Gaze Upon The Swimming Mechanical Stingray, Made With LEGO

December 10, 2022 by Donald Papp 5 Comments

Stingrays have an elegant, undulating swimming motion that can be hypnotic. [Vimal Patel] re-created this harmony with his fantastic mechanical mechanical stingray using LEGO pieces and a LEGO Technics Power Functions motor. The motor is set in a clever arrangement that drives the motion remotely, so that it and electrical elements can stay dry.

The mechanical stingray sits at the end of a sort of rigid umbilical shaft. This shaft connects the moving parts to the electrical elements, which float safely on the surface. This leaves only the stingray itself with its complex linkages free to move in the water, while everything else stays above the waterline.

We’ve seen some impressive LEGO creations before, like this race car simulator and pneumatic engine, and the mechanical action in this stingray is no exception. Interested in making your own? The part list and build directions are available online, and you can see it in action in the video embedded below.

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The Robots Of Fukushima: Going Where No Human Has Gone Before (And Lived)

December 8, 2022 by Ryan Flowers 9 Comments

The idea of sending robots into conditions that humans would not survive is a very old concept. Robots don’t heed oxygen, food, or any other myriad of human requirements. They can also be treated as disposable, and they can also be radiation hardened, and they can physically fit into small spaces. And if you just happen to be the owner of a nuclear power plant that’s had multiple meltdowns, you need robots. A lot of them. And [Asianometry] has provided an excellent synopsis of the Robots of Fukushima in the video below the break.

Starting with robots developed for the Three Mile Island incident and then Chernobyl, [Asianometry] goes into the technology and even the politics behind getting robots on the scene, and the crossover between robots destined for space and war, and those destined for cleaning up after a meltdown.

The video goes further into the challenges of putting a robot into a high radiation environment. Also interesting is the state of readiness, or rather the lack thereof, that prompted further domestic innovation.

Obviously, cleaning up a melted down reactor requires highly specialized robots. What’s more, robots that worked on one reactor didn’t work on others, creating the need for yet more custom built machines. The video discusses each, and even touches on future robots that will be needed to fully decommission the Fukushima facility.

For another look at some of the early robots put to work, check out the post “The Fukushima Robot Diaries” which we published over a decade ago.

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Radial Vector Reducer Rotates At Really Relaxed Velocity

December 5, 2022 by Ryan Flowers 15 Comments

When [Michael Rechtin] learned about Radial Vector Reducers, the underlying research math made his head spin, albeit very slowly. Realizing that it’s essentially a cycloidal drive meshed with a planetary gear set, he got to work in CAD and, in seemingly no time, had a design to test. You can see the full results of his experiment in the video below the break. Or head on out to Thingiverse to download the model directly.

[Michael] explains that while there are elements of a cycloidal drive, itself a wonderfully clever gear reduction mechanism, the radial vector reducer actually has more bearing surfaces, and should be more durable as a result. Two cycloidal disks are driven by a planetary gear reduction for an even greater reduction, but they don’t even spin, they just cycle in a way that drives the outer shell, setting them further apart from standard cycloidal drives.

How would this 3D printed contraption hold up? To test this, [Michael] built a test jig with a NEMA 23 stepper providing the torque, and an absurd monster truck/front loader wheel — also printed — to provide traction in the grass and leaves of his back yard. He let it drive around its tether for nearly two weeks before disassembling it to check for wear. How’d it look? You’ll have to check the video to find out.

If you aren’t familiar with cycloidal drives, check out this fantastic explanation we featured. As for planetary drives, what better way to demonstrate it than by an ornamental planetary gear clock!

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This Is The Future Of Waste Management

December 4, 2022 by Dave Rowntree 13 Comments

Many of us have been asking for some time now “where are our robot servants?” We were promised this dream life of leisure and luxury, but we’re still waiting. Modern life is a very wasteful one, with items delivered to our doors with the click of a mouse, but the disposal of the packaging is still a manual affair. Wouldn’t it be great to be able to summon a robot to take the rubbish to the recycling, ideally have it fetch a beer at the same time? [James Bruton] shares this dream, and with his extensive robotics skillset, came up with the perfect solution; behold the Binbot 9000. (Video, embedded below the break)

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Ply Your Craft With Tubular Origami

December 1, 2022 by Abe Connelly 3 Comments

Researchers at the University of Pennsylvania have just published a paper on creating modular tubular origami machines which they call “Kinegami”, a portmanteau of “kinematic” and “origami”.

The idea behind their work is to create individual modules and joint mechanisms that can then be chained together to create a larger “serial” robot. Some example joints they propose are “prismatic” joints, allowing for linear motion, and “revolute” joints, which allow for rotational motion. One of the more exciting aspects of this process is that the joint mechanisms are origami-like structures which can be constructed from a single piece of flat material which is folded and glued together to make the module. Of particular interest is that the crease pattern for the origami-like folds can be laser cut into a material, cardboard or thin acrylic for example, which can be used as a guide to create the resulting structure. The crease patterns for the supporting structures, such as tubes or joints, can be taken from pre-formatted patterns or customized, so this method is very accessible to the hobbyist and could allow for a rich new method of rapid project prototyping.

The researchers go on to discuss how to create the composition of modules from a specification of joints and links (from a “Denavit-Hartenberg” specification) to attaching the junctures together while respecting curvature constraints (via the “Dubins path”). Their paper offers the gritty details along with the available accompanying source files. Origami hacking is a favorite subject of ours and we’ve featured articles on the use of origami in medical technology to creating inflatable actuators.

Video after the break!

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Simple Mod Lets Quadruped Robot Stand And Walk

November 19, 2022 by Donald Papp 9 Comments

When it comes to locomotion, robots don’t typically do more than one thing at a time. Walkers stick to walking, and rollers stick to rolling. However, this simple method of enabling a cheetah-style quadruped to stand and even walk a little is pretty clever.

With just a couple of rigid struts attached to the shins of the rear legs, it becomes possible for the robot to lever itself up into a stable standing position, and even shuffle around a bit. Not bad for a couple bolted-on bits with no moving parts!

The robot style will look pretty familiar to some of our readers. It does resemble Boston Dynamics’ Spot but it’s closer to the MIT Mini Cheetah, whose design and brushless motors made for eye-catching agility and speed. It has inspired not just countless DIY efforts, but also kits of parts from overseas sellers.

The image here should make it clear how it works, but take a moment to also watch the short video embedded just below the page break, and see the process in action from beginning to end.

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DIY Robotic Platform Aims To Solve Walking In VR

November 18, 2022 by Donald Papp 32 Comments

[Mark Dufour]’s TACO VR project is a sort of robotic platform that mimics an omnidirectional treadmill, and aims to provide a compact and easily transportable way to allow a user to walk naturally in VR.

Unenthusiastic about most solutions for allowing a user to walk in VR, [Mark] took a completely different approach. The result is a robotic platform that fits inside a small area whose sides fold up for transport; when packed up, it resembles a taco. When deployed, the idea is to have two disc-like platforms always stay under a user’s feet, keeping the user in one place while they otherwise walk normally.

It’s an ambitious project, but [Mark] is up to the task and the project’s GitHub respository has everything needed to stay up to date, or get involved yourself. The hardware is mainly focused on functionality right now; certainly a fall or stumble while using the prototype looks like it would be uncomfortable at the very best, but the idea is innovative. Continue reading “DIY Robotic Platform Aims To Solve Walking In VR” →