Giant Working NERF Gun Runs On Tiny Arduino

October 1, 2021 by Kristina Panos 8 Comments

Well, here it is: a shoe-in for the new world’s largest NERF gun. (Video, embedded below.) The Guinness people haven’t shown up yet to award [Michael Pick], but at 12.5 feet, this baby is over twice as long as the current record holder, which belongs to former NASA mechanical engineer Mark Rober and his now-puny six-foot six-shooter.

We have to wonder if it is technically bigger than the six-shooter, because they seem to be roughly the same scale, except that [Michael] chose a much bigger model to start from. The main body is made from wood, and there are a ton of 3D-printed details that make it look fantastically accurate. The whole thing weighs over 200 pounds and takes at least two people to move it around. We especially love the DIY darts that [Michael] came up with, which are made from a PVC tube inside a section of pool noodle, topped off with a 3D printed piece for that distinctive orange cap.

Propelling those darts at around 50 MPH is a 3,000 PSI air tank connected to an Arduino Pro Mini that controls the trigger and the air valves. While [Michael] hasn’t run the thing quite that high, it does plenty of damage in the neighborhood of 40-80 PSI. As you’ll see in the video after the break, this is quite the ranged weapon. Watch it blow a hole clean through a sheet of drywall and much more.

Want to build something with a bit more stealth? Make it death from above with a NERF quadcopter.

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Expanding On The Creation Of Collapsible Containers

September 30, 2021 by Kristina Panos No comments

You might remember that industrial designer [Eric Strebel] tried to make a collapsible silicone container with 3D printed molds a few weeks ago, and was finally successful after dozens of attempts. Someone commented that commercial containers are molded in the collapsed position instead of the expanded position, so naturally, [Eric] had to try it once he saw the photographic proof of these molds.

This time around, [Eric] made things easier on himself by adding some handles to the mold and using both wax and spray mold release before pouring in the degassed silicone. The first one was a failure — he had let it cure the whole time in the collapsed mold, and it just didn’t want to stay expanded. On the second attempt, [Eric] decided to pull the piece while it was curing, about 5 1/2 hours into the process.

After carefully de-molding the piece, he pressed it into the grooves of one of the older molds from the days of molding containers in the expanded state. Then he filled it with sand and let it cure the rest of the way. That worked out quite well, but even so, [Eric] made a third attempt that he pulled after 3.5 hours or so when the silicone was still sticky. He did the sand trick again, but this time, he ran a piece of string up the wall and over the edge so that the air that gets trapped under the sand can escape. The final result looks great, albeit a little bit floppy, but [Eric] fits the final product into a frame that makes them much sturdier. Check out the process in the video after the break.

Did you miss the first installment? It’s worth a look into the science of creating collapsible walls.

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Left: kids stomping spiders projected on a driveway. Right: the setup.

Make This Halloween A Spider-Stomping Good Time

September 30, 2021 by Kristina Panos 11 Comments

We can count on one hand the number of times that we haven’t needed a coat on Halloween night around here. Even if it was fair and sunny the day before, you can count on Halloween being appropriately windy, cold, and spooky. Trick-or-treating only keeps a kid so warm, and we would have loved to happen upon a house with a spider-stomping sugar-burning good time of a game going on in the driveway.

[Kyle Maas] built this game a few years ago, and it has proved quite popular ever since. It’s so popular, in fact, that they have to have someone on duty with a vaudeville hook to yank spectators off the playing field. The point is to stomp as many spiders as you can in a set amount of time, though you only need to stomp one to win. It can handle one to four players, depending on the size of the projection, but [Kyle] says it’s kind of hard to track more than two at a time.

The setup is fairly simple, provided you can reliably affix your projector to something sturdy. [Kyle] used a Structure sensor for the 3D scanner, but you could easily use a Kinect instead. Conversely, the calibration was challenging. [Kyle] ended up using a DSP math trick known as the inverse bilinear transform to be able to calibrate the system using the 3D scanner itself.

If you’re more into scaring the children, just rig up a coffin bell. Either way, don’t forget about our Halloween Hackfest contest, running now through Monday, October 11th. There are more details over on IO. While you’re there, why not check out the list of entries?

A conventiongoer plays Pokemon on a working Color Game Boy costume.

Convention Plays Pokemon On Giant Color Game Boy Costume

September 29, 2021 by Kristina Panos 2 Comments

Standard cosplay is fun and all, but what is there for admirers to do but look you up and down and nitpick the details? Interactive cosplay, now that’s where it’s at. [Jaryd Giesen] knows this, and managed to pull together a working color Game Boy costume in a few days.

The original plan was to use a small projector on an arm, like one of those worm lights that helped you see the screen, but [Jaryd] ended up getting a secondhand monitor and strapping it to his chest. Then he took the rest of the build from there. Things are pretty simple underneath all that cardboard: there’s a Raspberry Pi running the RetroPie emulator, a Pico to handle the inputs, and two batteries — one beefy 12,000 mAH battery for the monitor, and a regular power pack for the Pi and the Pico.

As you’ll see in the build and demo video after the break, nearly 100 people stopped to push [Jaryd]’s buttons. They didn’t get very far in the game, but it sure looks like they had fun trying.

Since we’re still in a pandemic, you may want to consider incorporating a mask into your Halloween costume this year. Just a thought.

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A r0tring CS-50 scriber. You type, it writes the letters with a pen on your blueprint or technical drawing.

Plotting To Restore A R0tring CS-50

September 29, 2021 by Kristina Panos 8 Comments

If you’re of a certain vintage and have ever done any technical drawing, chances are good that you used a r0tring of some kind, be it pencil or pen. Well, r0tring makes more than writing implements. They also made electronic scribers — a small plotter that pens ISO lettering on technical drawings based on typed input. This was a huge time saver over doing it freehand or stenciling each letter. The CS-50 is designed to hold the top-of-the-line r0tring drawing pen, which turned out to be the most expensive part of this restoration aside from the time spent sniffing out issues.

[Atkelar] likes to open things up and give them a visual inspection before powering them on. We think this is good practice, even if the suspense kills you. But really, [Atkelar] did so much more than that. He started by replacing the likely late-80s-era coin cell even though it registered north of 3 V. Then he swapped out all the electrolytic caps and one tantalum, cleaned the rubber dome keyboard parts with a cheap electric toothbrush, (another great idea), and completely disassembled the x-y mechanism to clean and re-oil it.

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A shirt with carbon nanotube threads stitched into a shirt monitor the wearer's heart rate.

Sew-able Carbon Nanotube Thread Could Spin A Lot Of Awesome

September 28, 2021 by Kristina Panos 18 Comments

Plenty of people just plain dislike wearing jewelry, even (or especially) smart watches. Nevertheless, they’d like to have biofeedback like everybody else. Well, we watch-less ones have something to look forward to, because a group of graduate students at Rice University have created extremely strong conductive thread woven from carbon nanotubes, which can be sewn into standard athletic clothing and used as electrodes, antennas, or simply as ballistic protection.

At 22 microns wide, the original carbon nanotubes were too skinny to use as thread. Instead, the team braided together three bundles of seven ‘tubes each using the type of machine that model boat builders use to make tiny rigging. Then they zig-zag stitched the threads into a shirt, which gives the stitches added flexibility. This thread maybe as strong and conductive as metal, but the fibers are soft and flexible, and most importantly, machine-washable. Between its strength and conductivity, this thread could have a long list of applications from military down to civilian. Check out the introduction in the video after the break.

For now, the shirt has to be pretty snug, but future garments could easily have higher concentrations of nano-threads in order to get a better signal. Good thing, because we’re still carrying around our COVID nineteen — aka the weight we’ve gained since the longest March of anyone’s life, and never liked tight shirts anyway.

What else can carbon nanotubes do? Plenty, like keep 3D prints from delaminating.

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Illustrated Kristina with an IBM Model M keyboard floating between her hands.

Keebin’ With Kristina: The One Where Shift Happens

September 28, 2021 by Kristina Panos 24 Comments

It’s been an exciting few weeks for me personally on the clacking front. I got a couple of new-to-me keyboards including my first one with ALPS switches, an old TI/99A keyboard with Futaba MD switches, and a couple of what are supposed to be the original Cherry switches (oh man they clack so nicely!) But enough about my keyboard-related fortuitousness, and on to the hacks and clacks!

Putting My Pedals to the Metal

I picked up this Kinesis Savant Elite triple foot pedal from Goodwill. It works fine, but I don’t like the way it’s programmed — left arrow, right arrow, and right mouse click. I found the manual and the driver on the Kinesis website easily enough, but I soon learned that you need a 32-bit computer to program it. Period. See, Kinesis never wrote an updated driver for the original Savant Elite pedal, they just came out with a new one and people had to fork over another $200 or figure something else out.

I’m fresh out of 32-bit computers, so I tried running the program in XP-compatibility mode like the manual says, but it just doesn’t work. Oh, and the manual says you can brick it if you don’t do things correctly, so that’s pretty weird and scary. It was about this time that I started to realize how easy it would be to open it up and just replace the controller with something much more modern. Once I got inside, I saw that all three switches use JST plugs and right angle header. Then I though hey, why not just re-use this set-up? I might have to make a new board, but it how awesome would it be to plug these pedals’ JSTs into my own board?

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