Why Variable Speed on RO Sanders

[Andy Haney]

I've determined to replace my dime store RO sander. Checking a somewhat recently published tool review, it appears most have variable speeds. RPMs are as low as 5k and as high as 14k. What is the benefit of variable speed, and how should it be used?

Any help is appreciated.

Andy Haney

[David Larsen]

Kinda like the variable speed on a belt sander. It can determine aggressiveness of the sander.

[glenn bradley]

Depending on grit and the surface being worked, a small adjustment in speed can smooth out operation. I've sent my fixed speed units down the road.

[Wally Alexander]

I will slow mine down for certain operations, where control is more important. Like sanding narrow edges, or sanding close to a mating object that I want to be able to keep the sander from venturing into.

[Chip Lindley]

It's FULL SPEED AHEAD for me. I've never owned a VS ROS so I don't miss it. Slow speeds might come in handy to keep from melting plexiglas if you sand that sort of stuff. For hardwood, IMO, faster means quicker sanding, with less scratching. A deft touch is needed to sand edges with an ROS at full speed. But, I control it; it doesn't control me!

[Bruce Wrenn]

I own both single speed and variable speed ROS. But I usually use the one that has the correct grit of paper on it. The VS ones are always set to the max.

[Mike Henderson]

I use the slower speed on my ROS when sanding veneer, especially edges. My problem is that I then forget to crank the speed back up when I next use the sander on jobs other than veneer (duh).

Mike

[Gary Curtis]

Two things you want to minimize while sanding —

a) heat buildup
b) accumulation of sawdust

A lower speed improves on both levels. Aside from the risk of burning the wood with too much speed, grinding and regrinding the same sawdust kills your sandpaper. You want to get that sawdust out of the way.

Few sanders have built-in dust collection (I think Festool does). But with slower speed, the exhaust blast from the motor will have a chance to blow away at least some of the dust.

A few years ago FWW magazine did a test on abrasives durability, with pictures.

[Mike Schuch]

I never run my Porter Cable right angle random orbit sander on anything except full.