Prosumer Products, Tools, and Machinery Design Rotation Saw Power Saw by Hoyoung Lee A Power Chain Saw with a Revolving Handle. This chain has a handle that revolves 360° and stops at predefined angles. In general, people cut trees horizontally or vertically by turning their saws at certain angles or leaning or tilting their body parts. Unfortunately, the saw often slips from the user’s grasp or the user has to work in an awkward position, which may cause injuries. To make up for such drawbacks, the proposed saw is fitted with a revolving handle so that the user can adjust the cutting angles.