Hi, knfenimore, I'm an engineer who used to work for CAE and several other flight simulator manufacturers.

It’s called 6 degrees of Freedom, not because there are 6 hydraulic rams supporting the simulator, but because the simulator can move on 6 axes: Pitch, Yaw, Roll, Front-Back, Left-Right & up & down. These are the degrees (or axes) of freedom. Many much older simulators were only 3 DOF: Pitch, Yaw, Roll.

P.S. Have you even seen what happens when one of the hydraulic pipes comes loose from the RAM under pressure? I have, and you don't want to be anywhere near it!!