The time is from the moment the keypress is registered on the computer, to when the last face is flipped. It includes image capture and computation time, as well as actually moving the cube. The motion time is ~335 ms, and the remaining time image acquisition and computation. For reference, the current world record is/was 0.637 seconds.
The machine can definitely go faster, but the tuning process is really time-consuming since debugging needs to be done with the high-speed camera, and mistakes often break the cube or blow up FETs. Looking at the high-speed video, each 90 degree move takes ~10 ms, but the machine is actually only doing a move every ~15 ms. For the time being, Jared and I have both lost interest in playing the tuning game, but we might come back to it eventually and shave off another 100 ms or so.
The contraption is built from:
6 Kollmorgen ServoDisc U9-series motors. 2 were taken from my old robot arm project, the rest were found pretty cheaply on ebay. Each motor has a US Digital optical encoder on the back, also purchased for a bargain on ebay.
6 custom motor drivers.
2 PlayStation Eye cameras
1 Rubik’s Cube. One of the cheapest available
Previously a machine solved the Rubiks cube in 0.637 seconds.
The human world record is 4.59 seconds.