I use this disc sander and a jig.. They have served me very well for many years on many pads. i recently did a Decelerator, for a friend, using it. It is a beast, as far as weight, power and smoothness of operation. I have to move it to my workbench, where there is ample lighting, each time I use it, and connect it to a ShopVac to catch most of the rubber grindings. At about 60 lbs. I don't move it any more than i have to. Never used it for anything other than grinding recoil pads. Very smooth running.
As far as the difference between it and a belt sander I can't see where it would much matter. I use the "down side" of the disc (left side) to do the pad grinding, much as a belt sander would be, as the belt would be going down to do the grinding/sanding. I always finish up by hand sanding.
https://www.harborfreight.com/12-in-1-14-hp-disc-sander-58862.html
