Operation skills for using the center frame of machine tool accessories:

1. Application form of center frame

1) Support the center frame on a suitable support surface in the middle of the workpiece, and support the center frame on the auxiliary sleeve.

2) One end is clamped, and the other end is supported by a center frame. This usage form is mostly used for turning end faces and center holes, as well as turning deep holes on long axes, such as turning or repairing conical holes in lathe tailstock sleeves.

2. Operation essentials of the central frame

1) The operation procedure of the center frame is to fix the center frame behind the bed. In the rotating state of the workpiece, first make the lower two support claws evenly touch the workpiece support surface and lock it, then tighten the upper cover and adjust the position of the upper support claws Lock it properly. The support claws of machine tool accessories should have uniform force, moderate elasticity, and natural smoothness.

2) Each supporting claw should apply balanced force to keep the supporting surface in its original spatial state, that is, the supporting surface should be coaxial with the rotation center of the main shaft, in order to prevent uneven pressure on each supporting claw from deviating from the center and causing over positioning.

Overpositioning can cause the workpiece to have a taper, and in severe cases, the workpiece may frequently twist during rotation, resulting in the workpiece coming out and causing accidents.

3) When using the clamping form of clamping one end and supporting the other end with a center frame for machine tool accessories, the workpiece should be aligned using a symmetrical cross centerline or by detecting the upper and side busbars. The machine tool accessories are determined by the three supporting claws of the center frame itself. The function of D is to adjust each claw to determine the spatial position of the support surface. At this time, use a dial or dial gauge to measure, and the swing value will always be zero. Is the clamping position of the workpiece correct at this time for machine tool accessories? Machine tool accessories are in use in this state. When the drill is close to the end face of the workpiece, the center drill will inevitably deviate from the center of rotation of the workpiece. Only when the center drill is aligned with the center of rotation of the workpiece, can the operation of drilling the center hole be carried out. That is, the symmetrical cross centerline or the upper and side busbars of the workpiece must be used to make them parallel to the lathe guide rail, so as to align the workpiece and make the axis of the workpiece coincide with the center of rotation of the spindle.

4) When supporting the surface of workpieces with high precision, in order to prevent the wear of the supporting claws on the workpiece surface, a layer of pure copper sheet or fine sandpaper should be placed between each supporting claw and the supporting surface of the center frame, and the back of the sandpaper should be attached to the workpiece surface. When there are keyways or notches on the surface of the workpiece, brass collars can be used to install it on the outer surface of the workpiece as the support surface for the center frame.

5) Regularly add lubricating oil to the support claws to alleviate wear and tear.

6) Check the wear condition of the support claws at any time, and adjust them promptly when the support is loose.