Usually at Hackaday we like to post projects that are of interest because of their complexity. That’s especially true for robots — the more motors and sensors the better. But, occasionally we come across a project that’s beautiful because of its simplicity. That’s the case with [Max.K’s] ZeroBot, recently posted over on Hackaday.io.
When you’re running a Kickstarter for a robotic arm, you had better be ready to prove how repeatable and accurate it is. [Andrew] has done just that by laser engraving 400 wooden coasters with Evezor, his SCARA arm that runs on a Raspberry Pi computer with stepper control handled by a Smoothieboard.
Evezor is quite an amazing project: a general purpose arm which can do everything from routing circuit boards to welding given the right end-effectors. If this sounds familiar, that’s because [Andrew] gave a talk about Evezor at Hackaday’s Unconference in Chicago,
One of the rewards for the Evezor Kickstarter is a simple wooden coaster. [Anderw] cut each of the wooden squares out using a table saw. He then made stacks and set to programming Evezor. The 400 coasters were each picked up and dropped into a fixture. Evezor then used a small diode laser to engrave its own logo along with an individual number. The engraved coasters were then stacked in a neat output pile.
After the programming and setup were complete, [Andrew] hit go and left the building. He did keep an eye on Evezor though. A baby monitor captured the action in low resolution. Two DSLR cameras also snapped photos of each coaster being engraved. The resulting time-lapse video can be found after the break.
You can’t deny the appeal of gardening. Whether it’s a productive patch of vegetables or a flower bed to delight the senses, the effort put into gardening is amply rewarded. Nobody seems to like the weeding, though — well, almost nobody; I find it quite relaxing. But if you’re not willing to get down and dirty with the weeds, you might consider deploying a weed-eating garden robot to do the job for you.
Dubbed the Tertill, and still very much a prototype, the garden robot is the brainchild of some former iRobot employees. That’s a pretty solid pedigree, and you can see the Roomba-esque navigation scheme in action — when it bumps into something it turns away, eventually covering the whole garden. Weed discrimination is dead simple: short plants bad, tall plants good. Seedlings are protected by a collar until they’re big enough not to get zapped by the solar-powered robot’s line trimmer.
It’s a pretty good idea, but the devil will be in the details. Will it be able to tend the understory of gardens where weeds tend to gather as the plants get taller? Can it handle steep-sided raised beds or deeply mulched gardens? Perhaps there are lessons to be learned from this Australian weed-bot.
A self-balancing robot is a great way to get introduced to control theory and robotics in general. The ability for a robot to sense its position and its current set of circumstances and then to make a proportional response to accomplish its goal is key to all robotics. While hobby robots might use cheap servos or brushed motors, for any more advanced balancing robot you might want to reach for a brushless DC motor and a new fully open-source controller.
The main problem with brushless DC motors is that they don’t perform very well at low velocities. To combat this downside, there are a large number of specialized controllers on the market that can help mitigate their behavior. Until now, all of these controllers have been locked down and proprietary. SmoothControl is looking to create a fully open source design for these motors, and they look like they have a pretty good start. The controller is designed to run on the ubiquitous ATmega32U4 with an open source 3-phase driver board. They are currently using these boards with two specific motors but plan to also support more motors as the project grows.
We’ve seen projects before that detail why brushless motors are difficult to deal with, so an open source driver for brushless DC motors that does the work for us seems appealing. There are lots of applications for brushless DC motors outside of robots where a controller like this could be useful as well, such as driving an airplane’s propeller.
We first heard about [Robert Stephenson]’s robotic baby dinosaur a few years ago, and recently he made some upgrades.
Roboceratops V2 uses 10 servos in the jaw, neck, tail, and front and back legs with 16 degrees of freedom—the two front legs each got an additional degree of freedom in the upgrade. [Robert] is currently in the process of swapping out the Hitec HS645 MGs for higher-torque New Power XLDs.
The older version had aluminum legs covered with upholstery foam, but [Robert] has refined the design. The head, body, and legs are made from laser-cut MDF sanded to give a more natural, bone-like rounding. Finally, to better make use of the new servos [Robert] rewrote the gait engine, giving Robosaurus a more natural motion as it adjusts its center of gravity with each step.
So, for the next version are we all on board for simulated skin?
You’d think pool should be an easy game for a robot to play, right? It’s all math — geometry to figure out the angles and basic physics to deal with how much force is needed to move the balls. On top of that, it’s constrained to just two dimensions, so it should be a breeze.
Any pool player will tell you there’s much, much more to the game in real life, but still, a robot to play pool against would be a neat trick. As a move toward that goal, [BVarv] wisely decided on a miniature mockup of a pool-playing robot, and in the process reinvented the pool table itself. Realizing that a tracked or wheeled robot would have a tough time maneuvering around the base of a traditional pool table, his model pool table is a legless design that looks like something from IKEA. But the pedestal support allows the robot to be attached to the table and swing around in a full circle, and this allowed him to work through the kinematics as shown in the charming stop-action video below.
[BVarv] has gotten as far as motion control on the swing axis, as well as on the arms that will eventually hold the cue. He plans overhead image analysis for identifying shots, and of course there’s the whole making it full-size thing to do. We’d love to play a game or two against a bot, so we hope he gets there. In the meantime, how about a little robo-air hockey?
The idea of purpose is one of great importance to many sentient beings; one can only imagine the philosophical terror experienced by a robot designed solely to pass butter. Perhaps wishing to create a robot with more reason to exist, [Micah “Chewy” Leibowitz] decided to build this battlebot armed with a flamethrower, named Flamewar.
In the video, we see it rather successfully facing off against a robot named T800, at least in the early part of the fight. T800 is armed with a spinning weapon, and while it is able to deliver a heavy thump thanks to stored kinetic energy, more often than not T800 seems to knock itself over rather than do any serious damage to Flamewar. Flamewar is repeatedly able to fire its primary weapon, as the flamethrower is built into its arms, far above the reach of T800’s armament. We won’t spoil the ending of the fight. Video below the break.
The robot was built by [Micah] who competes with [Team Tiki], who have documented some of their past builds online. We would like to see some footage of Flamewar actually passing some butter, though. The bout was a part of Robogames 2017, and we’re impressed that such things like flamethrowers are allowed in the rules. Obviously safety is a paramount concern of these events, so it’s awesome to see they’ve found a way to make things work.
We love seeing combat robots here at Hackaday. If you’re thinking about getting started yourself, why not get started with an ant-weight bot to cut your teeth?