Kind of a dumb question. What's a disc sander good for?

[dbhost]

Well, my OSS / OBS (oscillating spindle sander / oscillating belt sander) is the Ridgid, which is a very nice piece of gear, but I just got curious why folks seemed so fond of the discs...

[pelligrini]

Aren't the oscillating types fairly new tech? I've never really seen an old rockwell oscillating sander for sale. I also wonder about the longetivity of the oscillating types.

[dbhost]

Maybe for the small benchtop units. I recall in High School wood shop we had a Rockwell oscillating spindle sander. I have seen much larger Oscillating edge belt sanders as well from that era. I'm not saying how long ago that was, but it was a LONG time ago...

And I have seen Ridgid EB4424 sanders with date stamps going back to the late 90s so the bench top jobs have been around at least 10 years...

A local shop near me uses the Ridgid HEAVILY on a daily basis making cedar lawn furniture like swings, Adirondack chairs, picnic tables and the like, and I do not believe they have managed to break one yet, but can see HOW you could break one. It would take a fair bit of abuse, but it is certainly not steel and cast iron...

I am pretty confident the tech is there, and pretty solid. I had considered one of the combination disc / belt machines prior to getting my Ridgid unit, but I REALLY wanted the oscillating feature, not to mention the spindle feature. The oscillating sanders in my experience tend to burn less, and leave a smoother finish (no straight line scratches or swirls) at a rougher grit. I guess it is also partially due to the fact that oscillating sanders are what I learned on so many years ago...

[Mr__Bill]

Another interesting attribute of the disk sander is the built in variable speed. Not RPM but FPM, the outside moves much faster than the center. You can rough in the curve on the out side of the disk and do the fine work towards the center where it cuts much slower, all without taking your hands off of the work or changing paper.

Disk sandere are also very quiet and a good one spins without vibration. The only downside I see is the sanding disk is glued on and changing them can be a pain, scraping off the old disk and glue and prepping the surface.

Bill,

[LCHIEN]

Another interesting attribute of the disk sander is the built in variable speed. Not RPM but FPM, the outside moves much faster than the center. You can rough in the curve on the out side of the disk and do the fine work towards the center where it cuts much slower, all without taking your hands off of the work or changing paper.

Disk sandere are also very quiet and a good one spins without vibration. The only downside I see is the sanding disk is glued on and changing them can be a pain, scraping off the old disk and glue and prepping the surface.

Bill,

all good points.
I had my Ryobi BD3600 fling off a heavier weight (thicker than normal) PSA disk and man, that hurts. Make sure the surface is clean and the disk well stuck on.

[sscherin]

You can get 10" flat metal disks with a 5/8" arbor hole to turn your table saw into a 10" disk sander. 10" sanding disks with PSA are available for this. The blade tilt makes it a precision miter table. The BT3 having a universal motor makes it easy and safe to use a router speed control if 4-5000 RPM is too fast (might be). Having a table and all and bigger it would be quicker and easier than making a lathe into a disc sander.

here, woodcraft has them for under $20:
http://www.woodcraft.com/Product/200...-Disc--10.aspx
they also have 10" PSA-attached sandpaper disks in 40 to 120 grit linked on the bottom of that page.

Thanks for the tip
My old Gil-Bilt saw just found a job to justify it's existence.
I wonder if they make a 12" backing plate..

[tjr]

I recall seeing an idea for a more-or-less free DIY 12" disk sander made outta a fan motor from a junked furnace (probably a 1700 RPM motor) on a wood stand with a wood work table. Disk was made by cutting a particle board circle, roughly lining it up to center and screwing it to the pulley with 4 screws, then truing by running the motor and sanding the edge and face of the disk to a perfect flat circle.

[RodKirby]

all good points.
I had my Ryobi BD3600 fling off a heavier weight (thicker than normal) PSA disk and man, that hurts. Make sure the surface is clean and the disk well stuck on.

I use "loop" backed sanding disks. I was able to get super-stick "hook" backing for the aluminum disk. The (very) slight "give" in the hook/loop setup does not effect sanding accuracy and swapping disks is a breeze