Posted by Mark Bronkalla on August 18, 19103 at 12:22:57:
In Reply to: Re: Riviera to ambitious for beginner? posted by F NC on August 18, 19103 at 04:58:36:
Sorry, got lazy with my typing.
RO = Random orbit - woodworking term - typically electrically driven
DA = Dual Action - autobody term. - typically air driven
Both use the same motion of an orbiting center of rotation for the spinning sanding disk.
The reason gfor a right angle units that these are much heavier duty devices than the vertical / palm / pad sanders. You want to be able to sand enough each day so that your arms are tired, rather than the motor over-heating.
The air powered units also work, but you need a BIG compressor (and prefreably air dryer) to keep up. I only put up with the compressor noise when sanding with the air file. It is a reasonable trade-off. Even so, you could feel the heat radiating off the compresor and tank from several feet away after sanding for an hour or so (6.5 hp vertical air compressor ran continuously).