Solving Cold Cases With Hacked Together Gear

People go missing without a trace far more commonly than any of us would like to think about. Of course the authorities will conduct a search, but even assuming they have the equipment and personnel necessary, the odds are often stacked against them. A few weeks go by, then months, and eventually there’s yet another “cold case” on the books and a family is left desperate for closure.

But occasionally a small team or an individual, if determined enough, can solve such a case even when the authorities have failed. Some of these people, such as [Antti Suanto] and his brother, have even managed to close the books on multiple missing person cases. In an incredibly engrossing series of blog posts, [Antti] describes how he hacked together a pair of remotely operated vehicles to help search for and ultimately identify sunken cars.

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Programming Robots Is Hard, Figuring Out How To Make It Easier Is Harder

[Benjie Holson] is an experienced roboticist and wrote an interesting article published on IEEE Spectrum about how the idea most people have of non-roboticists is a myth, and efforts to target this group with simplified robotic frameworks tend to be doomed.

Now, let’s make a couple things absolutely clear right up front: He is not saying robots shouldn’t be easier to program, nor is he saying that non-roboticists literally do not exist (of course they do.) The issues he’s highlighting really come down to product design.

[Benjie] points out that programming robots is super hard, but it’s also hard in more than one way and for more than one reason. And when people try to create a product to make it easier, they tend to commit two big product design no-no’s: they focus on the wrong hard parts, and they design their product for a vaguely-defined audience that doesn’t really exist. That group is the mythical non-roboticist.

These are actually very solid points to make in terms of product design in general. Designing a product that solves the wrong problems for a poorly-defined group isn’t exactly a recipe for success. [Benjie]’s advice on making a truly effective and useful API framework that genuinely lowers the bar of complexity in a useful way is similarly applicable to product design in general.

His first piece of advice is not to design for poorly-defined amorphous groups. Your product should serve actual needs of actual users. If you cannot name three people you have actually spoken to who would be helped by your product, you are designing for an amorphous (and possibly imaginary) group.

The second is to design as though your users are just as smart as you are, just less tolerant of problems stemming from rough edges like compatibility and configuration issues. Remove those so that your users can get useful work done without having to re-invent the wheel, or resort to workarounds.

Robotic frameworks like ROS are useful and extensible, but whenever someone attempts to focus on creating a simplified framework, [Benjie] says they tend to step on the same rakes. It’s a mistake [Benjie] has committed himself, and see repeated by others. We think his advice is good product design advice in general, whether for designing APIs or something else.

Screwless Eyeballs Are A Lesson In Design-For-Assembly

[Will Cogley] makes eyeballs; hey, everyone needs a hobby, and we don’t judge. Like all his animatronics, his eyeballs are wondrous mechanisms, but they do tend toward being a bit complex, especially in terms of the fasteners needed to assemble them.

But not anymore. [Will] redid his eyeball design to be as easy to assemble as possible, and the results are both impressive and instructive. His original design mimics real eyeballs quite well, but takes six servos and a large handful of screws and nuts, which serve both to attach the servos to the frame and act as pivots for the many, many linkages needed. The new design has snap-fit pivots similar to Lego Technic axles printed right into the linkage elements, as well as snap connectors to hold the servos down. This eliminates the need for 45 screws and cuts assembly time from 30 minutes to about six, with no tools required. And although [Will] doesn’t mention it, it must save a bunch of weight, too.

Everything comes at a cost, of course, and such huge gains in assembly ease are no exception. [Will] details this in the video below, including printing the parts in the right orientation to handle the forces exerted both during assembly and in use. And while it’s hard to beat a five-fold reduction in assembly time, he might be able to reduce that even more with a few print-in-place pivots.

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Foosbar: The World’s Best* Foosball Robot From Scratch

[Xander Naumenko] is back with another bonkers project. This is the same creator that built a working 32-bit computer inside a Terraria world. This time it’s a bit more physical of a creation: a self-playing foosball table.

We’re not sure of the impetus for this idea, but we’re delighted to see the engineering it took to make it work. It sounds so simple. It’s just servos mounted on linear actuators, right? Oh, and some computer vision to determine where the ball actually is on the table. And the software to actually control the motors, pass the ball around, and play offense and defense. So maybe not so simple. All the code and some other resources are available under the MIT license.

As to while the claim of “best” foosball robot has an asterisk? That’s because, although we’ve seen a few potential competitors over the years, there isn’t yet a world foosball competition. We’re hoping that changes, as a tournament of robots playing foosball sounds like a sports event we’d show up for!

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Gears Are Old And Busted, Capstans Are Cool

Zero backlash, high “gear” reduction, high torque transparency, silent operation, and low cost. What is this miracle speed reduction technology, you ask? Well, it’s shoelaces and a bunch of 3D printed plastic, at least in [Aaed Musa]’s latest installment in his series on developing his own robot dog.

OK, the shoelaces were only used in the first proof of concept. [Aaed] shortly upgrades to steel cable, and finds out that steel fatigues and snaps after a few hours. He settles on Dyneema DM-20, a flexible yet non-stretching synthetic rope.

Before it’s all over, he got a five-bar linkage plotting with a pencil on the table and a quadriped leg jumping up and down on the table — to failure. All in all, it points to a great future, and we can’t wait to see the dog-bot that’s going to come out of this.

There’s nothing secret about using capstan drives, but we often wonder why we don’t see cable-powered robotics used more in the hacker world. [Aaed] makes the case that it pairs better with 3D printing than gears, where the surface irregularities really bind. If you want to get a jumpstart, the test fixture that he’s using is available on GitHub.

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Hype Robot Rocks Out With The Twitch Chat

Have you ever wished for an automaton that can get the party started, raise the roof, and all that? You’ll want to meet [DJ Pfeif]’s Flippin Rhobot, then. He’s a hype bot from the world of Twitch streaming, and he apparently knows how to party.

Flippin Rhobot is controlled by an ESP32 that listens into the chat on [DJ Pfeif]’s stream. He’s got a vaguely humanoid form, and he can rotate on the spot and wave his arms in the air courtesy of a few servos. He’s also got a little computer terminal that displays the show’s “Hack the Planet” logo when he turns to face the screen. His body also features some addressable LEDs that flash and dance on command.

[DJ Pfeif] does a good job of explaining the project, and includes the code that laces everything together. Interfacing with Twitch chat can be fun, and we’ve featured a guide on doing just that before, too.

If you’re building your own roboticized hype machine, don’t hesitate to let us know. Otherwise, consider musing on the very idea of humanoid robots as a whole!

Twelve pink tentacles are wrapped around a small, green succulent plant. The leaves seem relatively undisturbed. They are dangling from brass and white plastic pressure fittings attached to a brass circle.

Tentacle Robot Wants To Hold You Gently

Human hands are remarkable pieces of machinery, so it’s no wonder many robots are designed after their creators. The amount of computation required to properly attenuate the grip strength and position of a hand is no joke though, so what if you took a tentacular approach to grabbing things instead?

Inspired by ocean creatures, researchers found that by using a set of pneumatically-controlled tentacles, they could grasp irregular objects reliably and gently without having to faff about with machine learning or oodles of sensors. The tentacles can wrap around the object itself or intertwine with each other to encase parts of an object in its gentle grasp.

The basic component of the device is 12 sections “slender elastomeric filament” which dangle at gauge pressure, but begin to curl as pressure is applied up to 172 kPa. All of the 300 mm long segments run on the same pressure source and are the same size, but adding multiple sized filaments or pressure sources might be useful for certain applications.

We wonder how it would do feeding a fire or loading a LEGO train with candy? We also have covered how to build mechanical tentacles and soft robots, if that’s more your thing.

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