Robot Brutally Chops But Makes Poor Guacamole

Making guacamole by hand normally takes [Estefannie] about 9 minutes. Given her insatiable appetite for the delicious condiment, she spends a lot of time whipping it up in the kitchen at home. Thus, it’s a task ripe for automation, and she set about building a robot to do the job instead.

The robot starts by chopping ingredients like tomato, onion, and avocado with a knife that swivels to cover the entire chopping board surface. Once chopped, a sweeping blade pushes the ingredients into a bowl to form the guacamole.

Initial tests were messy, and ingredients were chopped a little inconsistently. Later work involved reprogramming the machine to chop ingredients separately, rather than all at once, which did improve the quality of the guacamole significantly. However, fundamentally, it wasn’t making good guac, so much as it was making a very chunky salad. It simply couldn’t do all the complicated jobs required to make a smooth, delicious dip.

[Estefannie] elected to instead let it live out its life as a mighty chopper, showing off its prowess by having it attack candy, cake, watermelon, and chocolate, which was pretty fun to watch. It bears noting that if you’re building a robot that swings a blade around, you need to be very careful. If you’re looking for something a bit safer, perhaps a Taco Bot is in your future.

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LEGO Rig Makes Pretty Water Vortexes

LEGO and its Technic line is a great way to learn about all kinds of mechanical things, but it’s also just a whole lot of fun to play with. We suspect the latter reason is what got [Brick Technology] to pursue creating a trippy water vortex with the building toy.

The first design uses a transparent plastic sphere as a water vessel. Inside the sphere is placed a small turbine, turned from the outside via a magnetic coupling. This means the sphere can remain intact, with no holes required, nor complicated seals which can leak. It works well, and produces a vortex when the turbine is spun by a regular LEGO motor. A second attempt elects to rotate the entire sphere itself. Small LEGO wheels are then used to hold the sphere in place on the rapidly spinning turntable. The results are impressive, creating a large and relatively well-formed vortex.

Naturally, though, the video saves the best for last. The big transparent sphere is installed in a rig that surrounds it completely. The sphere itself is spun up thanks to wheels installed on two different axes. This allows the sphere to be spun in various directions under command from a PlayStation controller, creating more complicated vortexes and flow patterns. A set of swiveling casters are provided to hold the sphere in place as it rotates in various directions, and are damped with springs and rubber bands to stop the rig shaking itself apart.

Is there much purpose to this? Well, not on the surface level, no. However, it would certainly make one heck of a rig for shaking up cocktails. Or, if for some reason you need a noisy yet attractive centrifugal separator, maybe this could do the trick. Continue reading “LEGO Rig Makes Pretty Water Vortexes” →

Powering A Cellphone With Gasoline

Batteries are a really useful way to store energy, but their energy density in regards to both weight and volume is disappointing. In these regards, they really can’t compete with fossil fuels. Thus, [bryan.lowder] decided to see if he could charge a phone with fossil fuels as safely and inoffensively as possible.

Obviously, with many national grids relying on fossil fuels for a large part of their generation, most of us are already charging our phones with fossil fuels to some degree. However, the aim here was to do so more directly, without incurring transmission losses from the long runs through the power grid. Continue reading “Powering A Cellphone With Gasoline” →

Hackaday Prize 2022: A Spring-Driven Digital Movie Camera

These days, most of us are carrying capable smartphones with high-quality cameras. It makes shooting video so easy as to take all the fun out of it. [AIRPOCKET] decided to bring that back, by converting an old spring-driven 8mm film camera to shoot digital video.

The camera in question is a magazine-fed Bell & Howell Model 172 from the 1950s. In its original spring-driven form, it could shoot for approximately 35 seconds at a (jerky) frame rate 16 fps.

In this build, though, the film is replaced with a digital imaging system designed to fit in the same space as the original magazine. A Raspberry Pi Zero 2 was pressed into service, along with a rechargeable battery and Pi camera module. The camera is timed to synchronise with the shutter mechanism via a photosensor.

Since it uses the original optics and shutter speed, the resulting video is actually very reminiscent of the Super 8 cameras of the past. It’s an impressive way to get a retro film effect straight into a digital output format. The alternative is to just shoot on film and scan it afterwards, of course! Video after the break.

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Converting An Old ATV To Electric Drive

[RCLifeOn] happened upon an old petrol-powered ATV that had seen better days. He decided it was the perfect candidate for a conversion to electric drive.

First up, the chassis was stripped back and cleaned, before being given a fresh coat of paint. It then got fresh valve stems for the tires and was ready for its drivetrain conversion.

The motor of choice is a brushless type, rated for 42 kW at 120 V. [RCLifeOn] doesn’t have batteries capable of maxing out those specs, yet, but carried on with the build. The motor was mounted on the chassis, and a 3D printed hub was installed to get the sprocket on the end of the motor.

A stress test uphill killed the speed controller. This was not unexpected, as it was a cheap unit severely undersized for the application.

The first drive was rough and ready, as the speed controller wasn’t sensored, the gearing wasn’t quite right, and the chain wasn’t very tight. However, it did successfully make it around the grass, slowly. Further improvements then included a water cooling circuit for the speed controller and the addition of a battery compartment. That wasn’t enough to stop the speed controller bursting into flames during a difficult uphill climb, though.

Fundamentally, though, the project shows promise. Bigger batteries, a sensored speed controller, and appropriate gearing should make it a quick beast. 42 kW of power is a good amount for a light ATV, plus there’s the benefit of instant-on torque from an electric motor.

We’ve seen [RCLifeOn] tackle some high-powered electric builds before, like his impressive powered surfboard.  With the right parts, we’re sure he’ll have this thing ripping about at pace before long!

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The Cheat Way To Perfectly Split An Oreo

Believe it or not, much research has been done in how to perfectly split Oreos with an even amount of cream on both sides. Early studies suggested it simply wasn’t possible, with one side always getting the majority of the cream.  However, [Ian Charnas] has now found a sneaky workaround.

First attempts involved heating in a microwave or chilling the cookies in the freezer. Neither helped in the slightest. A vacuum chamber only served to delaminate the cream from both sides of the cookie entirely, while water jet cutting made an awful mess.

[Ian] ended up realizing that crack propagation could be used to prepare Oreos for a perfect split. A knife was used to score a groove all around the cream layer, right down the middle. The Oreos were then frozen, turning the cream effectively solid. When the Oreo is then twisted, the groove serves as a starting point for a crack that propagates across the surface, splitting the cream neatly between both halves.

[Ian] took things further by building a 3D-printed lathe that grooves Oreos using a sterilized scalpel blade. This allows cookies to be quickly prepped for a perfect split. However, you are left eating frozen Oreos at the end of it, with some sacrifices to freshness.

It’s a neat way to approach the Oreo splitting problem, even if it’s only one step removed from simply using a knife. We’ve seen [Ian]’s work before, too, in the form of the radioactively-powered Game Boy. Video after the break.

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Hackaday Prize 2022: A Sun-Chasing Robot

There’s plenty of power to be had from the sun, but you need to be out of the shade to receive it. [Dennis] built a robot by the name of Sun Chaser that has the smarts to go where the sun is shining.

Sun Chaser is essentially a robotic solar panel, tasked with filling up its batteries as much as possible. It can then be used as a power supply for campsites or other remote areas, and used to charge devices as required.

A Raspberry Pi runs the show, paired with a Squid motor controller to run the drive system. Sun Chaser has a motorized solar panel onboard which can track the sun for maximum output, with the aid of six photoresistors to guide the positioning. A camera is used to image the area around Sun Chaser, too, and processing is used to identify sunny regions which will provide the most energy.

Even outside of its useful applications, the idea of having a robot that can run around and keep itself juiced up is a fun one. Solar power gives a robot a greater sense of autonomy, after all. This author has experimented in this field to great enjoyment, too. Video after the break.

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