Lansky Pedestal Mount

This mount allows you extra control by leaving one hand free to just steady the knife instead of holding the knife and clamp or using a vice.
I fixed mine to a polypropylene chopping board and the extra stability really helps ease the strain on your arm and hand during long sharpening sessions.
If you buy two and a couple of extra clamps it allows you to keep steady and the sharpening angle constant when sharpening long blades. I've sharpened a 20" cutlass with no problems and it would be no problem for machete etc.