[FrankJ]

Wire nuts may not be your favorite connector, but. They are available products UL listed for both stranded & solid wire. I have seen them used routinely on equipment that vibrates a lot more than a FRC robot ever will. You can tape them after they are made up if you are paranoid. The connection properly done will at last the life of the robot.

As in all things you need to use the right size for the number & size of wire.