A Modular System For Building Heavy Duty 18650 Battery Packs

December 13, 2019 by Tom Nardi 42 Comments

With 18650 cells as cheap and plentiful as they are, you’d think building your own custom battery packs would be simple. Unfortunately, soldering the cells is tricky, and not everyone is willing to invest in a spot welding setup just to put the tabs on them. Of course that’s only half the battle, you’ll still want some battery protection and management onboard to protect the cells.

The lack of a good open source system for pulling all this together is why [Timothy Economu] created DKblock. Developed over the last three years, his open source system allows users to assemble large 18650 battery packs for electric vehicles or home energy storage, complete with integrated intelligent management and protection systems. Perhaps best of all there’s no welding required, the packs simply get bolted together.

Each block of batteries is assembled using screws and standoffs in conjunction with ABS plastic cell holders. A PCB is placed on each side of the stack, and with tabs not unlike what you’d see in a traditional battery compartment, all the cells get connected without having to solder or weld anything to them. This allows for the rapid assembly of battery packs from 7.2 VDC all the way up to 150 VDC , and means individual cells can easily be checked and replaced in the future should the need arise.

For monitoring the cells, a “Block Manager” board is installed on each block, which communicates wirelessly to a “Pack Supervisor” board that monitors the overall health of the system. Obviously, such a robust system is probably a bit overkill if you’re just looking to build a pack for your quadcopter, but if you’re looking to build a DIY Powerwall or juice up a custom electric vehicle, this could be the battery management system you’ve been looking for.

An Open Source Toolbox For Studying The Earth

November 13, 2019 by Tom Nardi 1 Comment

Fully understanding the planet’s complex ecosystem takes data, and lots of it. Unfortunately, the ability to collect detailed environmental data on a large scale with any sort of accuracy has traditionally been something that only the government or well-funded institutions have been capable of. Building and deploying the sensors necessary to cover large areas or remote locations simply wasn’t something the individual could realistically do.

But by leveraging modular hardware and open source software, the FieldKit from [Conservify] hopes to even the scales a bit. With an array of standardized sensors and easy to use software tools for collating and visualizing collected data, the project aims to empower independent environmental monitoring systems that can scale from a handful of nodes up to several hundred.

We’ve all seen more than enough DIY environmental monitoring projects to know there’s nothing particularly new or exciting about stuffing a few cheap sensors into a plastic container. But putting high quality, reliable hardware into large scale production is another thing entirely. Especially when your target user may have limited technical knowledge.

That’s why FieldKit is designed around a common backplane with modular sensors and add-on boards that can be plugged in and easily configured with a smartphone application. Whether the node is going to be mounted to a pole and powered by a solar panel, or attached to a buoy, most of the hardware stays the same.

While the electronics and the software interface are naturally the stars of the show here, we can’t help but also be impressed with the enclosure for the FieldKit. It seems a minor thing, but as we’ve seen from the projects that have come our way over the years, finding a box to put your hardware in that’s affordable, adaptable, and weatherproof is often a considerable challenge in itself. Rather than using something commercially available, [Conservify] has designed their own enclosure that’s inspired by the heavy duty (but prohibitively expensive) cases from Pelican. It features a replaceable panel on one side where the user can pop whatever holes will be necessary to wire up their particular project without compromising the case itself; just get a new panel when you want to reconfigure the FieldKit for some other task. Prototypes have already been 3D printed, and the team will be moving to injection molded versions in the near future.

As a finalist in the 2019 Hackaday Prize, FieldKit exemplifies everything we’re looking for this year: a clear forward progression from prototype to final hardware, an obvious need for mass production, and the documentation necessary to show why this project is deserving of the $125,000 grand prize up for grabs.

Continue reading “An Open Source Toolbox For Studying The Earth” →

Robot Joints Go Modular With This Actuator Project

October 22, 2019 by Donald Papp 4 Comments

[John Lauer] has been hard at work re-thinking robot arms. His project to create modular, open source actuators that can be connected to one another to form an arm is inspiring, and boasts an impressively low parts cost as well. The actuators are each self-contained, with an ESP32 and a design that takes advantage of the form factors of inexpensive modules and parts from vendors like Aliexpress.

Flex spline in action, for reducing backlash

Each module has 3D printed gears (with an anti-backlash flex spline), an RGB LED for feedback, integrated homing, active cooling, a slip ring made from copper tape, and a touch sensor dial on the back for jogging and training input. The result is a low backlash, low cost actuator that keeps external wiring to an absolute minimum.

Originally inspired by a design named WE-R2.4, [John] has added his own twist in numerous ways, which are best summarized in the video embedded below. That video is number three in a series, and covers the most interesting developments and design changes while giving an excellent overview of the parts and operation (the video for part one is a basic overview and part two shows the prototyping process, during which [John] 3D printed the structural parts and gears and mills out a custom PCB.)

Continue reading “Robot Joints Go Modular With This Actuator Project” →

A Modular Ecosystem That Evolved Around A Simple Diesel Engine

October 6, 2019 by Roger Cheng 20 Comments

High volume commodity products are a foundation of hacking, we’ve built many projects around popular form factors like NEMA 17 stepper motors, 608 bearings, and 280 DC motors. Their high volume led to lower cost, which further increased popularity, and the cycle repeats. A similar thing happened to a style of single-cylinder diesel engine in China, and [Jalopnik] takes us through an exploration of these “Tuo La Ji” (tractor) machines.

Like many popular standards, circumstances elevated this style of engine to become more popular than its peers. Judging from the pictures, the idea is similar to NEMA 17 in that the core essence is a bolt pattern and an output shaft. Different manufacturers offer various capabilities within this space, and a wild assortment of machinery evolved to take advantage of this class of power source.

It starts with a set of wheels and handlebars to create a walk-behind farm tractor, something pretty common around the world. But this particular ecosystem grew far beyond that to many other applications, including full sized trucks with off-road capability that would embarrass most of the genteel SUVs cruising our roads today. They may not be fast, but they only needed to be faster and have longer endurance than beasts of burden to be effective as “a horseless horse”.

Due to factors such as poor crash safety, absence of diesel emission controls, and affordability of more powerful (and faster!) vehicles, these machines are a dying breed. But that won’t change the fact there was a fantastic amount of mechanical hacking ingenuity that had sprung up around this versatile engine building simple and effective machines. Their creativity drew from the same well that fed into these Indonesian Vespas.

Photo by [Brian Holsclaw] CC BY-ND 2.0

The Thrill Of Building Space Hardware To Exceptionally High Standards

February 4, 2019 by Tom Nardi 10 Comments

It’s fair to say that the majority of Hackaday readers have not built any hardware that’s slipped the surly bonds of Earth and ventured out into space proper. Sure we might see the occasional high altitude balloon go up under the control of some particularly enterprising hackers, but that’s still a far cry from a window seat on the International Space Station. Granted the rapid commercialization of space has certainly added to that exclusive group of space engineers over the last decade or so, but something tells us it’s still going to be quite some time before we’re running space-themed hacks with the regularity of Arduino projects.

That being the case, you might assume the protocols and methods used to develop a scientific payload for the ISS must seem like Latin to us lowly hackers. Surely any hardware that could potentially endanger an orbiting outpost worth 100+ billion dollars, to say nothing of the human lives aboard it, would utilize technologies we can hardly dream of. It’s probably an alphabet soup of unfamiliar acronyms up there. After all, this is rocket science, right?

There’s certainly an element of truth in there someplace, as hardware that gets installed on the Space Station is obviously held to exceptionally high standards. But Brad Luyster is here to tell you that not everything up there is so far removed from our Earthly engineering. In fact, while watching his 2018 Hackaday Superconference talk “Communication, Architecture, and Building Complex Systems for SPAAACE”, you might be surprised just how familiar it all sounds. Detailing some of the engineering that went into developing the Multi-use Variable-G Platform (MVP), the only centrifuge that’s able to expose samples to gravitational forces between 0 and 1 g, his talk goes over the design considerations that go into a piece of hardware for which failure isn’t an option; and how these lessons can help us with our somewhat less critically important projects down here.

Check out Brad’s newly published talk video below, and then join me after the break for a look at the challenges of designing hardware that will live in space.

Continue reading “The Thrill Of Building Space Hardware To Exceptionally High Standards” →

Open Source Synthesizers Hack Chat

January 21, 2019 by Dan Maloney 2 Comments

Matt Bradshaw is a musician, maker, and programmer with a degree in physics and a love for making new musical instruments. You may remember his PolyMod modular digital synthesizer from the 2018 Hackaday Prize, where it made the semifinals of the Musical Instrument Challenge. PolyMod is a customizable, modular synthesizer that uses digital rather than analog circuitry. That seemingly simple change results in a powerful ability to create polyphonic patches, something that traditional analog modular synths have a hard time with.

Please join us for this Hack Chat, in which we’ll cover:

The hardware behind the PolyMod, and the design decisions that led Matt to an all-digital synth
The pros and cons of making music digitally
Where the PolyMod has gone since winning the Musical Instrument Challenge semifinals

You are, of course, encouraged to add your own questions to the discussion. You can do that by leaving a comment on the Open Source Synthesizers Hack Chat and we’ll put that in the queue for the Hack Chat.

Our Hack Chats are live community events on the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, January 23, at noon, Pacific time. If time zones got you down, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io.

You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about. And don’t forget to check out the Modular Synth Discussion, a very active chat that digs into the guts of all sorts of modular synthesizers.

Modular Violin Takes A Bow

October 16, 2018 by Bryan Cockfield 10 Comments

They say the only difference between a violin and a fiddle is the way you play it. If that’s so, this modular violin will need a new name, since it can be broken apart and changed in ways that make it sound completely different, all within a few minutes.

The fiddle is the work of [David Perry] and has 3D printed body, neck, pegbox, and bridge. While it might seem useful on the surface as a way to get less expensive instruments out in the world where virtually anyone has access to them, the real interesting qualities are shown when [David] starts playing all of the different versions he’s created. The sound changes in noticeable ways depending on the style of print, type of plastic used, and many other qualities.

Of course you will need a bow, strings, pegs, and a fingerboard, but the rest is all available if you have a 3D printer around. If you’re already a skilled violinist this could be a very affordable way to experiment with new sounds. It’s not the first time we’ve seen 3D printed violins, but it is the first time we’ve seen them designed specifically to alter the way they sound rather than their physical characteristics. If you want to make your own, all of the .stl files are available on the project’s site.

Continue reading “Modular Violin Takes A Bow” →