Robots of the entertainment industry are given life by character animation, where the goal is to emotionally connect with the audience to tell a story. In comparison, real-world robot movement design focus more on managing physical limitations like sensor accuracy and power management. Tools for robot control are thus more likely to resemble engineering control consoles and not artistic character animation tools. When the goal is to build expressive physical robots, we’ll need tools like ROBiTS project to bridge the two worlds.
As an exhibitor at Maker Faire Bay Area 2019, this group showed off their first demo: a plugin to Autodesk Maya that translate joint movements into digital pulses controlling standard RC servos. Maya can import the same STL files fed to 3D printers, easily creating a digital representation of a robot. Animators skilled in Maya can then use all the tools they are familiar with, working in full context of a robot’s structure in the digital world. This will be a far more productive workflow for animation artists versus manipulating a long flat list of unintuitive slider controls or writing code by hand.
Of course, a virtual world offers some freedoms that are not available in the physical world. Real parts are not allowed to intersect, for one, and then there are other pesky physical limitations like momentum and center of gravity. Forgetting to account for them results in a robot that falls over! One of the follow-up projects on their to-do list is a bridge in the other direction: bringing physical world sensor like an IMU into digital representations in Maya.
It has never been easier to put a microcontroller and other electronics into a simple project, and that has tremendous learning potential. But when it comes to mechanical build elements like enclosures, frames, and connectors, things haven’t quite kept the same pace. It’s easier to source economical servos, motors, and microcontroller boards than it is to arrange for other robot parts that allow for cheap and accessible customization and experimentation.
That’s where [Andy Forest] comes in with the Laser Cut Cardboard Robot Construction Kit, which started at STEAMLabs, a non-profit community makerspace in Toronto. The design makes modular frames, enclosures, and basic hardware out of laser-cut corrugated cardboard. It’s an economical and effective method of creating the mechanical elements needed for creating robots and animatronics while still allowing easy customizing. The sheets have punch-out sections for plastic straws, chopstick axles, SG90 servo motors, and of course, anything that’s missing can be easily added with hot glue or cut out with a knife. In addition to the designs being open sourced, there is also an activity guide for educators that gives visual examples of different ways to use everything.
Cardboard makes a great prototyping material, but what makes the whole project sing is the way the designs allow for easy modification and play while being easy to source and produce.
Lip syncing for computer animated characters has long been simplified. You draw a set of lip shapes for vowels and other sounds your character makes and let the computer interpolate how to go from one shape to the next. But with physical, real world puppets, all those movements have to be done manually, frame-by-frame. Or do they?
He toyed around with a number of approaches for making the lip mechanism before coming up with one that worked the way he wanted. The lips are shaped using guitar wire soldered to other wires going to servos further back in the head. Altogether there are four servos for the lips and one more for the jaw. There isn’t much sideways movement but it does enough and lets the brain fill in the rest.
On the software side, he borrows heavily from the tools used for lip syncing computer-drawn characters. He created virtual versions of the five servo motors in Adobe Animate and manipulates them to define the different lip shapes. Animate then does the interpolation between the different shapes, producing the servo positions needed for each frame. He uses an AS3 script to send those positions off to an Arduino. An Arduino sketch then uses the Firmata library to receive the positions and move the servos. The result is entirely convincing as you can see in the trailer below. We’ve also included a video which summarizes the iterations he went through to get to the finished Billy Whiskers or just check out his detailed website.
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.
Ever dreamed of a real, life-sized Transformer in your garage? The Turkish startup Letrons now offers you exactly that: Their animatronic Autobot drives like a car, transforms like a Transformer, and supposedly fights off space threats with its built-in smoke machine and sound effects.
Letrons’s Transformer seems to be built upon a BMW E92 coupé chassis. According to the company, the beast is packed with powerful hydraulics and servo motors, allowing it to transform and move fast. Sensors all around the chassis give it some interactivity and prevent it from crushing innocent bystanders when in remote-control mode. Interestingly, its movable arms aren’t attached to the body, but to its extendable side-wings and feature hands with actuated wrists and fingers. The Autobot also can move its head, which pops right out of the hood.
Admittedly, Letrons must have spent a lot of time on the dark side of the moon and working in secrecy before they released footage of a working and polished prototype. It’s unclear if Letron’s Transformers will cooperate with the US military in solving armed conflicts, but they are certainly good for a show. Enjoy the video below!
Latvian artist [Krists Pudzens] just put on a show in Sweden and sent us the video of his amazing kinetic sculpture. (Embedded below.) We found an arty-theory writeup of another exhibition of his to share, but we had so many technical questions that we had to write him back asking for details. And boy, did he answer.
In the video, a couple of animatronic faces watch you as crab-like rope-climber bots inch upwards and red wings flap in the background. There’s a lot of brilliant mechanisms here, and aside from whatever it all means, we just like to watch machines go.
The details! Most of the pieces are plasma-cut steel or hand-cut-and-filed aluminum, and almost all of the motors are windshield wiper motors from old Russian KAMAZ and LADA cars. In another installation, the red wings (“Red Queens’ Race”) were installed in a public square and used to track the crowd, flapping faster as people moved more quickly by.
The robotic faces also use OpenCV to track you, and stare you down. One mask is vacuum-formed plastic, and the other is a copy in polyester resin and gelcoat. Here is a video of them on their own, and another of the development.
The twin rope-climbers, “Unbalanced Force”, just climb upwards at different paces. We were more than a little curious about what happens to the rope-climbers when they reach the top. [Krists] says the gallery staff grabs ladders and goes to fetch them. When he exhibited them in Poland on 20m ropes, they actually had to hire professional climbers. Life imitates art.
According to his Instructables profile, [bwebby] wants to make cool stuff in the special effects industry. We think he has a pretty good chance at it based on the animatronic hand he built.
The finger segments are made from copper pipe. They are connected to each other and to the sheet metal palm with tiny hinges and superglue. That stuff inside the finger segments is epoxy putty. It keeps the ends of the tendons made from bicycle gearing cable firmly attached to the fingertip segments, and provides a channel through the rest of the fingers. These cables run through 50mm aluminium tubes that are set in a sheet metal forearm, and they connect to high-torque servos mounted on a piece of MDF. [bwebby] used a Pololu Mini Maestro to control the servos using the board’s native USB interface and control software.
Watch [bwebby] run through some movements and try out the grip after the break. If you want to make an animatronic hand but aren’t ready for this type of undertaking, you could start with an approach closer to puppetry.