Martian Wheel Control Algorithms Gain Traction

February 15, 2022 by 13 Comments

Imagine the scene: You’re puttering along in your vehicle when, at least an hour from the nearest help, one of your tires starts losing air. Not to worry! You’ve got a spare tire along with the tools and knowhow to change it. And if that fails, you can call roadside assistance. But what if your car isn’t a car, has metal wheels for which no spares are available, and the nearest help is 200 million miles away? You just might be a Jet Propulsion Laboratory Engineer on the Curiosity Mars Rover mission, who in 2017 was charged with creating a new driving algorithm designed to extend the life of the wheels.

High Performance Rock Crawler, Courtesy Spidertrax.com License: CC BY 3.0

You could say that the Curiosity Mars rover is the ultimate off-road vehicle, and as such it has to deal with conditions that are in some ways not that different from some locations here on Earth. Earth bound rock crawlers use long travel suspensions, specialized drivetrains, and locking differentials to keep the tires on the ground and prevent a loss of traction.

On Mars, sand and rocks dominate the landscape, and a rover must navigate around the worst of it. It’s inevitable that, just like a terrestrial off-roader, the Mars rovers will spin a tire now and then when a wheel loses traction. The Mars rovers also have a specialized drivetrain and long travel suspensions. They don’t employ differentials, though, so how are they to prevent a loss of traction and the damaging wheel spin that ensues? This where the aforementioned traction control algorithm comes in.

By controlling the rotation of the wheels with less traction, they can still contribute to the motion of the vehicle while avoiding rock rash. Be sure to check out the excellent article at JPL’s website for a full explanation of their methodology and the added benefits of uploading new traction control algorithms from 200 million miles away! No doubt the Perseverance Mars rover has also benefited from this research.

But why should NASA get to have all the fun? You can join them by 3d printing your own Mars rover and just maybe some Power Wheels derived traction control. What fun!

Anti-Curl Sandpaper Storage Is Impressive

February 15, 2022 by 15 Comments

Maybe it’s the humidity, maybe it’s the cold weather. Something is making [Laura Kampf]’s nice fabric-backed sandpaper curl up into scrolls the second it comes out of the package. So you can understand why she urgently wanted to make a storage system that would be easy to flip through like a record bin, but also provide enough pressure to keep the papers flat.

Although [Laura] didn’t know what exactly the end result would be, she got started on it anyway — that’s a great way to get more projects off the drawing board and past the finish line. It worked out, because she got a great idea while building the box and using nice cam clamps to hold the finger joints together as the glue dried. Since she already had a bunch of these cam clamps in different lengths lying around, why not use a couple of them for this?

[Laura] has two major classifications of sandpaper — paper-backed and fabric-backed — and built them separate boxen using two clamps for each box. She joined the pins with a DIY handle in order to move the cams in unison, so all she has to do is pull out to flip through the papers, and push the handle back and down to re-pressurize the stack for storage. Be sure to check out the build and demo video after the break.

While DIY clamps are often wood and metal affairs, it’s good to have 3D printing in your corner.

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PS2 Memory Card ISO Loader Offers Classic Gaming Bliss

February 15, 2022 by 30 Comments

It used to be that to play a console game, you just had to plug in a cartridge or put a CD/DVD in the optical drive. But these days, with modern titles ballooning up to as much as 100 GB, you’ve got no choice but to store them on the system’s internal hard disk drive. While that can lead to some uncomfortable data management decisions, at least it means you don’t have to get up off the couch to switch games anymore.

Which is precisely why the MC2SIO project for the PlayStation 2 is so exciting. As [Tito] explains in his latest
Macho Nacho Productions video, this simple adapter lets you connect an SD card up to the console’s Memory Card slots and use that to hold ISOs of your favorite games. With the appropriate homebrew software loaded up, your PS2 becomes a veritable jukebox of classic games.

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Filament Dry Box Design Goes Way Over The Top

February 15, 2022 by 36 Comments

There’s a fine line between simple feature creep and going over the top when it comes to project design. It’s hard to say exactly where that line is, but we’re pretty sure that this filament dry box has at least stepped over it, and might even have erased it entirely.

Sure, we all know the value of storing 3D printer filament under controlled conditions, to prevent the hygroscopic plastics from picking up atmospheric moisture. But [Sasa Karanovic] must really, REALLY hate the printing artifacts that result. Starting with a commercially available dry box that already had a built-in heating element, [Sasa] took it to the next level by replacing the controller and display with an ESP32. He added a fan to improve air circulation inside the enclosure and prevent stratification, as well as temperature and humidity sensors. Not satisfied with simply switching the heating element on and off at specific setpoints, he also implemented a PID loop to maintain a constant temperature. And of course, there’s a web UI and an API available for third-party control and monitoring.

The video below details [Sasa]’s design thoughts and goes into some detail on construction and performance. And while we may kid that this design is over-the-top, what really comes through is that this is a showcase for design ideas not only for one application, but for hardware projects in general. There are certainly simpler heated dry box designs, and zero-cost solutions as well, but sometimes going overboard has its own value too.

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“So Long,” Said All The Tank-Driving Fish

February 15, 2022 by 19 Comments

Though some of us are heavily assisted by smart phone apps and delivery, humans don’t need GPS to find food. We know where the fridge is. The grocery store. The drive-thru. And we don’t really need a map to find shelter, in the sense that shelter is easily identifiable in a storm. You might say that our most important navigation skills are innate, at least when we’re within our normal environment. Drop us in another city and we can probably still identify viable overhangs, cafes, and food stalls.

The question is, do these navigational skills vary by species or environment? Or are the tools necessary to forage for food, meet mates, and seek shelter more universal? To test the waters of this question, Israeli researchers built a robot car and taught six fish to navigate successfully toward a target with a food reward. This experiment is one of domain transfer methodology, which is the exploration of whether a species can perform tasks outside its natural environment. Think of all the preparation that went into Vostok and Project Mercury.

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Dead Mouse Reincarnated As Macropad

February 15, 2022 by 9 Comments

[Taylor] wanted to join the cool kids club and build a macropad for CAD work and video editing, but didn’t want to do it the traditional way with an Arduino. We can get behind that. In fact, [Taylor] wanted to reuse some old piece of tech if possible, which is even better. With a little luck, they found a used gaming mouse with a set of 12 tiny macro buttons on the side that were ripe for reuse. Only the scroll wheel was reported to be broken.

After verifying that all the macro buttons worked, [Taylor] tore down the mouse and extracted the daughterboard, then removed the sticker that held the rubber dome actuators in place. Then they wired up twelve Kailh box jades to the pads, doing some nice diagonal work with bare 30 AWG wire to join all the common pins together.

[Taylor] designed and printed a simple enclosure that’s a slim 21.5 mm tall including the switch plate, and then made a dozen keycaps to match. That was until [Taylor] remembered some relegendable keycaps they had lying around — the kind that let you print your own labels and trap them underneath clear plastic. The only problem was that they are stemmed for some cylindrical actuator, so [Taylor] designed an adapter piece so they would fit on MX-style sliders. Be sure to check out the build video after the break.

If for some reason box jades aren’t clicky and satisfying enough for you, try making your own maglev Hall-effect switches. These days, you even have design options.

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First Days With A New Microscope

February 15, 2022 by 35 Comments

For big-ticket purchases, I tend to do a lot of research before I open my wallet. I like to at least have the illusion that when I send my money off to a far-away stranger, I’m likely to get back something of equal value in a reasonable timeframe that does what I want it to do. So I tend more toward the “analysis paralysis” end of the spectrum, where I pore over so many specs and reviews that I end up buying nothing.

While that sounds like a bad thing, and sometimes is, I find that it tends to help me avoid rashly spending money on things that aren’t going to work for me. This is especially true in the area of tools, where while I’m trapped in my analysis loop, I often find a workaround or substitute that’s good enough to get the job done.

For some things, though, there is no substitute, and when you start working with SMD components that you’d have a hard time telling from a grain of salt, you’re probably going to need a microscope. I recently determined that this was where I was in my electronics journey, and now that I’ve worked my way through the analysis and procurement phase of the process, I thought I’d share my first impressions of my microscope, and what it’s like to get used to working with one.

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