SCIENCE AND TECHNOLOGY ENGLIAH FOR MECHANICAL ENGINEERING 2. A set-up is part of an operation performed without reclamping the workpiece. More set-ups reclamping of the workpiece in an operation cause more‖二次装夹 time and more set-up errors. For this reason, when a workpiece must be machined at different positions on a machine tool, a workholder often is employed. This can change the position of the workpiece without unclamping it. In this case there will be several different positions after a single set-up In the previous example, if an index base or index分度头 swivel-type fixture is used, which can change the‖ swivel旋转 position of the workpiece without unclamping‖ fixture夹具 then the milling of the shoulders is accomplished In two positionsSCIENCE AND TECHNOLOGY ENGLISH FOR MECHANICAL ENGINEERING 2. A set-up is part of an operation performed without reclamping the workpiece. More set-ups of the workpiece in an operation cause more time and more set-up errors. For this reason, when a workpiece must be machined at different positions on a machine tool, a workholder often is employed. This can change the position of the workpiece without unclamping it. In this case, there will be several different positions after a single set-up. reclamping 二次装夹 In the previous example, if an index base or swivel-type fixture is used, which can change the position of the workpiece without unclamping, then the milling of the shoulders is accomplished in two positions. index 分度头 swivel 旋转 fixture 夹具