RO is
Random
Orbit, which is different from rotary.
A rotary forces the pad to rotate around a central spindle.
On a random orbit machine the pad is not forced to rotate. It moves in small orbital arcs.
A dual-action random orbit machine (DA) allows the pad to spin freely around a spindle that is mounted offset form a motor driven spindle. This
allows the pad to rotate as it orbits but it is not
forced to rotate.
Some RO machines from Makita, Festool, Bosch, etc have two operating modes. They can be used as dual-action random orbit machines or locked into a forced orbit motion. The forced orbit
is not the same a rotary but it’s aggressiveness is somewhere in between a rotary and a DA.
Although all rotaries I have seen operate
only as rotaries, Dynabrade has a kit that converts a rotary to large DA by attaching a DA mechanism.
PC.