Dual Action -v- Orbital -v- Random Orbital: Any Differences:

[Tom and Vipers]

Need to buy a body sander and was wondering what the differences are.

I know of 2 types of pad motion:

1) I'll call one "translational" where the pad translates in a circular motion about a fixed point. The resulting diameter is maybe 1/4 inch. This action is usually found on square pad sanders.

2) I'll call the other "rotational" where a round pad rotational axis moves in the "translational" method. The round pad freewheels on this axis. This action is usually found on round pad sanders.

Does anyone know the precise definition of these motions?

Thanks in advance,
Tom