A lot of projects require linear motion, but not all of them require high-accuracy linear slides and expensive ball screws. When just a little shove for a door or the ability to pop something up out of an enclosure is all you need, finding just the right actuator can be a chore.
Unless someone has done the work for you, of course. That’s what [Ali] from PotentPrintables did with these 3D-printed linear actuators. It’s a simple rack-and-pinion design that’s suitable for light loads and comes in two sizes, supporting both the 9-g micro servos and the larger, more powerful version. Each design has a pinion that has to be glued to a servo horn, and a selection of rack lengths to suit your needs. The printed parts are nothing fancy, but seem to have material in the right places to bear the loads these actuators will encounter. [Ali] has included parts lists and build instructions in with the STL files, as well as sample Arduino code to get you started. The video below shows the actuators in action.
We’re heartened to learn that [Ali] was at least partly inspired to undertake this design by a previous Hackaday post. And we’re glad he decided to share his version; it might save us a few steps on our next build.
Granted, you may not have a well-stocked metal shop or a team of oxen up by the lake wherever you live, but there are certainly details in the video that will survive in translation. Basically, the team took the axle off of a junked car, attached it to a pole in the middle of the lake, made a large wooden drive wheel, and wrapped an infinite length of rope around it.
[Charles] from [Mad Cow] wrote us that there was about a 10:1 ratio between the drive wheel and the arms of the people-flinger. So if the cattle were pulling at 3 km/h, the human angular velocity was a brisk 30 km/h! Then it’s just a matter of convincing a team of cows, or a team of soccer players (?), to put their backs into it.
The [Mad Cow] crew seems to have more than their fair share of engineering dangerous fun up at their summer hideaway: check out their human crossbow that we featured a few years back.
The engineers and product designers at [moovel lab] have created the Open Data Cam – an AI camera platform that can identify and count objects as they move through its field of view – along with an open source guide for making your own.
Step one: get out your ruler and utility knife. In this world of ubiquitous 3D-printers they’ve taken a decidedly low-tech approach to the project’s enclosure: a cut, folded, and zip-tied plastic box, with a cardboard frame inside to hold the electronic bits. It’s “splash proof” and certainly cheap to make, but we’re a little worried about cooling and physical protection for the electronics inside, as they’re not exactly cheap and rugged components.
So what’s inside? An Nvidia Jetson TX2 board, a LiPo battery with some charging circuitry, and a standard webcam. The special sauce, however, is the software, which is available on GitHub. [Moovel lab]’s engineers have put together a nice-looking wifi-accessible mobile UI for marking the areas where you’d like the software to identify and tally objects. The actual object detection and identification tasks are performed by the speedy YOLO neural network, a task the Nvidia board’s GPU is of course well suited for.
As the Open Data Cam’s unblinking glass eye gazes upon our urban environments, it will log its observations in an ancient and mysterious language: CSV. It’s up to you, human, to interpret this information and use it for good.
A summary video and build time lapse are embedded after the break.
Overseas factories can be sort of a mythical topic. News articles remind us that Flex (née Flextronics) employs nearly 200 thousand employees worldwide or that Foxconn is up to nearly a million. It must take an Apple-level of insider knowledge and capital to organize such a behemoth workforce, certainly something well past the level of cottage hardware manufacturing. And the manufacturing floor itself must be a temple to bead blasted aluminum and 20 axis robotic arms gleefully tossing products together. Right?
Well… the reality is a little different. The special sauce turns out to be people who are well trained for the task at hand and it doesn’t require a $1,000,000,000,000 market cap to get there.
[Adam leeb] was recently overseas to help out with the production ramp for one of his products and took a set of fantastic videos that walk us through an archetypical asian factory.
I’ve been to several factories and for me the weirdest part of the archetype is the soul crushing windowless conference room which is where every tour begins. Check out this one on the left. If you ever find yourself in a factory you will also find a room like this. It will have weird snacks and bottles of water and a shiny wood-esque table. It will be your home for many, many more hours than you ever dreamed. It’s actually possible there’s just one conference room in the universe and in the slice of spacetime where you visit it happens to be in your factory.
Ok, less metaphysics. It’s amazing to watch the myriad steps and people involved in taking one product from zero to retail-ready. [adam] gives us a well narrated overview of the steps to go from a single bare board to the fully assembled product. From The Conference Room he travels to The Floor and walks us through rows of operators performing their various tasks. If you’ve been reading for a while you will recognize the pick and place machines, the ovens, and the pogo pin test fixtures. But it’s a treat to go beyond that to see the physical product that houses the boards come together as well.
Check out [adam]’s videos after the break. The first deals with the assembly and test of his product, and the second covers the assembly of the circuit boards inside which is broadly referred to as SMT. Watching the second video you may notice the funny (and typical) contrast between the extremely automated SMT process and everything else.
We all know how important it is to achieve balance in life, or at least so the self-help industry tells us. How exactly to achieve balance is generally left as an exercise to the individual, however, with varying results. But what about our machines? Will there come a day when artificial intelligences and their robotic bodies become so stressed that they too will search for an elusive and ill-defined sense of balance?
We kid, but only a little; who knows what the future field of machine psychology will discover? Until then, this kinetic sculpture that achieves literal balance might hold lessons for human and machine alike. Dubbed In Medio Stat Virtus, or “In the middle stands virtue,” [Astrid Kraniger]’s kinetic sculpture explores how a simple system can find a stable equilibrium with machine learning. The task seems easy: keep a ball centered on a track suspended by two cables. The length of the cables is varied by stepper motors, while the position of the ball is detected by the difference in weight between the two cables using load cells scavenged from luggage scales. The motors raise and lower each side to even out the forces on each, eventually achieving balance.
The twist here is that rather than a simple PID loop or another control algorithm, [Astrid] chose to apply machine learning to the problem using the Q-Behave library. The system detects when the difference between the two weights is decreasing and “rewards” the algorithm so that it learns what is required of it. The result is a system that gently settles into equilibrium. Check out the video below; it’s strangely soothing.
Chances are good that a fair number of us have been roped into “one of those” projects before. You know the type: vague specs, limited budget, and of course they need it yesterday. But you know 3D-printers and Raspberduinos and whatnot; surely you can wizard something together quickly. Pretty please?
He might not have been quite that constrained, but when [Sean Hodgins] got tapped to help a friend out with an unusual project, rapid prototyping skills helped him create this GPS-enabled faux-walkie talkie audio player. It’s an unusual device with an unusual purpose: a comedic walking tour of Vancouver “haunted houses” where his friend’s funny ghost stories are prompted by location. The hardware to support this is based around [Sean]’s useful HCC module, an Arduino-compatible development board. With a GPS module for localization and a VS1053 codec, SD card reader, and a small power amp for the audio end, the device can recognize when the user is within 50 meters of a location and play the right audio clip. The housing is a 3D-printed replica of an old toy walkie-talkie, complete with non-functional rubber ducky antenna.
Setting a bottle adrift with a message in it is, by most measures, an act of desperation. The sea regularly swats mighty ships to their doom, so what chance would a tiny glass bottle have bobbing along the surface, subject as it is to wind, waves, and current? Little to none, it would seem, unless you skew the odds a bit with a wave-powered undersea glider to the help the bottle along.
Before anyone gets too worked up about this, [Rulof Maker]’s “Sea Glider” is about a low-tech as a device with moving parts can be. This craft, built from a scrap of teak and a busted wooden ruler, is something that could be assembled in a few hours from whatever you have on hand, even if you’re marooned on an uncharted desert isle. The body of the craft sprouts a set of horizontal planes that can swivel up and down independently. The key to providing a modicum of thrust is that each plane is limited to a 90° swing by stop blocks above and below the pivot. The weighted glider, tethered to the bottle, bobs up and down below the waves, flapping the planes and providing a tiny bit of thrust.
Was it enough to propel the bottle any great distance? We won’t ruin the surprise, but we will say that [Rulof]’s essentially zero-cost build appears to have improved the message in a bottle bandwidth at least somewhat. It’s not a Hackaday Prize-winning robotic sea glider, but it’s a neat hack nonetheless.