Lawny Five Keeps Lawn Mowed, Snow Plowed

February 8, 2024 by 10 Comments

Although there’s been considerable excitement over the past half century of a Jetsons-like robotic future, outside of a few niche uses of our day-to-day lives there hasn’t been much in the way of robotic assistants coming to ease our physical household workloads. Sure, robots exist in manufacturing and other industrial settings, but the vast majority of us won’t see a robotic revolution unless we make it for ourselves. To that end, [Jim] has begun construction of a robot that can at least mow his lawn and eventually plow his driveway, among other potential tasks.

The robot, called the Lawny Five, is a tracked vehicle currently under remote control but with a planned autonomous capability. The frame includes a set of caster wheels at the front to take advantage of the differential steering of the tracks, and between everything is where the mower, plow, or other tool can sit. The attachment system is based on a 2″ receiver hitch, allowing the robot to eventually change tools at will while still preserving the usefulness of the tools in their original state. The robotic platform has been tested with the mower on a wet lawn with a 20° slope and showed no signs of struggle (and didn’t damage the grass) so it’s ready to take on more challenging tasks now as well.

With the core of the build out of the way, [Jim] is well on his way to a robotic lawnmower and potentially even an autonomous one, not to mention one with interchangeable tools that he hopes will be put to work in other ways like parking his boat in a small space by his house. For those maintaining a piece of land a little more involved than suburban turfgrass, there are other robotic platforms capable of helping out farmers with things like planting, watering, and weeding.

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3D Printing Silicone Parts

February 8, 2024 by 6 Comments

Silicone is a useful material for many purposes. Traditionally, creating something out of silicone required injection molding. That’s not difficult, but it does require a good bit of setup. As [Formlabs] points out in a recent video, there are at least three other routes to create silicone parts that utilize 3D printing technology that might fit your application better, especially if you only need a few of a particular item. You can see the video below.

The three methods are either printing silicone directly, printing a mold, casting silicone, or using high-performance elastomers, which are very silicone-like. Of course, as you might expect, some of this is aimed at prompting some of [Formlab’s] products, like a new silicone resin, and you can’t blame them for that.

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A Tube Tester Laid Bare

February 8, 2024 by 13 Comments

There’s still a mystique around vacuum tubes long after they were rendered obsolete by solid state devices, and many continue to experiment with them. They can be bought new, but most of us still come to them through the countless old tubes that still litter our junk boxes. But how to know whether your find is any good? [Rob’s Fixit Shop] took a look at a tube tester, once a fairly ubiquitous item, but now a rare sight.

To look at it’s a box with an array of tube sockets, a meter, and a set of switches to set the pinout for the tube under test. We expected it to use a common-cathode circuit, but instead it measures leakage between the grid and the other electrodes, a measure of how good the vacuum in the device is. In a worrying turn this instrument can deliver an electric shock, something he traces to a faulty indicator light leading to the chassis. We are however still inclined to see it as anything but safe, because the lack of mains isolation still exposes the grid to unwary fingers.

All in all though it’s an interesting introduction to an unusual instrument, and given a suitable isolating transformer we wouldn’t mind the chance to have one ourselves. If you need to test a tube and don’t have one of these, don’t worry. It’s possible to roll your own.

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The End Of Landlines?

February 8, 2024 by 94 Comments

Imagine if, somehow, telephones of all kinds had not been invented. Then, this morning, someone entered a big corporation board room and said, “We’d like to string copper wire to every home and business in the country. We’ll get easements and put the wires on poles mostly. But some of them will go underground where we will dig tunnels. Oh, and we will do it in other countries, too, and connect them with giant undersea cables!” We imagine that executive would be looking for a job by lunchtime. Yet, we built that exact system and with far less tech than we have today. But cell phones have replaced the need for copper wire to go everywhere, and now AT&T is petitioning California to let them off the hook — no pun intended — for servicing landlines.

The use of cell phones has dramatically decreased the demand for the POTS or plain old telephone service. Even if you have wired service now, it is more likely fiber optic or, at least, an IP-based network connection that can handle VOIP.

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Revisiting A Z80 Game From 1990

February 8, 2024 by 16 Comments

Back in the days of 8-bit computers, like no doubt many readers of similar age, we wrote little games. First in BASIC, then augmented with little machine code speed-ups. We didn’t come close to [Óscar Toledo Gutiérrez] though, who’s reverse engineering a 2K all-machine-code game he wrote back in 1990. As a tale of software archaeology it’s fascinating.

The game itself is an avoid-the-monsters platformer with plenty of ladders for the little sprite-based protagonist to run down. The computer was a Mexican homebrew educational machine with a TMS9118 display chip and an AY-3-8910 synthesizer, so the result had both color and music. His run through the code breaks it down neatly into individual sections, so it’s possible to see what’s going on without an in-depth knowledge of machine code.

He readily admits it bears all the hallmarks of an 11-year-old’s knowledge at the time, and that it has some parts less elegant, but nevertheless it’s something of an achievement at any age. It was out of date gameplay-wise in 1990 but in 1982 it could probably have been bought on a tape by eager kids. Here in 2024 he’s got it for download should you have a Colecovision or an MSX. There’s a gameplay video below the break, take a look.

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How Airplanes Mostly Stopped Flying Into Terrain And Other Safety Improvements

February 8, 2024 by 13 Comments

We have all heard the statistics on how safe air travel is, with more people dying and getting injured on their way to and from the airport than while traveling by airplane. Things weren’t always this way, of course. Throughout the early days of commercial air travel and well into the 1980s there were many crashes that served as harsh lessons on basic air safety. The most tragic ones are probably those with a human cause, whether it was due to improper maintenance or pilot error, as we generally assume that we have a human element in the chain of events explicitly to prevent tragedies like these.

Among the worst pilot errors we find the phenomenon of controlled flight into terrain (CFIT), which usually sees the pilot losing track of his bearings due to a variety of reasons before a usually high-speed and fatal crash. When it comes to keeping airplanes off the ground until they’re at their destination, here ground proximity warning systems (GPWS) and successors have added a layer of safety, along with stall warnings and other automatic warning signals provided by the avionics.

With the recent passing of C. Donald Bateman – who has been credited with designing the GPWS – it seems like a good time to appreciate the technology that makes flying into the relatively safe experience that it is today.

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The Revolver: A 3D-Printed… Screwdriver!

February 8, 2024 by 19 Comments

You know those “What my friends think I do” vs “What I actually do” memes? Well there should be one for 3D printing that highlights what you think you’ll do before buying your first printer vs what you actually wind up printing once you get it!

However, thanks to [Revolver3DPrints] you can fulfill your dream of printing a useful tool that looks like a commercial product, the Revolver two-speed screwdriver. The screwdriver isn’t motorized, but it has an interesting midsection that can be rotated to spin the bit, and you can select between a speed and torque mode.

The Revolver isn’t a solution looking for a problem. The designer noted a few issues with normal screwdrivers. They are hard to get into tight spaces, which was the biggest issue. The Revolver is compact, and since you turn its midsection, you don’t have to have clearance for your hand on the top. The gear ratios allow you to apply more torque without needing a long handle.

As you may have guessed, the internal arrangement is a planetary gear drive. You might consider if you want to print this using resin or FDM printing. You also need some screwdriver bits, some glue, and a few magnets to complete the project. If you prefer to make a motorized screwdriver, we’ve seen that done, too.

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