Was a machinist back in the 70's. But since then have been more of a home hobbyist. I used to sharpen my drills by hand with the aid of a drill angle guide. Then I found the Drill Doctor and thought that would make a dreaded task much better. That thing is plastic junk. A LOT of guesswork. Then I saw the YouTube review of this machine by Tubalcain. Decided to bite the financial bullet & get one. Well, (other than the cost) this thing has been an answer to my dream of an easy to use & PRECISE drill sharpener. Heavy duty, made entirely of steel. (Made like the US USED TO make things). Dead on exact drill bit sharpening every time. It is made & designed in all metric but that's not a problem. Just pick the collet that fits the drill, align the drill, and sharpen. Hate the price but LOVE the machine. (I gave away my Drill Doctor).