Gigantic arms are not feasible because of how torque and leverage work.
As your arm gets longer, it has to get stronger, thus heavier, thus requiring larger motors, and anchored to the ground better. After a handful of meters, robot arms can’t hold themselves up, let alone carry a useful tool.
There are multiple meter long robot arms for lifting big things in factories but they are enormous, enormously expensive, and consume enormous power.
But here’s a delightful concept that sidesteps this, by making the arm weigh nothing:
As your arm gets longer, it has to get stronger, thus heavier, thus requiring larger motors, and anchored to the ground better. After a handful of meters, robot arms can’t hold themselves up, let alone carry a useful tool.
There are multiple meter long robot arms for lifting big things in factories but they are enormous, enormously expensive, and consume enormous power.
But here’s a delightful concept that sidesteps this, by making the arm weigh nothing:
https://youtu.be/INTHRNcyW9w