The following four points should be noted when determining the positioning basis and clamping scheme:

(1) Strive to unify the standards of design, process and programming calculation.

(2) Minimize the number of clamping times, and as far as possible, all the surfaces to be processed can be processed

after one positioning.

(3) Avoid using manual adjustment schemes.

(4) The fixture should be open, its positioning, clamping mechanism can not affect the machining of the knife

(such as collision), in such cases, you can use a vise or add the bottom plate to pull the screw.