Power Sharpener for MMM Blades

What is the best tool to put a factory sharp edge on mower blades? I use a disk grinder with the blades in a vise. It works but not perfect.

ANY BETTER IDEAS OR TOOLS,

Thanks

I typically use a bench grinder for mine. I have used a angle grinder before and clamped the blade in a horizontal position just like when it is mounted and that works too. Some have talked about sharpening them still on the deck but I have never done that and don't have the tool for that.

Gary

I've used a bench grinder, an angle grinder, and a belt sander with about a 100 grit belt. Depends on what's handy. I've also used a belt grinder. You know, the upright kind that uses a 2" belt. They all work well. The important thing is to not over heat the steel. I find over heating happens easily with the bench grinder. Less so with the belt sander. Maybe because it's working over a larger area?