Bonkers Nerf Blaster Sprays Balls Everywhere

March 14, 2024 by Zoe Skyforest 3 Comments

Nerf blasters are fun toys, to be sure. However, they’re limited by factors like price and safety and what Hasbro thinks parents will put up with. Few caregivers would ever countenance a build like this one from [ItllProbablyWork].

It’s a blaster designed to fire 48 darts in a second or so, or a truly ludicrous 288 Nerf balls. Like so many rapid fire blaster designs, it’s based on a pair of rotating wheels which fling darts out at rapid speed. The trick to the rapid fire ability is the delivery of ammunition. In this case, the blaster has a rotating drum of 12 barrels, which can each be loaded with 4 darts or 24 balls. As the drum rotates into position, a trigger mechanism unlatches a spring which forces the contents of the barrel out through the wheels and on to the target.

It’s mostly pretty good with darts, but with balls, it tends to send them flying everywhere, including jamming a bunch into the blaster’s internals. It is very funny to watch, though.

We’ve seen some other great blaster builds recently, too. Video after the break.

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Building A Hydraulic Loader For A Lawn Tractor

March 14, 2024 by Zoe Skyforest 10 Comments

Lawn tractors are a great way to mow a large yard or small paddock. They save you the effort of pushing a mower around and they’re fun to drive, to boot. However, they can be even more fun with the addition of some extra hardware. The hydraulic loader build from [Workshop from Scratch] demonstrates exactly how.

The build is based around a John Deere LX188 lawn tractor, which runs a 17 horsepower Kawasaki engine and features a hydrostatic transmission. It’s a perfectly fine way to mow a lawn. In this case, though, it’s given new abilities with the addition of a real working loader. It’s fabricated from raw steel from the arms right down to the bucket. It’s all run from a hydraulic pump, which is mounted to the engine via an electromagnetic clutch. The clutch can be engaged when it’s desired to use the hydraulics to actuate the loader.

As you might expect, the humble lawn tractor isn’t built for this kind of work. Thus, to support the extra equipment, the mower was also given some frame reinforcements and a wider track for stability.

If you’re trying to give your neighbours mower envy, this is how you do it. Or, you could go another route entirely. Video after the break.
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Dev Board Watch Takes Path Of Least Resistance

March 14, 2024 by Zoe Skyforest 9 Comments

Building your own watch or clock is kind of a maker’s rite of passage. Once upon a time, if you went with a wrist watch, you’d typically work on producing your own compact PCB with everything crammed into a typical watch form factor, maybe relying on a simple binary output for compactness and simplicity. Times have changed, however, and [Arnov]’s design is altogether different in its construction.

The build relies on a XIAO ESP32-C3 microcontroller board as the brains of the operation. It’s paired with the XIAO expansion board. It’s designed as a carrier for the ESP32-C3, giving it a bunch of IO that’s accessible over readily-accessible connectors. It also features a display, a real-time clock, and a battery — pretty much the three main things you’d need to add to an ESP32 to turn it into a watch.

Thus, with the electronics pretty much done, it was simply up to [Arnov] to turn the device into a watch. He achieved this by screwing the frame and strap of an old Casio watch to a 3D printed carrier for the XIAO expansion board. With that done, it was simply a matter of writing the code to show the time from the RTC on the display. There’s no connectivity features, no smart stuff going on — just the time and date for your perusal.

Some might decry the project for simply slapping a watch band on a devboard. Or, you could look at how this indicates just how fast and easy development can be these days. Once upon a time, you could spend weeks trying to find a cheap display and then further weeks trying to get it working with your microcontroller. Now you can spend $20, get the parts in a few days, and get your project blasting along minutes later.

If you’ve done an altogether more ornate watch build of your own, we’d love to see that, too. Show us on the tipsline!

A Compact SCARA Arm Plotter

March 14, 2024 by Zoe Skyforest 4 Comments

If you’re unfamiliar with SCARA robots, the acronym stands for Selective Compliance Assembly Robot Arm. This refers to the fact that the arms are rigid in the Z axis but somewhat compliant in the X and Y axes, and that they’re often used for assembly tasks. In any case, you can spend a great deal of money equipping your factory with these robots, or you can build your own for the fun of it. If you’re not endowed with a seven-figure investment for opening a production plant, consider exploring [tuenhidiy’s] project instead.

The build enlists an Arduino Mega as the brains of the operation. It’s paired with a RAMPS controller for running a pair of NEMA 17 stepper motors that actually move the arm in the X-Y plane. Additionally, a tray eject mechanism from a CD/DVD drive is enlisted to act as the Z axis. The frame is assembled from PVC plumbing components and a small amount of aluminium T-slot profile.

The resulting arm isn’t fast in the video we see of the build, but it works as a basic plotter without too much complaint. The benefit of the Z-axis in this case is obvious, as it allows the pen to be lifted off the page where necessary.

We’ve seen plenty of good plotter designs around these parts before, too. Video after the break.

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Playing Audio On The Pi Pico With No DAC To Speak Of

March 12, 2024 by Zoe Skyforest 24 Comments

Normally, if you want to play music or other audio on a microcontroller, you need to get yourself a DAC. Or at least, that’s the easiest way to go about it and the one most likely to get you good, intelligible audio. You don’t have to go that way, though, as [antirez] demonstrates.

[antirez] decided to do this with a Pi Pico, but it’s applicable to other microcontrollers too. It’s all done with a single pin and a PWM output. The PWM output is set to a very high frequency beyond human hearing. In this case, it was 100 KHz. Then, the duty cycle of the PWM is changed to essentially output various average voltage levels at the pin. Vary the output voltage as per your desired sound file by using each sample to vary the duty cycle of the PWM. Voila! You can output whatever sound you want on that pin! [antirez] steps through the basics of doing this, including processing simple WAV files into a raw format that can be dumped into MicroPython code.

There’s no sound sample on the project page, and we’d have to assume it sounds pretty crunchy when hooked up to a speaker. And yet, it could prove a useful technique if you’re designing your own audio greeting cards or something, so keep that in mind!

CT Scan Reveals Secrets Of Heinz’s New Ketchup Cap

March 7, 2024 by Zoe Skyforest 57 Comments

Ketchup bottles are a solved technology, right? Wrong! As it turns out, there is still great development being done in this space. Industrial imaging company Lumafield reveals to us the secrets of Heinz’s new ketchup bottle cap, reportedly the result of a seven-figure investment and eight long years of toil.

Lumafield put the cap in a CT scanner to generate three-dimensional cutaway images of the cap’s internal structure. The trick of the new cap is in how it compares to the old design. The previous solution used multiple different plastics: likely polypropylene for the cap itself, along with a small amount of silicone for the flexible nozzle valve. The point of the valve was to regulate the flow of ketchup so the bottle squirts out the red goop in a predictable fashion.

The problem with the old cap is that the use of two materials both makes it more expensive to manufacture, and practically impossible to recycle. A solution was needed, and Heinz finally found one.

The new cap, which is fully recyclable, takes advantage of the properties of ketchup itself. As the ketchup is squeezed out of the bottle, it passes through a complicated array of channels before it gets to the nozzle outlet itself. As a sheer-thinning fluid, ketchup gets less viscous the more its under strain. Thus, as it deforms around the complex channels, it becomes less viscous and more likely to flow out at a predictable rate, rather than in thick gloopy spurts.

It’s amazing to think how much work goes into a simple ketchup cap, and yet, millions of dollars are on the line in projects like these. This isn’t the first time Lumafield used their tech to peel back the layers on a piece of common tech — last year we covered their investigation into what’s inside various AirPod knockoffs.

Stacking Solar Cells Is A Neat Trick To Maximise Efficiency

March 7, 2024 by Zoe Skyforest 51 Comments

Solar power is already cheap and effective, and it’s taking on a larger role in supplying energy needs all over the world. The thing about humanity, though, is that we always want more! Too much, you say? It’s never enough!

The problem is that the sun only outputs so much energy per unit of area on Earth, and solar cells can only be so efficient thanks to some fundamental physical limits. However, there’s a way to get around that—with the magic of tandem solar cells!

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