Guidelines for CNC precision parts machining

In The Design Of Process Standards, The Correct Selection Of Positioning Data Has A Vital Impact On Ensuring Part Processing Requirements Reasonably Arranging The Processing Sequence.CNC Precision Parts Processing

Positioning References Are Divided Into Fine Datum Rough Datum: The Rough Datum Uses The Unprocessed Surface Of The Blank As The Positioning Datum, While The Fine Datum Uses The Processed Surface As The Positioning Datum.

01Criteria For Selecting Precision Benchmarks

(1) Datum Coincidence Principle: The Surface Design Data After Processing Should Be Selected As Accurate As Possible To Prevent Positioning Errors Caused By Data Misalignment.

(2) Consistent Datum Principle: In Order To Ensure The Relative Position Accuracy Between The Machined Surfaces, As Many Surfaces As Possible On The Workpiece Should Be Machined Using The Same Set Of Precision Datums.

(3) Reference Criteria For Workpiece Machining Surfaces: The Repeated Machining Method Of Two Machining Surfaces Can Be Used As Mutual Reference.

(4) Self-Reference Criterion: Some Surface Finishing Processes Require Small Uniform Machining Tolerances, The Processed Surface Itself Is Often Used As The Accuracy Reference.

The Four Criteria For Selecting Precision Benchmarks Mentioned Above Are Sometimes Impossible To Meet At The Same Time Must Be Decided Based On Actual Conditions.

02Criteria For Selecting Rough Benchmarks

(1) The Rough Datum Should Be Used During The First Workpiece Processing. Whether The Rough Datum Is Selected Correctly Only Affects The Processing Of The First Process, But Also Has A Great Impact On The Entire Process Of The Workpiece.

(2) Principle Of Reasonable Distribution Of Machining Tolerance: The Machining Allowance On The Workpiece Surface Should Be Kept Uniform, The Important Surface Should Be Used As The Rough Reference.Non-Standard Precision Parts

(3) Easy Clamping Principle: In Order To Ensure Stable Positioning Reliable Clamping Of The Workpiece, The Selected Approximate Reference Point Should Be As Smooth Clean As Possible, Without Lightning Strikes, The Forging Cuts Other Defects Should Allow For Sufficient Support Area.