I've used a 1" belt sander (I had a 1X42, then when that gave up the ghost I got a 1X30 at HD for $40, give or take) since I learned how at Shofner's World of Knives (Waikiki in the early 80's).
Needless to say, you've got to be real careful not to burn the temper on the blade, nor do you want to eat up your blade too quickly. I use a 180 grit belt for really dull knives, a 320 for blades I've already sharpened on the sander before and are not too dull, and rarely a 100 grit for rough shaping/regrinding.
After the edge is ground, I back-steel the edge on a fine diamond hone, then give it a half-dozen strokes on each side (yeah, yeah Mac, that's what she said). Done properly, a machete will ribbon up a sheet of typing paper.
For my pocket knife, I use a Lansky. Once the edge is dulled, I use the diamond hone to touch up the edge until I get the urge to redo the whole thing on the Lansky again.
So, in sticking to the topic, I use and like the Lansky sharpener and a kitchen knife type fine diamond steel.