What's the difference between dual action and random orbital

[rick71ghia]

Probably a stupid question, but what is the difference between a random orbital sander and a dual action sander? I did a search here and could not find an answer.

In searching manufacturer's sites (Hutchins, Dynabrade, National Detroit) I couldn't find much either. The only thing I found close to a definition was on the Dynabrade site for the 10754 Dual Action Sander. It said it could switch between a 3/16" random orbit and a rotary orbit.

In reading various threads here, it seems like the term random orbital and dual action are used interchangeably.

[diy570]

a "true" dual action sander has two functions, random orbital and grinder mode. you have to flip a ring on the shaft to switch from one to the other. a lot of da sanders are referred to as such, but not a true dual action sander. i call my hutchins 4500 a da, but its really just a random orbital. i've got a couple cheaper sanders that are true dual action, but never use the grind mode on them cause it kinda sucks compared to an actual grinder.
most bigger companies, hutchins, dynabrade, mac, snap on, etc. are making more random orbital sanders now as opposed to dual action. probably because nobody really uses the grinder function, not to mention a dual action sander is usually bigger, heavier, uncomfortable and sometimes too aggressive. hope this answers your question.
if you are searching the hutchins, dynabrade, nd sites then you are on the right track to buying a good sander that will last you a long time. i really like hutchins for sanders and dynabrade for grinders. 100 times better than snap on, mac, etc.

[rick71ghia]

Thanks, that's what I assumed. You definition matches what I saw on the Dynabrade site.