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 …read more

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Auto-Tracking Sentry Gun Gives Deer a Super Soaking

Things rarely go well when humans mix with wildlife. The problems are exacerbated in the suburbs, where bears dine on bird feeders and garbage cans, raccoons take up residence in attics, and coyotes make off with the family cat. And in the suburbs, nuisance wildlife can be an intractable problem because the options for dealing with it are so limited.

Not to be dissuaded in the battle to protect his roses, [dlf.myyta] built this motion-activated sentry gun to apply some watery aversion therapy to marauding deer. Shown in action below against a bipedal co-conspirator, the sentry gun has pretty much …read more

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The Miracle of Injection Molding: How Does it Work?

Pretty much any household item nowadays has an involved, extremely well-thought-out manufacturing method to it, whether it’s a sheet of paper, an electrical outlet, a can of tuna, or even the house itself. Some of the stories of how these objects came to be are compelling, though, as one of the recent videos from [This Old Tony] shows as he takes a deep dive into a $5 ball valve, and uses it to talk about all of the cool things you can do with injection molding.

Injection molding is the process of casting molten plastic into more useful pieces of …read more

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Automated Chamber Passes Just the Right Gas

It sounds like an overly complicated method a supervillain would use to slowly and painfully eliminate enemies — a chamber with variable oxygen concentration. This automated environmental chamber isn’t for torturing suave MI6 agents, though; rather, it enables cancer research more-or-less on the cheap.

Tasked with building something to let his lab simulate the variable oxygen microenvironments found in some kinds of tumors, [RyanM415] first chose a standard lab incubator as a chamber to mix room air with bottled nitrogen. With a requirement to quickly vary the oxygen concentration from the normal 21% down to zero, he found that the …read more

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Spray Paint Goes DIY Virtual with a Vive Tracker

Here is a virtual spray painting project with a new and DIY twist to it. [Adam Amaral]’s project is an experiment in using the Vive Tracker, which was released earlier this year. [Adam] demonstrates how to interface some simple hardware and 3D printed parts to the Tracker’s GPIO pins, using it as a custom peripheral that is fully tracked and interactive in the Vive’s VR environment. He details not only the custom spray can controller, but also how to handle the device on the software side in the Unreal engine. The 3D printed “spray can controller” even rattles when shaken! …read more

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Superconference Interview: Alan Yates

In 2015, virtual reality was the future, which means we should all have it right now. One of the most technologically impressive VR sets is the HTC Vive, an amazing piece of kit that’s jam-packed with sensors and has some really cool tech going on inside it.

One of the developers of the HTC Vive and the ever-important ‘Lighthouse’ position sensors is [Alan Yates]. He’s of Valve and gave a talk at last year’s Superconference on Why the Lighthouse Can’t Work. Being able to determine the absolute position of the Valve’s headset is hard, but absolutely necessary for VR. Anything …read more

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Classic IBM TR-2 Flip-Flop Reproduction

As useful as computers are, most of them have all the design charm of a rubber doorstop. Oh, for the heady early days of computing, when vacuum tubes ruled, hardware was assembled by hand, and engineers always wore a tie.

Looking to recreate an elegant bit of computing hardware from that more civilized age, [updatebjarni] built a reproduction of a 1948 IBM TR-2 flip-flop module — 1,250 of which once formed the memory of the IBM Model 604 Calculating Punch. Admittedly more of a high-speed adding machine than a computer, the 604 is still an important piece of computing history, …read more

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