Often times CNC programming tutorials only teach you how to create the tool-paths and not enough attention is paid on showing how to properly hold parts being machined.
At the same time efficient workholding is an art in it self and mastering it could drastically improve shop productivity and accuracy.
Without further ado let's jump into the workflow.
Step 1. Analyze the Drawing and the Model
We would have to look at the drawing, tolerances and the CAD model to develop the machining strategy.
This particular part has tight (+/- 0.001) tolerances between the features located on the top and the bottom sides. In addition to that it has a 2.5 degree draft angle on external walls.
Thus I decided to not use the soft jaws approach and machine it in a fixture. Soft jaws are generally OK for tolerances down to +/-0.001" but because of the draft angle the part would always want to pop out of the jaws.Read More