One-Speed Versus Variable-Speed Random Orbit Sander
A discussion of random-orbit sander characteristics. October 25, 2006
I am about to purchase a random orbit sander. Is there any practical application benefiting from variable speed?
From contributor L:
This is only my opinion because I have never used a variable speed OS. I don't think I would see any benefit in slowing down your sander, because it would make more swirl marks. If you were talking about a belt sander, then yes; a ROS, I wouldn't and I haven't.
From contributor J:
I have noticed a big difference in being able to regulate the speed when you want to take something down quickly. I've noticed that using a slower speed with the right pressure down will take off a lot more material quicker on some species than going full speed. It will also keep the paper from loading up, or getting dull so quick. That is with a Bosch electric - not a cooper or Dynabrade air.
From contributor M:
Spinning too fast can generate too much heat and your paper will load up. Also, different materials do better with different speeds.
From contributor U:
These guys are right on; it all depends on what you do. However, something else to consider, variable speed sanders tend to break down sooner than single speed sanders. I have used multiple brands and it's the same story. After time, dust gets inside and affects the variable speed mechanism and the sander will not stay at the speed you put it at. Same story with variable speed routers. If you work as a hobby in the garage, I wouldn't worry about it too much. I make cabinets and furniture for a living, use them everyday and never have had a need to use a slower speed. I'd buy a single speed and learn good techniques or buy a pneumatic if you have an industrial duty compressor.
From contributor F:
Different grits and different wood hardness or other surface makes the variable worth its weight every time. I have and use both, but more because of design or weight of the tool. Air is most efficient, but the Bosch 3727 6" electric is so versatile that it's never far from reach. The 3727 has the only hook and loop pad in the shop, which adds to the versatility.
From contributor A:
You should be more concerned with the orbit. The better sanders, Festool is one, let you choose between a 3/32 and a 3/16 orbit, although the actual orbit size will vary from one manufacturer to the next, but they are about the same. Never skimp on your sander - you will kick yourself in the rear for it.
From contributor F:
Some sanders, Beaver Air Tool for example, offer a choice of orbit. Smaller is preferred for solid surface, while larger cuts faster in wood. The speed of a better air sander can be controlled with air flow/volume.