Review on 🐏 Big Horn 4 Inch Self Centering (Model 19138) by Chris Owens

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 spring to slide past the clip. Once the end of the spring passes this clip, the bit will not retract and you will lose your $14.99. Other designs have a washer between the spring and the C-clamp to hold the spring in place. Thing looks like a not-so-cheap copy of the Insy-Bit, made by someone who has no idea how this attachment is supposed to work. Spend your extra dollar and buy an Insty bit. The attached video clip shows both this beat and a really working insty bit I got from Rockler a few years ago.