Would I really notice a difference with a "better" RO Sander?

[Patrick Curry]

You ought to look at the 5" Rigid sold at Home Depot. The vibration is reasonable, the dust control is good, and it performed well for me given the price.
I recently upgraded to a Bosch 6" (~$200)

[Mel Fulks]

I never see orbit size mentioned in these threads and I've worked places where the management wasn't even aware that were at least three sizes. Seems like that needs to be considered in these brand comparisons.

[Bruce Page]

I never see orbit size mentioned in these threads and I've worked places where the management wasn't even aware that were at least three sizes. Seems like that needs to be considered in these brand comparisons.

The Festool ETS 150/3 has a 3mm stroke. (~6"x 0.118)

[Pete Staehling]

I use three 5" ROS with three different grits. Since I work on very small sized projects I tend to use often each grit for seconds at a time. Given that swapping abrasives is a pain. So I have two Dewalts and one cheapie Harbor Freight withe three grits ready to go at all times. I really don't notice all that much difference. The Dewalts are enough nicer that if buying again I'd buy them, but the HF cheapie is actually OK. So I will use the HF until it dies and probably buy another Dewalt at that time (assuming the Dewalts actually wind up lasting longer).

[peter gagliardi]

I never see orbit size mentioned in these threads and I've worked places where the management wasn't even aware that were at least three sizes. Seems like that needs to be considered in these brand comparisons.

This is something many get hung up on, and don't understand well.
You simply want the largest orbit you can get.
And here is why, if a given tool runs at say 10000 orbits per minute, at say 10,000 rpm's, then the math shows that a machine running at a 3 mm orbit can travel, and thus effectively sand an area only about 60 % the size of the machine running the 5 mm orbit. This assumes both machines have the same number of RPM's and OPM's
Put another way, the bigger orbit allows the same amount of sanding in 40 % less time!!! This is huge for us guys that do it for a living.
Someone here is going to point out "the smaller scratch pattern" as being better. False.
Proper sanding technique and order is what makes sure there is NO scratch pattern to see with the naked eye!
^^^^^^ Those are the facts, at least how I see them anyway.

[John Lankers]

This is something many get hung up on, and don't understand well.
You simply want the largest orbit you can get.
And here is why, if a given tool runs at say 10000 orbits per minute, at say 10,000 rpm's, then the math shows that a machine running at a 3 mm orbit can travel, and thus effectively sand an area only about 60 % the size of the machine running the 5 mm orbit. This assumes both machines have the same number of RPM's and OPM's
Put another way, the bigger orbit allows the same amount of sanding in 40 % less time!!! This is huge for us guys that do it for a living.
Someone here is going to point out "the smaller scratch pattern" as being better. False.
Proper sanding technique and order is what makes sure there is NO scratch pattern to see with the naked eye!
^^^^^^ Those are the facts, at least how I see them anyway.

Right, and that's why you get what you pay for.
My 6" Ceros has 5mm orbit at up to (I believe) 12,000 rpm, low profile, very little vibration and excellent dust extraction when connected to a shop vacuum.

[Mel Fulks]

I won't say no one gets "hung up" up on orbit size ,but I think the bigger problem is ignoring it as I've seen shop owners do. I think Peter's comments are helpful but the reviews of sanders ( some of which seem to be just company ads) are pushing the small orbit for final sanding idea. And there are ads for sanders with orbits as big as 3/8 inch. Some )sanders seem to be for trades other than woodworking but the descriptions don't say which one!

[Peter Aeschliman]

This is something many get hung up on, and don't understand well.
You simply want the largest orbit you can get.
And here is why, if a given tool runs at say 10000 orbits per minute, at say 10,000 rpm's, then the math shows that a machine running at a 3 mm orbit can travel, and thus effectively sand an area only about 60 % the size of the machine running the 5 mm orbit. This assumes both machines have the same number of RPM's and OPM's
Put another way, the bigger orbit allows the same amount of sanding in 40 % less time!!! This is huge for us guys that do it for a living.
Someone here is going to point out "the smaller scratch pattern" as being better. False.
Proper sanding technique and order is what makes sure there is NO scratch pattern to see with the naked eye!
^^^^^^ Those are the facts, at least how I see them anyway.

Very informative. Thanks!

[Dave Cav]

Dynabrade.

[Jerry Miner]

This is something many get hung up on, and don't understand well.
You simply want the largest orbit you can get.
And here is why, if a given tool runs at say 10000 orbits per minute, at say 10,000 rpm's, then the math shows that a machine running at a 3 mm orbit can travel, and thus effectively sand an area only about 60 % the size of the machine running the 5 mm orbit. This assumes both machines have the same number of RPM's and OPM's
Put another way, the bigger orbit allows the same amount of sanding in 40 % less time!!! This is huge for us guys that do it for a living.
Someone here is going to point out "the smaller scratch pattern" as being better. False.
Proper sanding technique and order is what makes sure there is NO scratch pattern to see with the naked eye!
^^^^^^ Those are the facts, at least how I see them anyway.

Facts?? I don't think so.

Your math would work if the sanding areas of a 3mm orbit sander and a 5mm orbit sander were only 3 sq. mm and 5 sq. mm respectively. But the sanding area of a 5" sander with a 3mm orbit is 20.572 sq. inches and that of a 5" sander with a 5mm orbit is 21.205 sq. inches.

Area of a circle is pi(R)(R) --- (R=radius) ( I don't know how to type piRsquared)

Radius of 5" sanding pad= 2.5 in. Add 1.5mm (.059 in.)(increase diameter by 3mm means increase Radius by 1.5mm) = 2.559
Total sanding area = 20.572 sq. in. ----- pi(2.559)(2.559)

Add 2.5mm (.098 in.) (5" disk plus 5mm orbit) = 2.598
Total sanding area = 21.205 sq. in. ----- pi(2.598)(2.598)

So total sanding area increases from 20.572 to 21.205 sq. in., or a 3 % (NOT 60%) increase.

I'm not saying that a larger orbit doesn't lead to faster sanding, but the increase in sanding area was over-stated.

[Mike Chalmers]

I went from a 5" Dewalt to a 6" Bosch ROS65VC-6. I still use the Dewalt occasionally on smaller projects, or when I have to do a lot of one hand sanding, but the Bosch is my go to. No comparison. Not a Festool for sure, however, it doesn't cost you your first born either.

[Van Huskey]

Dynabrade.

Great except for dust control and having to run a large noisy electricity hog compressor. With the adaptation of brushless motors allowing ergonomics similar to pneumatic sanders the writing is on the wall for pneumatics which cost far more to run than brushless electrics. Brushless electrics are already making inroads into industrial and commercial settings and will eventually overtake the pneumatics as the preferred solution. This is exactly why Mirka designed their Ceros/Deros to copy the ergonomics of air sanders and Festool did as well, though not quite at the level of Mirka. Mirka and Festool both make very high quality air sanders (as good or better than Dynabrade) which actually have great dust control but now are pushing the long term lower cost of electric sanders which is only possible to convert users due to the compact power and low maintenance allowed by the use of brushless motors.

[peter gagliardi]

Facts?? I don't think so.

Your math would work if the sanding areas of a 3mm orbit sander and a 5mm orbit sander were only 3 sq. mm and 5 sq. mm respectively. But the sanding area of a 5" sander with a 3mm orbit is 20.572 sq. inches and that of a 5" sander with a 5mm orbit is 21.205 sq. inches.

Area of a circle is pi(R)(R) --- (R=radius) ( I don't know how to type piRsquared)

Radius of 5" sanding pad= 2.5 in. Add 1.5mm (.059 in.)(increase diameter by 3mm means increase Radius by 1.5mm) = 2.559
Total sanding area = 20.572 sq. in. ----- pi(2.559)(2.559)

Add 2.5mm (.098 in.) (5" disk plus 5mm orbit) = 2.598
Total sanding area = 21.205 sq. in. ----- pi(2.598)(2.598)

So total sanding area increases from 20.572 to 21.205 sq. in., or a 3 % (NOT 60%) increase.

I'm not saying that a larger orbit doesn't lead to faster sanding, but the increase in sanding area was over-stated.

Ok, in your example, the math as you state, I trust as true, however, if you take it and break it down to the distance each individual grain of grit travels, in its orbital path over 1 minutes time, you will understand what I am saying. It has absolutely nothing to do with pad size vs. orbit size. Each grain is still travelling a given number of times in a given length of orbit. A 3mm circle is still only 60% of the distance of a 5mm circle.
I stand by my assertion.

[Van Huskey]

Ok, in your example, the math as you state, I trust as true, however, if you take it and break it down to the distance each individual grain of grit travels, in its orbital path over 1 minutes time, you will understand what I am saying. It has absolutely nothing to do with pad size vs. orbit size. Each grain is still travelling a given number of times in a given length of orbit. A 3mm circle is still only 60% of the distance of a 5mm circle.
I stand by my assertion.

Not getting into the math I agree with your point 100% with a caveat or two. I find for raw wood there is no reason to go below 5mm (I have never used one fo the 8mm stroke ROS). The place that I find (non-scientifically) that smaller strokes work better is high grit work on film finishes, I like orbits smaller than 3mm (2.5mm or so) in this application. It probably has more to do with fact you don't need quick cutting and large orbits "seem" to show more with the very high grits. I went through a stage where I had both 3mm and 5mm Festool ROS but quickly divested myself of the 3mm 6" version and hen I moved to Mirka just bought 5mm. I do keep 2.5mm a 5" ROS for building and finishing film finishes.

[Leo Graywacz]

This is something many get hung up on, and don't understand well.
You simply want the largest orbit you can get.
And here is why, if a given tool runs at say 10000 orbits per minute, at say 10,000 rpm's, then the math shows that a machine running at a 3 mm orbit can travel, and thus effectively sand an area only about 60 % the size of the machine running the 5 mm orbit. This assumes both machines have the same number of RPM's and OPM's
Put another way, the bigger orbit allows the same amount of sanding in 40 % less time!!! This is huge for us guys that do it for a living.
Someone here is going to point out "the smaller scratch pattern" as being better. False.
Proper sanding technique and order is what makes sure there is NO scratch pattern to see with the naked eye!
^^^^^^ Those are the facts, at least how I see them anyway.

If you are looking for an aggressive sander then I'll agree. If you are looking for a fine finish sander then your theory is wrong.

I have the Mirka Ceros and it has a 5mm orbit. Since getting it I haven't had any issues with swirlies in my finishes. The good sandpaper and the vacuum hookup is the reason for that. Before that I used a single speed DeWalt sander. Pretty much bought 1 per year as they wore out. They didn't have a chance with 500-700 hours sanding a year.