Hackaday Prize 2023: Computer Vision Guides This Farm Mower

September 24, 2023 by Jenny List 8 Comments

It’s a problem common to small-scale mixed agriculture worldwide, that of small areas of grass and weeds that need mowing. If you have a couple of sheep and enough electric fence there’s one way to do it, otherwise, if you rely on machinery, there’s a lot of hefting and pushing a mower in your future. Help is at hand, though, thanks to [Yuta Suito], whose pylon-guided mower is a lightweight device that mows an area defined by a set of orange traffic cones. Simply set the cones around the edge of the plot, place the mower within them, and it does the rest.

At its heart is a computer vision system that detects the cones and estimates distance from them by their perceived size. It mows in a spiral pattern by decreasing the cone height at which it turns, thus covering the whole area set out. Inside is a Raspberry Pi doing the heavy lifting, and because it’s designed for farmland rather than lawns, it has an adaptive track system to deal with obstacles. In its native Japan there is an ageing rural population, so it is particularly suitable for being operated by an older person. See it in action in the video below the break.

A robotic mower aimed at farms is certainly unusual here, but we’ve seen a lot of more conventional lawnmowers.

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Powder Your Prints For Baby-Smoothness

September 24, 2023 by Kristina Panos 46 Comments

Layer lines are a dead giveaway to non-normies that a thing was 3D printed. There are things you can do to smooth them — sanding, chemical smoothing, and fillers come to mind. Although this technique technically uses all three, it starts with something very simple.

In the video after the break, [DaveRig] gets right to the point: baby powder and resin mixed together make a fine smoothing agent when cured. Having read about it online, he decided to give it a try.

Starting with a half sphere that had admittedly pretty big layer lines, [DaveRig] mixed up enough resin and baby powder to make the consistency of milk or cream. Then he put five coats on, curing and sanding with 120 in between each one.

Then it’s on to standard post-processing stuff. You know, wipe it down with alcohol, sand it a little more, wet sand, and then it’s on to the airbrush and clear-coat. The end result looks to be as smooth as your average bowling ball, as you can see in the main photo.

What’s your favorite post-processing method? Have you tried annealing them in salt?

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A wooden digital clock with a metal knob on one end

Hackaday Prize 2023: Stretch Your Day With This 29-Hour Clock

September 24, 2023 by Robin Kearey 9 Comments

Modern life can be stressful. Many of us struggle to balance work, family, exercise, and an ever-growing list of hacking projects, all of which claim our attention during the day. If you sometimes feel that those 24 hours just don’t cut it, you might be in luck: [HIGEDARUMA] has built a clock that can stretch your day by up to five hours.

Sadly, [HIGEDARUMA] hasn’t invented time travel (yet). What his clock does instead is slow down its own pace in the evening to push back the midnight hour. When it finally does reach 12:00 a.m., the clock’s pace is accelerated to ensure it’s back in sync with the rest of the world by six in the morning. It might seem silly, but there is a certain logic to it: [HIGEDARUMA] explains that evenings felt much longer when he was a child and that he would like to try and experience that again. Our sense of time may change over our lifetime, even if the actual passage of time doesn’t.

Timescales aside, the 29-hour clock is a neat piece of work from a hardware point of view. The case is made from 4 mm laser-cut MDF with wood-grain foil on the outside. Inside, there’s an ESP32 to run the show, along with an RTC module and three four-digit seven-segment LED displays. A chunky “volume” knob on the front lets you choose how much you’d like your day to be stretched.

We’ve seen clocks with non-linear dials before, as well as extremely linear ones, but this might be the first one with a non-constant pace. It makes us wonder what the passage of time feels like for those frozen in ice for 46,000 years.

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Input Device Gets New Input Device

September 23, 2023 by Kristina Panos 6 Comments

One of the nicest things about a trackpoint is that you don’t have to take your hands off the keyboard. One of the worst things about a trackpoint is its usual placement, which can force a weird hand position that can cause repetitive stress injury.

[notshitashi] has done an incredible job of adding a trackpoint to the Glove80 wireless split keyboard. It must have been really scary to drill holes in the palm rests of such a nice and not-cheap keyboard, but [notshitashi] soldiered on nonetheless, and the end result looks great.

Starting with a trackpoint module from Ali, [notshitashi] found that it didn’t fit the palm rest without being trimmed down, so they desoldered the business part from the main PCB and reattached it with wires. They had to go through a few of them to get it just right, but that’s the way it goes sometimes.

[notshitashi] calls this “a bit of a cheat and dirty hack” because the trackpoint module is wired and, therefore, a separate USB HID. Yes, the Glove80 has GPIO connectors in both halves, but the problem is that stock ZMK has yet to support pointing devices. We don’t care; this is quite the elegant hack anyway.

Want to jazz up your mechanical keyboard with a trackpoint? Here’s a handy guide. Or, you can perform a transplant.

Hackaday Prize 2023: A 3D Printed Vertical Wind Turbine

September 23, 2023 by Jenny List 23 Comments

We feature a lot of off-grid power projects here at Hackaday, whether they’re a micropower harvester or something to power a whole house. Somewhere in the middle lies [esposcar90]’s 3D-printed vertical wind turbine, which it is claimed can deliver 100 watts from its diminutive tabletop package.

It’s designed to be part of a package with another turbine but makes a very acceptable stand-alone generator. The arms have large scoop-like 3D-printed vanes and drive a vertical shaft up the centre of the machine. This drives a set of satellite gears connected to a pair of DC permanent magnet motors, which do the work of generating. For different wind situations, there are even some differing STL gear choices to speed up the motors. The motors are 12V devices, so we’re guessing the output voltage will be in that ballpark. However, it’s not made entirely clear in the write-up.

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A modern recreation of von Guericke's electrostatic generator

Electrostatic Generator Project Starts With Molten Sulfur

September 23, 2023 by Robin Kearey 38 Comments

Although the basic concept of electrostatic attraction has been known since ancient times, it was only in the 17th century that scientists began to systematically investigate electrostatics. One of the first to explore this new field was Otto von Guericke, who constructed an electrostatic generator to help with his experiments. [Markus Bindhammer] has reconstructed this machine, which formed the basis for later work by the likes of Wimshurst and Van de Graaff. [Markus] kept his machine in an almost period-correct fashion.

Von Guericke’s machine consists of a sulfur ball mounted on a spindle that allows it to be rotated and rubbed against a piece of cloth. By doing so, the ball gains a charge that can be used to attract small pieces of material. [Markus] built a neat wooden frame with faux-antique carved legs and installed a handle, a spindle, and a belt-drive system to rotate whatever’s mounted on the spindle at high speed.

All of this is beautifully documented in [Markus]’s video, but by far the most interesting part of his project is the process of manufacturing the sulfur ball. If you’ve always wanted one, here’s how to make one: first, melt some pieces of pure sulfur in a round-bottom flask using an oil bath. Then, turn on your vacuum pump to remove any air or water vapor trapped inside the liquid. Once the liquid is nice and clear, let it cool down and solidify very slowly; the sulfur ball can then be released from its container by breaking the glass with a hammer.

While it sounds simple, we can imagine it took a bit of experimenting to get all those steps just right. The end result is a simple but useful machine to demonstrate basic electrostatics, which [Markus] is planning to use in science lectures. There are lots of interesting experiments you can do with static electricity, including building a basic motor.

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Reviving An Old Lime-E Beta Rideshare E-Bicycle

September 23, 2023 by Maya Posch 27 Comments

What do you do when you come across a cheap electric bicycle on Facebook Marketplace from a seller who has a few hundred of the same ones available? If you’re someone like [Max Helmetag], you figure that it’s probably legit since nobody would be reselling hundreds of Lime ridesharing e-bikes. Thus, it makes for an excellent project to see how usable an old ridesharing bicycle is. According to the information on the e-bike’s frame, it was manufactured in 2017, and based on the plastic still covering parts of the bike, it had barely been used, if at all.

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