mrogivue

This should be [sudo apt-get update] (no 's')

Adjust the potentiometers on the driver boards

5V, but they run ok on 12V

USB issues. Check the Arduino forums

Isn't that what they're supposed to do?

With my firmware, they move all at the same time until they hit the endstop. Then one by one does the fine adjustment.

It depends on your DVD motor. You might have to have to adjust each one individually. Basically move the motor 10mm and measure how much it actually moved and adjust accordingly. Good luck!