1. The inner cavity and shape of precision CNC machined parts should preferably adopt a unified geometric type and size. In this way, the tool specification and the number of tool changes can be reduced, the programming is convenient, and the production efficiency is improved.
2. The size of the inner groove fillet determines the size of the tool diameter, so the radius of the inner groove fillet should not be too small. The manufacturability of the parts is related to the height of the processed contour and the radius of the transfer arc.
3. When milling the bottom plane of precision CNC machining parts, the fillet radius r of the groove bottom should not be too large.
4. A unified datum positioning should be adopted. In precision CNC machining, if there is no unified datum positioning, the position and size of the contours on the two surfaces after machining will be uncoordinated due to the re-installation of the workpiece. To avoid problems and ensure the accuracy of their relative positions after two clamping operations, a unified datum positioning should be used.
Matters needing attention: It is best to have a suitable hole on the part as a positioning reference hole. If not, set a process hole as a positioning reference hole (such as adding a process lug to the blank or setting a process hole on the allowance to be milled in the subsequent process). ). If the process hole cannot be made, at least the finished surface should be used as a unified reference to reduce the error caused by the two clamping. In addition, it should also analyze whether the required machining accuracy and dimensional tolerances of the parts can be guaranteed, whether there are redundant dimensions that cause contradictions or closed dimensions that affect the process arrangement.