I do almost everything on the grinder. Starting out with a worn out 400 grit for carbon steel blades. I use two different types of edges..... a "working" edge is the worn 400 grit belt, and that's it. When sharpening a "collector" piece, it's the worn out 400 grit belt, then a pass on each side of the blade's edge with a loose buff and pink No-Scratch. This gives a "scary" sharp edge, that will shave hair all day long, but it's not the best edge for a "working" knife, hence the reason I only use the belt on a working edge, and forgo the buff.
As Anthony said..... its on a variable speed machine, with the speed WAY down....usually in the 20% range on the controller, and I use a slack belt area to achieve a convex edge. I think it bears mentioning that in order for it to work well, the closer to a "zero" edge grind you can get when finish grinding, the better.