This thing self-destructed on the first hole. Firstly, the drill is barely held by the set screw and will pop right out. Sawing a flat section on the drill will help the set screw hold it securely. It's annoying but fixable. A fatal design flaw is that there is nothing holding the spring in place, causing the entire structure to fall apart almost immediately. There is a clip that is supposed to hold the spring, but when the spring is compressed its diameter increases just enough for the springβ¦