1. Part clamping in CNC machining

The basic principle of positioning installation is to reasonably select the positioning reference and clamping scheme. The specific principles to be followed are:

(1) The three aspects of design, process and programming should strive to achieve a unified reference;

(2) The number of clamping should be minimized, and the entire processing surface should be processed as much as possible after one clamping and positioning.

2. Basic principles for selecting fixtures in CNC machining

(1) The coordinate direction of the fixture and the machine tool should be relatively fixed, and the dimensions of the part and the machine tool coordinate system should be coordinated as much as possible.

(2) If the processing volume is not large, combined fixtures, adjustable fixtures or other universal fixtures should be used as much as possible to shorten production time and reduce production costs.

(3) If it is mass production, then special fixtures can be considered, but the fixture structure should be as simple as possible.

(4) The loading and unloading of parts should be fast, convenient and reliable, and the parts on the fixture should not hinder the processing of various surfaces of the parts.

3. Machining Errors in CNC Machining

Machining errors in CNC machining primarily include programming errors, machine tool errors, positioning errors, and tool setting errors.

Programming errors are errors introduced during the programming process and consist of approximation errors and rounding errors.

Machine tool errors primarily include CNC system errors and feed system errors.

Positioning errors are errors introduced during the positioning of the workpiece or fixture.

Tool setting errors are errors introduced during the relative positioning of the tool and workpiece.