[M. Mellott]

Steve,

Per Wikipedia...Six degrees of freedom (6DoF) refers to the freedom of movement of a rigid body in three-dimensional space. Specifically, the body is free to change position as forward/backward, up/down, left/right translation in three perpendicular axes [X, Y, and Z], combined with changes in orientation through rotation about those same three perpendicular axes, often termed pitch, yaw, and roll.

Using your examples...a motor has one degree of freedom (rotation about the output axle), so it would be legal--going forwards or backwards is still rotation about one axis, i.e. positive/negative direction. However, as mentioned above, there is a specific list of motors that are legal to use. With your linear slide...a linear slide goes back and forth along a straight line (it doesn't go side-to-side, or rotate), so it too is legal to purchase.

Now, here's that key: if you purchased that linear slide with a gripper already attached to the slide, or if the linear slide was on rollers (wheels turning about their axles move the slide back-and-forth)...those are more than one degree of freedom, so they would be illegal to purchase. BUT, if you buy a simple linear slide, you buy a legal motor and rollers, and then build your own motorized slide--now that is legal.

As mentioned above, they want you to build your devices, not buy a pre-engineered kit or pre-assembled unit that you just wire up to your robot and go without any effort.