Has anyone ever done stop motion with animatronics? It seems like that would be an ideal solution to doing stop-motion really fast.
Yes, not necessarily faster at all!
If the animatronic has pre-determined moves, then it's really just automata with a stepper motor. I will depend on complexity of motion, repetition of action, length of labour (and budget...) as to whether it's worth bringing in computer controls.
There's a mix of hand-controlled, puppeteered, and automated in "Kubo"...
A few years ago, DisneyResearch unveiled new automata software, improving user-accessibility and improving the quality of motion:
There's similar software on the internet, but not Disney's per se. They did release their white papers though, which aren't light reading.
I think the allure of animatronics vs automata is the prospect of recording a unique hand-puppeteered performance for playback, or creating a sequence from an existing library of motions. Perhaps there's a market for animatronic motion library assets.
The automata software has the potential of being able to rapidly generate different characters with the same motion, or the same character with different motions. I imagine it would integrate well with easy control parameters such as BioMotionLab's software. I hope these developments continue and 3D printing gets cheaper...