The following three points should be noted when determining the positioning reference and clamping scheme:
(1) Strive to unify design, process, and programming calculations.
(2) Minimize the number of fixtures, and make it possible to machine all surfaces to be machined after one positioning.
3) Avoid employing manual adjustment programs.
The fixture should be open, and its positioning and clamping mechanism can not affect the cutting tool in the process (such as collision). When encountering such a situation, the fixture can be clamped with a vise or a baseplate