and falling to the ground in one piece is not enough. For independent operation, it needs to be able to get itself back in the air. Fortunately the brains of this quadcopter has been taught the geometry of an icosahedron. Starting from the face it landed on, it can autonomously devise a plan to flip itself upright by applying bursts of power to select propeller motors. Rotating itself face by face, working its way to an upright orientation for takeoff, at which point it is back in business.

We have a long way to go before autonomous drone robots can operate safely and reliably. Right now the easy answer is to fly slowly, but that also drastically cuts into efficiency and effectiveness. Having flying robots that are resilient against flying mistakes at speed, and can also recover from those mistakes, will be very useful in exploration of aerial autonomy.

[IROS 2020 Presentation video (duration 14:16) requires free registration, available until at least Nov. 25th 2020. One-minute summary embedded below]

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