Taking Halloween To The Next Level With JARVIS

March 18, 2018 by Tom Nardi 11 Comments

As an avid “Haunt Hacker”, [Steve Koci] knows a thing or two about bringing high-tech to Halloween. Wanting to build a mobile robot that could accompany him to conventions as a demonstration of the sort of animatronic mechanisms and controls he uses, he came up with the idea of JARVIS. The original plan was to make a more traditional robot, but with the addition of an animated skull and some Steampunk-style embellishments, JARVIS is definitely the kind of thing you don’t want to run into on an October night.

Construction of JARVIS started in 2016, after [Steve] saw the Agent 390 tracked robot chassis from ServoCity. With the addition of extra wheels and a custom track, he converted the Agent 390 into a triangular track arrangement which he said he’s had his eye on since “Johnny 5” sported them back in Short Circuit.

There’s a dizzying array of electronics required to make JARVIS move and talk, not least of which is the “Banshee” prop controller. This device is made to simplify the construction of animatronic heads and provides not only organic-looking randomized movement but automatic jaw synchronization. Using a wireless audio connection, [Steve] is able to talk through a speaker mounted on the chest of the robot, while the skull automatically matches its mouth to his speech in real time. Combined with the GoPro in a two-axis gimbal, this allows JARVIS to function as a fairly robust telepresence platform. Much to the delight/horror of those it’s used on.

Getting JARVIS to move requires not only the two beefy motors and a dedicated controller supplied by the Agent 390 platform, but no less than thirteen servos for the head, arms, and grippers. There’s even a linear actuator used to tilt the skull up and down, presumably for terrifying people of various heights and ages. JARVIS even has a pair of Adafruit’s electronic eyes mounted in the skull, as if you thought you would be spared the horror of seeing glowing eyes following you in the dark.

To control all this hardware, [Steve] uses two RC transmitters in conjunction with a smartphone displaying the video feed coming from the GoPro. It takes some serious finger-gymnastics to get JARVIS doing its thing, which [Steve] says he’s still trying to master.

As many projects that have graced these pages can attest to, hackers seem to delight in coming up with new and exciting ways to terrify the young and old alike. Sometimes they can’t even wait until Halloween.

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Balloons And Bubbles Make For Kid-Friendly Robot Deathmatch

March 17, 2018 by Dan Maloney 6 Comments

Because nothing says “fun for kids” like barbed wire and hypodermic needles, here’s an interactive real-world game that everyone can enjoy. Think of it as a kinder, gentler version of Robot Wars, where the object of the game is to pop the balloon on the other player’s robot before yours get popped. Sounds simple, but the simple games are often the most engaging, and that sure seems to be the case here.

The current incarnation of “Bubble Blast” stems from a project [Niklas Roy] undertook for a festival in Tunisia in 2017. That first version used heavily hacked toy RC cars controlled with arcade joysticks. It was a big hit with the crowd, so [Niklas] built a second version for another festival, and incorporated lessons learned from version 1.0. The new robots are built from scratch from 3D-printed parts. Two motors drive each bot, with remote control provided by a 433-MHz transceiver module. The UI was greatly improved with big trackballs, also scratch built. The game field was expanded and extra obstacles were added, including a barbed wire border as a hazard to the festooned bots. And just for fun, [Niklas] added a bubble machine, also built from scratch.

The game looks like a ton of fun, and seems like one of those things you’ve got to shoo the adults away from so the kids can enjoy it too. But if you need more gore from your robot deathmatch than a limp balloon, here’s a tabletop robot war that’s sure to please.

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3D Printed Transmission Invented Again; This Time Continuously Variable

March 13, 2018 by Al Williams 26 Comments

We shouldn’t laugh, but we know the feeling very well. [Gear Down for What] invented a revolutionary transmission and fabricated it from scrap material when he was 16. Except he later found out the same design was the subject of a patent filed 14 years earlier. Dismayed he destroyed his prototype, but fast forward to today and he’s made a 3D model of a ratcheting continuously variable transmission. You can see a video of him explaining how it works below and put your own spin on the idea by grabbing the model from Thingiverse.

The model is just for demonstration purposes. We doubt it would wear well enough to use in practice but it’s great to get your hands on for a really intuitive understanding of the mechanism. Some modern automobiles use a continuously variable transmissions (CVT) and many recreational vehicles and motorcycles use them. Like any transmission, their job is to match the motor’s rotation to needed output torque and speed by offering different gearing ratios. Whereas a normal transmission provides a few fixed gears, a CVT changes seamlessly through a range of ratios.

Some of the design of the transmission is pretty tricky, like the cam adjustment. The video shows the rationale for how the design works and how it relates to tank steering (tank as in an Army tank; not like a gas tank). The model isn’t just plastic. It uses some screws and BBs, as well. However, if you have a 3D printer and wanted a good classroom demonstration, this is the ticket.

We’ve seen other geared variable transmissions for robots before. The planetary gears in the cam adjustment of this design are well understood. If you want to brush up your planetary knowledge, there’s no time like the present.

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Rubik’s Robot So Fast It Looks Like A Glitch In The Matrix

March 12, 2018 by Dan Maloney 27 Comments

From Ferraris to F-16s, some things just look fast. This Rubik’s Cube solving robot not only looks fast, it is fast: it solved a standard cube in 380 milliseconds. Blink during the video below and you’ll miss it — even on the high-speed we had trouble keeping track of the number of moves this solution took. It looked like about 20.

Beating the previous robot record of 637 milliseconds is just the icing on the cake of a very cool build undertaken by [Ben Katz]. He and his collaborator [Jared] put together a robot with a decidedly industrial look — aluminum extrusion chassis, six pancake servo motors with high-precision optical encoders, and polycarbonate panels for explosion containment which proved handy during development. The motors had to be modified to allow the encoders to be attached to the rear, and custom motor controllers were fabricated. [Jared] came up with a unique board to synchronize the six motors and prevent collisions between faces. Machine vision is provided by just two PlayStation Eye cameras; mounted at opposite corners of the enclosure, each camera can see three faces at a time. They had a little trouble distinguishing the red from the orange, which was solved with a Sharpie.

[Ben] and [Jared] think they can shave a few milliseconds here and there with tweaks, but even as it is, this is a great lesson in optimization and integration. We’ve covered Rubik’s robots before, like this two-motor slow and steady design and this six-motor build that solves a cube in less than a second.

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Glorious Body Of Tracked ‘Mad Mech’ Started As Cardboard

March 11, 2018 by Donald Papp 10 Comments

[Dickel] always liked tracked vehicles. Taking inspiration from the ‘Peacemaker’ tracked vehicle in Mad Max: Fury Road, he replicated it as the Mad Mech. The vehicle is remote-controlled and the tank treads are partly from a VEX robotics tank tread kit. Control is via a DIY wireless controller using an Arduino and NRF24L01 modules. The vehicle itself uses an Arduino UNO with an L298N motor driver. Power is from three Li-Po cells.

The real artistic work is in the body. [Dickel] used a papercraft tool called Pepakura (non-free software, but this Blender plugin is an alternative free approach) for the design to make the body out of thin cardboard. The cardboard design was then modified to make it match the body of the Peacemaker as much as possible. It was coated in fiberglass for strength, then the rest of the work was done with body filler and sanding for a smooth finish. After a few more details and a good paint job, it was ready to roll.

There’s a lot of great effort that went into this build, and [Dickel] shows his work and process on his project page and in the videos embedded below. The first video shows the finished Mad Mech being taken for some test drives. The second is a montage showing key parts of the build process.

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Marble Chooses Its Own Path

March 6, 2018 by Brian McEvoy 16 Comments

[Snille]’s motto is “If you can’t find it, make it and share it!” and we could not agree more. We wager that you won’t find his Roball sculpture on any shopping websites, so it follows that he made, and subsequently shared his dream. The sculpture has an undeniable elegance with black brackets holding brass rails all on top of a wooden platform painted white. He estimates this project took four-hundred hours to design and build and that is easy to believe.

Our first assumption was that there must be an Arduino reading the little red button which starts a sequence. A 3D-printed robot arm grasps a cat’s eye marble and randomly places it on a starting point where it invariably rolls to its ending point. The brains are actually a Pololu Mini Maestro 12-channel servo controller. The hack is using a non-uniform marble and an analog sensor at the pickup position to randomly select the next track.

If meticulously bending brass is your idea of a good time, he also has a video of a lengthier sculpture with less automation, but it’s bent brass porn. If marbles are more your speed, you know we love [Wintergatan] and his Incredible Marble Music Machine. If that doesn’t do it for you, you can eat it.

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The M1 NerfBot: When Prototypes Evolve

March 6, 2018 by James Hobson 7 Comments

What do you get when you cross a self-taught maker with an enthusiasm for all things Nerf? A mobile nerf gun platform capable of 15 darts per second. Obviously.

The M1 NerfBot built by [GrimSkippy] — posting in the ‘Let’s Make Robots’ community — is meant to be a constantly updating prototype as he progresses in his education. That being the case, the progress is evident; featuring two cameras — a webcam on the turret’s barrel, and another facing forward on the chassis, a trio of ultrasonic sensors, controlled by an Xbox 360 controller, and streaming video to a webpage hosted on the M1 itself, this is no mere beginner project.

Perhaps most compelling is how the M1 tracks its targets. The cameras send their feeds to the aforementioned webpage and — with a little reorganization — [GrimSkippy] accesses the the streams on an FPV headset-mounted smartphone. As he looks about, gyroscopic data from the phone is sent back to the M1, translating head movement into both turret and chassis cam movement. Check it out!

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