Making Custom 3D Printed Slide Switches

January 8, 2020 by Tom Nardi 13 Comments

For a little over a year now we’ve been covering the incredible replicas [Mike Gardi] has been building of educational “computers” from the very dawn of the digital age. These fascinating toys, many of which are now extremely rare, are recreated using 3D printing and other modern techniques for a whole new generation to enjoy and learn from.

He’s picked up a trick or two building these replicas, such as this method for creating bespoke slide switches with a 3D printer. Not only does this idea allow you to control a custom number of devices, but as evidenced in the video after the break, the printed slider sounds absolutely phenomenal in action. Precisely the sort of “clunk” you want on your front panel.

Of course, [Mike] doesn’t expect anyone to create this exact switch. He’s designed it as part of his Working Digital Computer (WDC-1) project that he’s documenting on Hackaday.io, so it has a rather specific set of design parameters. But with the steps he outlines in the write-up, you should have no problem adapting the concept to fit your specific needs.

So how does it work? One half of the switch is a track is printed with indents for both reed switches and 6 x 3 mm disc magnets. The other is a small shuttle that itself has spaces for two of the same magnets. When it slides over the reed switches they’re activated by the magnet on one side, while the magnet on the other side will be attracted to the one embedded into the track. This not only gives the switch detents that you can feel and hear while moving it, but keeps the shuttle from sliding off the intended reed switch.

If you like this, you’ll absolutely love his mostly 3D printed binary encoder that we featured recently. With his track record, we’re excited to follow the WDC-1 project as it develops, and thrilled that [Mike] has brought it to Hackaday.io.

Continue reading “Making Custom 3D Printed Slide Switches” →

New Part Day: Sonoff USB Smart Adaptor Taps A New WiFi Chip

December 26, 2019 by Tom Nardi 49 Comments

For decades, we dreamt of a future where all of our electronics used a standardized power connector. Most of us probably didn’t expect that USB would ultimately fill that role, but we’ll take what we can get if it means a future without getting a new wall wart for every piece of tech we buy. From soldering irons to laptops, the number of things you can power with a lowly USB cable these days is pretty incredible.

Which makes it all the more surprising it took so long for somebody to come up with a way to toggle USB devices off and on over the network. The Sonoff “USB Smart Adaptor”, which the company says will start shipping before the end of the year, is the logical evolution of their exceptionally popular mains voltage smart switches. The Smart Adapter is designed to go between the device and its existing power supply, allowing the user to drag any USB powered device kicking and screaming into their existing smart home setup. All for the princely sum of $6.50 USD.

In the video after the break, Sonoff gives a few potential uses of the Smart Adapter: from controlling a string of LEDs to limiting how long a smartphone is allowed to charge for. But really, there’s a nearly limitless number of devices which could be easily and cheaply integrated into your home automation routines thanks to this gadget.

On the other end of the spectrum, those who are looking to keep a tighter control on the ears and eyes that are active in their home could use the Smart Adapter to make sure their Google and Amazon ~~listening devices~~ assistants are only powered up during certain hours of the day.

Unfortunately, there’s a catch. Sonoff smart switches are best known, at least among the type of folks who read Hackaday, for the fact that they’re based on the eminently hackable ESP8266 microcontroller. Given the size of this product and its intended use, it would seem logical enough to assume this device also utilizes the insanely popular chip. But according to a Sonoff representative, the USB Smart Adapter won’t be using an ESP at all; leaving its hackability an open question until people can actually get their hands on them and start poking around.

Continue reading “New Part Day: Sonoff USB Smart Adaptor Taps A New WiFi Chip” →

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.

Making Your Own Chain Sprockets, The Tidy Way

November 29, 2019 by Lewin Day 17 Comments

Chain sprockets are a key drivetrain component in a lot of builds. Unfortunately they can be difficult to source, particularly for those outside the reach of retailers like McMaster-Carr. In such situations, you might consider making your own.

The toothed profile on a chain sprocket can be produced in a simple manner by drawing a base circle, along with a series of circles spaced appropriately for the chain in question. This involves measuring the pitch and roller diameter of the chain. With these measurements in hand, a template can be created to produce the sprocket.

From there a series of holes are drilled to rough out the basic shape of the teeth, before the sprocket is then cut down to its appropriate outer diameter. The finishing work consists of chamfering the sprocket’s thickness, as well as the filing the sharp edges of the teeth for smooth engagement.

It’s a quick and easy method for producing sprockets with well-defined, accurate profiles. We’ve featured other rough and ready methods before, too. Video after the break.

Continue reading “Making Your Own Chain Sprockets, The Tidy Way” →

New Part Day: The Bizen Transistor

November 23, 2019 by Jenny List 64 Comments

If we had a dollar for every exciting new device that’s promised to change everything but we never hear of beyond the initial hoopla, we’d own our own private islands in the sun from the beaches of which we’d pick out Hackaday stories with diamond-encrusted keyboards. The electronic engineering press likes to talk about new developments, and research scientists like a bit of publicity to help them win their next grant.

The Bizen transistor however sounds as though it might have some promise. It’s a novel device which resembles a bipolar transistor in which the junctions exhibit Zener diode-like properties, and in which the mechanism is through quantum tunneling rather than more conventional means. If this wasn’t enough, its construction is significantly simpler than conventional semiconductors, requiring many fewer support components to make a logic gate than traditional CMOS or TTL, and requires only eight mask steps to manufacture. This means that lead times are slashed, and that the cost of producing devices is much reduced.

The device’s originator has partnered with a semiconductor fab house to offer a service in which custom logic chips can be produced using the new devices in a series of standard building blocks. This is likely to be only of academic interest to the hacker at the moment, however the prospect of this cost reducing as the technology matures does show promise of reaching the means of some more well-funded hacker projects. It will be a while before we can order a chip with the same ease as a PCB, but this makes that prospect seem just a little bit closer.

Thanks [Ken Boak] for the tip.

Diode Basics By [W2AEW]

November 11, 2019 by Al Williams 8 Comments

We didn’t think we needed a basic guide to diodes until we saw it was from [W2AEW], and then we knew we’d pick up some new things. Entitled “Diodes from Ideal to Real” the 18-minute video doesn’t disappoint with a mix of notes and time with a curve tracer to learn all about these devices.

As is typical for a [W2AEW] video this doesn’t just cover the simple operation of diode. It includes topics such as dynamic resistance, junction capacitance, and talks about a wide variety of diode types.

Continue reading “Diode Basics By [W2AEW]” →

A Dancing Cowboy Nixie Tube

October 27, 2019 by Jenny List 10 Comments

If there were four words you never expected to hear in sequence, they would probably be “Dancing cowboy Nixie tube”. But that’s just what [Glasslinger] has made, and it’s exactly what it sounds like – an encapsulated cowboy that dances.

We’ve placed the resulting video below the break, and in it we see a compelling tour through the construction of a Nixie, and the specialist tools required. Little touches such as the need to insulate with glass capillary tube whose wires which shouldn’t glow, the construction of the envelope and stem, and the painstaking layout of the various cowboy components on a sheet of mica are carefully explained.

The tube takes shape in front of us, a driver PCB is etched, and the whole arrangement is placed in a custom wooden box. This is old-school construction at its finest, with the only touch of modernity coming from an Arduino Uno that schedules the various segments. It’s not beyond imagination though to see in time gone by that a Honeywell mechanical sequencer might have been used for the same task.

We’ve brought you [Glasslinger]’s work before of course, but we’ve also seen some more conventional self-made Nixies.

Continue reading “A Dancing Cowboy Nixie Tube” →