1. The operation procedure of the central frame is to fix the central frame behind the bed and make the lower two supporting claws touch the supporting surface of the workpiece evenly before locking, then fasten the upper cover, and adjust the position of the upper supporting claw. When the workpiece is rotated, the upper supporting claw is locked properly. The supporting claws of machine tool accessories should be uniformly applied, moderately tightened and naturally smooth.
2. Each supporting claw should apply force equally so as to keep the supporting surface in its original spatial state, i.e. the supporting surface and the rotating center of the spindle are coaxial, so as to prevent the pressure of each supporting claw from being uneven and deviating from the center, resulting in over-positioning. Over-positioning will make the workpiece taper. In serious cases, the workpiece will twist frequently when it rotates, which will lead to the occurrence of accidents when the workpiece comes out.
3. When clamping one end of a machine tool fittings and supporting the other end with a central frame, symmetrical cross-centerline or detecting the upper and side buses should be used to locate the workpiece. Machine tool parts because the three supporting claws of the center frame are fixed by itself. The spatial position of the supporting surface can be determined by adjusting the claws under D action. At this time, the swing value of the supporting surface is always zero when measured by a scribed disc or a percentile meter. Then, is the clamping position of the workpiece correct? Machine tool parts in this state, in use. B drill is close to the end face of the workpiece, then the center drill must deviate from the revolving center of the workpiece. only when the center drill is aligned with the revolving center of the workpiece, can the center drill be operated. That is, the symmetrical cross center line or the upper and side buses of the workpiece must be used to make them parallel to the lathe guide so as to find the workpiece and make the workpiece axis correct. It coincides with the rotation center of the spindle.
4. In order to prevent the supporting claw from wearing the workpiece surface when supporting the most precise workpiece surface, a layer of pure copper sheet or fine sand cloth should be padded between the supporting claw and the supporting surface of the center frame, and the back of the sand cloth should be attached to the workpiece surface. When there are keyways or notches on the surface of the workpiece, brass sleeve rings can be used as the support surface of the center bracket on the outer surface of the workpiece.
Fifth, lubricating oil is often added to the supporting claw to lighten the wear of the supporting claw.
6. Check the wear condition of the supporting claw at any time, and adjust it in time when the supporting claw is loose.