Principles Of Machining
The focus of purely basic level considerations is how to reduce errors and improve accuracy, so the basic principles for selecting essential surfaces are:
First: the principle of benchmark coincidence. The design datum as possible should be selected as the positioning datum. Especially in the final completion, to ensure accuracy, you should pay more attention to this principle. This can avoid causing position error reference deviation;
Second: the principle of benchmark unification. Various surface treatments of a unified positioning datum surface should be selected to try to ensure the position accuracy between surfaces; sometimes the principle of a common datum is followed and repeated processing is performed;
Third: the principle of self-centeredness. Some small machining allowances and a unified finishing process ensure machining quality and productivity, with the precision machining surface itself as a basic level.
