Today: Hackaday is at UK Maker Faire Plus Afterparty

As a finale to our month on the road through parts of the British Isles, we’ll be at UK Maker Faire this weekend, and we’ll also be hosting our final bring-a-hack at Maker Space Newcastle this evening, Saturday the 28th of April.

For the rest of the weekend’s UK Maker Faire, held at Newcastle’s Life Science Centre, you’ll find both Hackaday and Tindie at our booth number M118, and if you’re lucky you might even snag one of the [Brian Benchoff]-designed Tindie blinkie badge kits.

A few familiar faces from the Brits among our wider community will have their own booths, for example [Spencer] will be there with the RC2014 Z80-based retrocomputer, Rachel “Konichiwakitty” Wong will have her collection of wearables but no 3D-printed eyeballs, and Tindie seller extraordinaire [Partfusion], whose bone conduction skull radio we saw at EMF 2016 (Correction: the bone conduction radio was the work of fellow TOG stalwart [Jeffrey Roe]) and who also spoke at our Dublin Unconference.

There is still time to make your way to Geordieland to attend the event if you haven’t made plans already, and should you bring a conveniently portable hack with you then we’d love to see it. Especially if it’s a Hackaday Prize entry.

An Open Source Sip-and-Puff Mouse for Affordable Accessibility

At the core of any assistive technology is finding a way to do something with whatever abilities the user has available. This can be especially difficult in the case of quadriplegia sufferers, the loss of control of upper and lower limbs caused by spinal cord damage in the cervical region. Quadriplegics can gain some control of their world with a “Sip-and-puff” device, which give the user control via blowing or sucking on a mouthpiece.

A sip-and-puff can make a world of difference to a quadriplegic, but they’re not exactly cheap. So to help out a friend, [Jfieldcap] designed and built an open source sip-and-puff mouse on the cheap. As is best for such devices, the design is simple and robust. The hollow 3D-printed mouthpiece acts as handle for a joystick module , and a length of tubing connects the mouthpiece to a pressure sensor. An Arduino lets the user move his head to position the cursor; hard sips and puffs are interpreted as left and right clicks, while soft mouth pressure is used for scrolling. In conjunction with some of the accessibility tools in modern OSes and personal assistant software like Siri or Cortana, the sip-and-puff opens up the online world, and for all of $50 in material.

We’re impressed by the effort and the results, but we worry that the standard PLA used for the mouthpiece won’t stand up to the cleaning it’ll need. Of course, printing extra mouthpieces is easy, but since it’s going to be in contact with the mouth, perhaps a review of food-safe 3D-printing is in order.

Cams and Pushrods Improve 3D-Printed Compressed Air Engine

Some folks just can’t leave well enough alone, and that often ends up being a good thing. Such is the case with this 3D-printed compressed air engine, which just keeps getting better.

The design has changed a lot since we first covered [Tom Stanton]’s attempts at reviving the powerplant from the glory days of the Air Hogs line of toys, which he subsequently built a plane around. The engine was simple, with a ball valve that admitted air into the cylinder when a spring mounted to the top of the piston popped it out of the way. That spring has always bothered [Tom], though, compelling him to go back to the drawing board. He wanted to replace the ball valve with one actuated by a cam and pushrod. This would increase the complexity of the engine quite a bit, but with the benefit of eliminating the fail point of the spring. With a few iterations in the design, he was able to relocate the ball valve, add a cam to the crankshaft, and use a pushrod to open the valve. The new design works much better than the previous version, sounding more like a lawnmower than a 3D-printed engine should. Check out the design process and some tests in the video below.

And speaking of lawnmowers that run on compressed air

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2018’s Hottest Accessory Is a 3D Printed Air Raid Siren

Some say the spectre of global nuclear annihilation is closer than ever before. What better time to head to the workshop to prepare for the coming apocalypse? [MrExpert] is here with the build you need – an air raid siren you can print at home.

It’s a simple build, which makes it fun and accessible for just about anyone with a 3D printer. Rotational power is provided by a brushless outrunner motor hooked up to an ESC, controlled with a servo tester. The rotor and frame for the parts are 3D printed, and held together with a handful of standard fasteners.

Initial testing proves that yes, it does work and generates a rather earsplitting tone. The second revision improves upon this somewhat. However, the key to getting that authentic sound is in the sweep of the tone. By replacing the servo tester with an Arduino or other micro that can generate smoothly sweeping pulses to ramp the rotational speed up and down, you’ll get much closer to that genuine the-sky-is-falling timbre.

It’s certainly not rocket science, and would make a great project to whip up with the kids on a rainy weekend. While you’re at it you can share the wisdom behind the duck and cover technique, but maybe save the geopolitical rants for when they’re a bit older. We’ve seen air raid siren builds before, too – like this sturdy wooden unit.

Thermoelectric Fan Harvests Wood Stove Heat Junkyard Style

Anyone who heats with a wood stove knows that the experience is completely different from typical central heating. It’s not for everyone, though, and it’s certainly not without its trade-offs. One of the chief complaints is getting heat away from the stove and into other areas of the house, and many owners turn on an electric fan to circulate the heated air.

That’s hardly in the green nature of wood heating, though, and fans can be noisy. So something like this heat-powered stove-top fan can come in handy. Such fans, which use Peltier devices to power a small electric motor, are readily available commercially. [bongodrummer] thought that sounded like no fun, though, and created his own mostly from junk. The Peltier module was salvaged from an old travel fridge and mounted to a heat sink from a computer to harvest heat from the stove. The other side of the Peltier needs to have a heat sink to keep it cooler than the hot side, and [bongodrummer] chose an unconventional bit of salvage for the job — the cylinder of a chainsaw engine. The spark plug hole sprouts the mount for the fan motor, and the cooling fins help keep the Peltier cool. And to prevent overheating of the device, he added a surprise — a car cooling system thermostat to physically lift the device off the stove when it gets too hot. Genius!

The video below shows the build, which was not trivial. But we think the end results are worth it, and it reminds us a little of the woodstove generator we featured a while back.

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Checking The Weather Without A Window

Making a weather display is great because it’s a simple project that shows off some skills and has an obvious daily use. So [ACROBOTIC Industries] decided to make an easy kit for the Hackaday Prize to make weather displays even more accessible.

Calling it the ESPecter, [ACROBOTIC Industries] wanted to make this a simple project for anyone, regardless of skill with a soldering iron or Arduino toolkit. So they decided to base the guts on common components that can be put together easily, specifically a Wemos Mini D1 with an OLED shield as a bright display. They also designed a cool tiltable 3D-printed enclosure for this small device so that you can orient it to your eye level.

ESPecter breadboarded prototype.

While they already have a breadboarded prototype, and a 3D printed case, some software work remains to make the project really shine. They plan to add nice features like a web interface to configure location and network information, alerts, additional locations, and historical weather data. They also want to create a weather library to display well on a low-resolution screen and add battery operation.

We look forward to seeing the final version later in the Hackaday Prize!

This isn’t the first weather project we’ve seen around here. Other variants include mirror weather displays, an ESP8266-based weather monitoring station, a very low-power weather station, and this roundup of weather displays which might give you some inspiration.

A Blockchain, Robotics and AI Event in Vietnam

Blockchain Education Network Vietnam recently held an event titled “Building a Robotics & Artificial Intelligence Ecosystem with Blockchain”. The title alone has three of my favorite things in it, so when a client of mine asked me if I could put together a little hardware demonstration for the event, I jumped at the opportunity.

I also thought I’d take a moment to write about it, because I haven’t seen much coverage of emerging technology events in the developing world, and the fact is that there’s a consistently high level of interest. I’ve yet to go to an event that wasn’t filled to capacity, and I hope to share some of that enthusiasm with you.

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