HF 12" Direct Drive Disc Sander

[gaj1967]

final_t asked if using a TS with a sanding disc was worthwhile: http://www.bt3central.com/showthread.php?t=29902

I'd rather not take the risk of wearing me BT3k out before it's time so my question is whether or not the HF 12" Direct Drive Bench Top Disc Sander is any good:
http://www.harborfreight.com/cpi/cta...emnumber=43468

Right not it's listed in the mail-out for $99.99 (reg $129.99) and I have a 15% coupon which would bring it to $84.99. Since I missed the OSS sale would this snder be a good buy?

And does anybody know if you can put a speed control on it? What about paper for it? I only see 60 grit at 12" but see smaller diameters.

Hmmm, at +80 pounds I might just forget about this one and look at a belt/disc combo sander instead. lol

[Hoover]

If it is an induction motor, no you cannot use a speed controller. It is most
probably an induction motor, so no controller

[messmaker]

I may be in error but I don't believe the the big disk sanders I have seen were multi-speed.

[LCHIEN]

Here's my take for WIW - I've not used a disk this big BUT

In the discussion on 10" disk sander adapters for TS I suggested that the linear speed was too fast on this disk using the BT3x which turns near 5000 RPM. I suggested a 6" disk sander runs a linear speed around 1/3 or 1/4 of that and said a speed controller was possible on the BT3x with its universal motor. Sanding at too fast a linear speed I predict will overheat the sandpaper and the work leading to burning of the wood and glazing over of the sandpaper.

With the HF 12" disk, the RPMs are much less, 1750 according to the spec. That would give a linear speed at the outside similar to my 6" disk sander.

Furthermore, a speed control is NOT truly necessary on a disk sander, especially one this big. That's because you work on the side of the disk, not the edge, so this doesn't hold for a table saw.

The sanding velocity is proportional to the radius...thus to sand at full speed you hold it near the perimeter (on the down-going side, PLEASE).
To sand half the speed (and half the rate of material removal) sand about 3" from the center to the edge (halfway). At the center, the radial speed is the same but the linear speed is nearly zero. Voila, Speed control!

With a big 12" disk, its easy to control the speed and you have lots of sanding material - that's why a big one is nice.