BrachioGraph

I recommend a Brachiograph build. It will introduce you to some fundamentals of PWM and inverse kinematics. It is well documented but not cookie-cutter. Using a Raspberry Pi will give you more direct access to running the servos than the microcontroller experience. All the parts are infinitely reusable afterward if you don't want to keep it around. https://www.youtube.com/watch?v=u4Jh1daCl60 https://www.brachiograph.art/ https://github.com/evildmp/BrachioGraph Sample Supply List for $80 budget: Pi Zero with header $20: https://www.adafruit.com/product/6008 Power supply $9: https://www.adafruit.com/product/1995 SD Card $10: https://www.adafruit.com/product/1294 Three hobby servos $18: https://www.adafruit.com/product/169 Breadboard wires $5: https://www.adafruit.com/product/153 Breadboard $5: https://www.adafruit.com/product/

You have to think of this as an entire system. The arm is necessary but not sufficient. An "arm" could be as simple as small servos and popsicle sticks [0]. In the case of ALOHA, below is an outline of the basic components. * arms (aka follower arms) - effector (i.e. gripper) - sensors (i.e. cameras, depth sensors, specced Intel RealSense D405) - gravity compensation (so the relatively delicate servos aren't overloaded) * controller - runs Robot Operating System (ROS [1]) plus other software (i.e. arm, gripper interfaces [2]) - runs ALOHA model in inference to tell ROS what to do based on task and sensor input - trains ALOHA models using arm motion encoder and ACT: Action Chunking with Transformers [4] * leader arms - motion encoders (essentialy an arm in reverse that can be used by a human to telecon

Full details of the project, including all the code and documentation, are posted at https://www.brachiograph.art. This is my attempt to do something with the Raspberry Pis and cheap servo motors I've had hanging around that's both genuinely interesting and also as simple and cheap as possible. Robotics isn't my subject, but I wanted to make something. The total cost of hardware (excluding the clothes-peg, pencil and things you will find in a kitchen drawer) is €14. You could build the whole thing in about an hour, it's a fun thing to do with a child, and they love the fact that it's made from household materials. One thing I like about it is that it's all 'wrong' - you are not supposed to use servos or electronics like this, and it's not what a 'real' engineer would do - but it still works well enough to be fun. The cost and simplicity a

On GitHub: https://github.com/evildmp/BrachioGraph