?? My New Milwaukee 6021-21 Random Orbit Sander

[Randall Clark]

I just bought a new Milwaukee ROS, and it doesn't spin nearly as fast as my old Ryobi rs115. Is this normal or could there be something wrong?

[Randall Clark]

Do the new random orbit sanders spin slower than the older ones?

[Michael Stanley]

I don't recall that my 6021 orbits any slower then a PC ros that I have. I'm not familiar with the Ryobi. Does the Milwaukee seam to be sanding efficiently?

Not to state the obivious but you do have the speed control at max?

[glenn bradley]

I would check your manuals for the specs to determine if this is expected behavior. I notice the Milwaukee (7000 to 12000) speed is the same as my Bosch 1295DVS. Do you have the variable speed set to high?

[johnny means]

Are "random orbit" sanders supposed to "spin". I think an RAS spinning fast is a bad thing. I notice that mines usually start to spin at ridiculous speeds when they start to wear out. Maybe your new sander is "randomly orbiting" like it should.

[Cliff Rohrabacher]

They slowed them down because too many people were suing after getting friction burns when they left them on, dropped 'em onto the couch, and then sat on them while watching the latest edition of Idol.

Now the new OSHA regs require that you be able to sit on one for a half hour while wearing a thin cotton shift.

[Chris Tsutsui]

Cliff, I was wondering why young women ask to buy the most poweful ROS's, but I guess you hit the nail on the head.

Anyways, when you depress a ROS on a surface, it's not supposed to be spinning fast, but make small tiny orbital circles.

If it spins then that would be a rotary sander that can cause swirl marks...

So in other words, I don't think the RPM the disc spins under no load is an indication that it's functioning properly.

If the device is spinning fast while in use with pressure then there may be a fault.

[Randall Clark]

I'll check the manual. I'm just not convinced that it's going fast enough. At times it hardly spins at all.

[glenn bradley]

I'll check the manual. I'm just not convinced that it's going fast enough. At times it hardly spins at all.

Correct. The 7000 to 12000 number pertains to the orbits per minute, not revolutions. A ROS does not spin like a grinder. It will spin but, if it spun too fast it would leave swirl marks that are the very thing they are designed to avoid.

When tested for reviews, the most telling indicator of how smooth a finish the sander will leave is to run it on a piece of plastic and study the pattern left behind. The pattern is something like a 3/16" to 3/8" orbit combined with a slow spin to create a random pattern. The larger the offset, the more aggressive the sanding. The spin creates the randomness of the orbit pattern by constantly altering the angle of attack, so to speak. If the rotation (or the orbit) were to be dominant, the pattern would become predictable and noticeable.

[kenneth kayser]

I'll check the manual. I'm just not convinced that it's going fast enough. At times it hardly spins at all.

If you can, go to a store and compare yours with another one of the same model.

[John Thompson]

I'll check the manual. I'm just not convinced that it's going fast enough. At times it hardly spins at all.

Ditto Glenn on spinning fast. I can't compare your Milwaukee to a Ryobi but.. I can to a PC 333. The PC spins very fast making it extremely agressive. You can't sit it down for about 20 seconds after you turn the PC off or it will walk on the surface you sit it on. The Milwaukee I purchased simply does not. But... as mentioned the MW won't leave as many swirl marks.

I would not be concerned about how fast it spins but instead the finish is leaves. I like the new MW so well.. I sold my Bosch and bought a second one which give's me two MW's to avoid grit changes which speeds up my finishing. I also have a Ridgid 6". I kept the PC for aggression on rough jobs as finalizing a work-bench top after hand planing flat.

BTW.. the dust hook-up on the MW is very solid compared to my old PC and the chin-cey deal (IMO) on the Bosch I had. It makes either a 2 1/2" or 1 1/2" hook-up a snap as I have both hoses on different shop vacs.

Hope that helps...