I've been thinking about buying one of these but I don't know if they are just a gimmick. Also, if they genuinely work well how good do your bits need to be in the first place to be worth sharpening?

27 August 2008: Leading workholding systems and machining accessories supplier 1st Machine Tool Accessories (1st MTA) has announced a 20% discount offer on its top-of-the-range Darex XPS-16 CNC drill ...