[Christina Ernst] executed a fantastic idea just in time for Halloween: her very own Remy the rat (from the 2007 film Ratatouille). Just like in the film Remy perches on her head and appears to guide her movements by pulling on hair as though operating a marionette. It’s a great effect, and we love the hard headband used to anchor everything, which also offers a handy way to route the necessary wires.
Behind Remy are hidden two sub-micro servos, one for each arm. [Christina] simply ties locks of her hair to Remy’s hands, and lets the servos do the rest. Part of what makes the effect work so well is that Remy is eye-catching, and the relatively small movements of Remy’s hands are magnified and made more visible in the process of moving the locks of hair.
Originally Remy’s movements were random, but [Christina] added an MPU6050 accelerometer board to measure vertical movements of her own arm. She uses that sensor data to make Remy’s motions reflect her own. The MPU6050 is economical and easy to work with, readily available on breakout boards from countless overseas sellers, and we’ve seen it show up in all kinds of projects such as this tiny DIY drone and self-balancing cube.
Want to make your own Remy, or put your own spin on the idea? The 3D models and code are all on GitHub and if you want to see more of it in action, [Christina] posts videos of her work on TikTok and Instagram.
[via CBC]
That is quite effective and hard to beat as a frivolous fun project.
I think it would be perhaps more impressive and effective if the rat was a simple passive mechanical system – perhaps Bowden cables or pneumatic and soft robotic type systems to transfer some of her movements into the rat. With her long hair hiding the link between whatever body worn actuator power them and rat’s would be fairly easy, probably give greater flexibility of motion and more natural movements too. Almost certainly operate quieter than the motor as well, which is always a plus. Much tougher project though, I think I’d go pneumatic soft robotics myself probably use a casting wax for a resin printer to make the fine and detailed internal structures maybe even the whole mould and use a soft 2 part silicone (cure inhibition between the two may be an issue). But that is just an idea I’ve wanted to try for a long while for other projects and not got even close to getting around to.
Awesome…now put a randomizer on which side he leads you…spend the night going where the rat takes you. :)
Rat movement is already randomized, with random intervals too.
Ah yes…in the one without the accelerometer it is.
I think I’ve seen this before… https://www.youtube.com/watch?v=xAZnZKKy2OI
He serves the bagel! Catch him!
Brilliant project – would be really eye catching. The snack dress I like to see more video about. (See TikTok)
I wish there was a bit more information, like the wiring it took me quite a while the accelerometer was on her wrists as all the videos show random movement.
And it’s not quite clear to me what causes Remy’s arms to jump back up if it’s the wire in the shoulders how does that work?
If you look at the github repo there are 2 versions of the code. One is randomized with no accelerometer and the other does not have the random components but has the accelerometer.
The servos connected to strings move the arms.
Models could use a bit of revision (especially the arms) to make it more printable..and possibly to hide components better but it certainly is a great start.