More than 30 years ago, Nintendo’s R.O.B graced toy shelves, helping usher in an age of video games that is here to stay. For the few of us lucky to own one of these relics, we’ll find that R.O.B’s internal mechanisms that drive the arms and neck movements are just begging to be modified. That’s exactly what [Kenny Storm] did, installing a few continuous-rotation servos to give R.O.B a new mobile life of its own.
The original R.O.B featured a surprisingly intricate gearbox configuration embedded inside the shoulders for both up-and-down shoulder movement and hand-pinching. (For a more detailed investigation on the internals of the original hardware, have a look at this teardown.) This hack is sparsely documented, but from what we can gather, the mobile R.O.B uses all three existing degrees of freedom that the original supported while furthermore adding mobility with continuous rotation servos.
Glancing at the dates from this forum post, this find is almost 8 years old. Age is never a dealbreaker here, though, as the sheer quaintness of this hack will surely stand the test of time. Watching R.O.B take up a presence with mobility on this desk hearkens back to our childhood mysticism of unboxing this companion with our Nintendo when we were children. Finally (shameless plug!), if you’re just as excited as the author at the chance of seeing R.O.B back on your shelf with at-home-manufacturing techniques, have a go at printing my 1:1 scale R.O.B head replica.
Continue reading “R.O.B. Gets a Proper RC Resurrection”
Laser cutters are becoming more garage-accessible with overseas imports, but plenty of us still need to drop in on the college campus or makerspace to get our cuts. Having a laser onsite is a nice touch, but having a rotary axis is almost unheard of. These nifty add-ons enable your laser to cut and engrave radially symmetric parts. Their pricetags usually fall in the hundred-to-thousand dollar price range, so while that might stop us there’s nothing holding us back from building our own!
That’s exactly what both [Cesar] and [Russ] did with two homebrew designs built from scraps, and the results look comparable to the professional default. The design itself is simple, yet dead clever. The carriage straps directly onto the x-axis such that its motion is rigidly connected to it. The wheels on the bottom play a dual role. First, they let the carriage slide smoothly with the y-axis motion. They also support the object-to-be-engraved and convert the wheel rotation from the y-axis movement into rotation of the object. There’s one drawback here in that the diameter of the object-to-be-engraved affects the angle of rotation, but we’ve never been ashamed to do a little work with θ = s/r.
[Cesar] gets the credit for putting this hack out for the world to see, but [Russ] also get’s a big thanks for putting out a downloadable file of his carriage. It’s a testament to how sharing a thought can inspire us to iterate on better designs that they world can enjoy.
Rolling fourth-axes aren’t anything new on these pages, but they’re certainly rare! If your hungry for more rolling axis goodness, have a look at [Perry’s] router modifications.
Continue reading “Laser Rotary Adapter Gets You Rolling”
Here on Hackaday, we’re generally designers of hacks that live in the real world. Nevertheless, I’m convinced that some of the most interesting feats are at the mercy of what’s possible in software, not hardware. Without the right software, no 3D printer could print and no quadcopter could fly. The source code that drives these machines may take months of refinement to flesh out their structure. In a nutshell, these software packages are complicated, and they don’t happen overnight.
So how do they happen; better yet: how could we make that happen? How do we write software that’s flexible enough to coexist peacefully on all sorts of hardware variations?
What separates the big open-source software projects like ROS, LinuxCNC, and Multiwii from the occastional hackathon code are the underlying principles that govern how they’re written. In object-oriented programming, these principles are called design patterns. In the next couple posts, I’m going to crack the lid on a few of these. What’s more, I’ll package them into real-world examples so that we can see these patterns interact with real hardware. The next time you pop open the source code for a big open source hardware project, I hope you can tease out some of these patterns in the code. Better yet, I hope you carry these patterns into your next robot and machine project. Let’s get started.
For readability, all of the examples run in Python3. The snippets below are truncated for brevity, but the real examples in the repository will work if you’ve got a similar hardware setup.
Continue reading “Software Design Patterns for Real Hardware”
FDM 3D prints might be coming home this holiday as seasonal ornaments, but with a few tweaks, they may even stand up to the tests of the real world as functional prototypes. Heat-Set inserts are one such tweak that we can drop into a print, and [Kurt] spares no expense at laying down a guide to get us comfortable with these parts. Here, he’s created a drill press adapter and modified his soldering iron to form an insert jig to start melting these parts into his next project.
Heat-set inserts grant us proper screw threads in any thermoplastic. Simply heat them up, stake them into your part, let cool, and: voila–a screw thread that’s firmly embedded into our part. We can load these inserts with clumsy hand tools, but why fumble and bumble with a hot soldering iron when we can adapt our drill press to do most of the tricky fixturing for us? That’s exactly what [Kurt] did here. With a 3D-printed adaptor, he’s letting his drill press (turned off!) hold the soldering iron so that he can use the lever to slowly stake the part into the 3D print. Finally, for no additional charge, [Kurt] turned down his soldering tip to mate cleanly into the insert for a cleaner removal.
We’ve seen adapters like this one before, but it’s never too often to get a reminder of the structural bonus that these parts can add to our 3D prints.
Armed with an overseas CNC machine retrofitted with custom electronics, [Eric] has taken to wowing us with his suite of home-fabricated slingshots. In a more recent stint, he’s just polished off his Enzo Carbon Fiber Hydra Slingshot, complete with a build log that’s loaded with step-by-step insights.
[Eric’s] build started with a few carbon panels laying dormant in his shop for half a year. After epoxying two of these boards together for added thickness, he machines them down with his retrofitted Sable-2015 “Lunchbox CNC.” His final product accepts a few press-fit inserts, a few more machined ABS edge pieces for aesthetics, and behold: a professional slingshot that’s about as beautiful as it is dangerous.
Although the Sable-2015 CNC machine (made in Taiwan) isn’t a frequent flyer here on Hackaday, it had dozens of proud owners on a few hobby machinist forums that will rave about its wares. We’re proud to see a small-but-sturdy machine that we could carry one-handed be put to such delicate work.
[Eric] could’ve had us with his Lunchbox CNC Instructable, but he’s taken his craftsmanship to the next level by leveraging his homebrew tools and living the bootstrapped-machine-shop narrative. Slingshots don’t land here too often on these pages, but if you’re hungry for another machine monster, have a look at [Dennis the Menace’s] Triple Threat.
Here on Hackaday, too often do we turn our heads and gaze at the novelty of 3D printing functional devices. It’s easy to forget that other techniques for assembling functional prototypes exist. Here, [Reuben] nails the aspect of functional prototyping with the laser cutter with a real-world application: a roll-pitch friction differential drive built from just off-the shelf and laser-cut parts!
The centerpiece is held together with friction, where both the order of assembly and the slight wedged edge made from the laser cutter kerf keeps the components from falling apart. Pulleys transfer motion from the would-be motor mounts, where the belts are actually tensioned with a roller bearing mechanism that’s pushed into position. Finally, the friction drive itself is made from roller-blade wheels, where the torque transferred to the plate is driven by just how tightly the top screw is tightened onto the wheels. We’d say that [Reuben] is pushing boundaries with this build–but that’s not true. Rather, he’s using a series of repeatable motifs together to assemble a both beautiful and complex working mechanism.
This design is an old-school wonder from 2012 uncovered from a former Stanford course. The legendary CS235 aimed to teach “unmechanically-minded” roboticists how to build a host of mechanisms in the same spirit as MIT’s How-to-make-almost-Anything class. While CS235 doesn’t exist anymore, don’t fret. [Reuben] kindly posted his best lectures online for the world to enjoy.
Continue reading “Friction Differential Drive is a Laser-Cut Triumph”
Researchers have been playing around with various oddball forms of robot locomotion; surely, we’ve seen it all, haven’t we? Not so! Lucky for us, [researchers at Stanford] are now showing us a new way for robots to literally extrude themselves from point A to point B.
This robot’s particular motion for mechanism involves unwinding itself inside out. From a stationary base, a reel caches meters of the robot’s uninflated polyethylene body, which it deploys by pressurizing. Researchers can make full 3D turns by varying the amount of inflated air in outer control chambers. What’s more, they can place end effectors or even payloads at the tip of the growing end with their position held in place by a cable.
As we can imagine, any robot that can squeeze its way up to 72 meters long can have dozens of applications, and the folks at Stanford have explored a host of nooks and crannies of this space. Along the way, they deploy complex antenna shapes into the air, deliver small payloads, extinguish fires, and squeeze through all sorts of uninviting places such as flytraps and even a bed of nails. We’ve placed a video below the break, but have a look at Ars Technica’s full video suite to get a sense of the sheer variety of applications that they imparted upon their new creation.
Biomimetics tends to get us to cry “gecko feet” or “snake robots” without thinking too hard. But these forms of locomotion that come to mind all seem to derive from the animal kingdom. One key element of this soft robot is that its stationary base and vine-like locomotion both have its roots in the plant kingdom. It’s a testament to just how unexplored this realm may be, and that researchers and robots will continue to develop new ways of artificially “getting around” for years to come.
Thanks for the tip, [Jacob!]
Continue reading “Researchers Squeeze Out a New Breed of Robot Locomotion”