One approach to machining a hole is to feed a milling tool a

One approach to machining a hole is to feed a milling tool along a helical path (please see Figure), as opposed to using a drill. Compare the advantages and limitations of this approach in relation to drilling.

Solution

1. Advantages

a. the surface finish will be better by milling.

b. the dimensional accuracy will be more by milling.

c. one single milling cutter can be used for various hole sizes of different diameter,whereas in drilling one different sizes of hole different drill bits are required.

Limitations

a. length/depth of the hole will be limited due to small thickness of the cutter, whereas the drill bits are larger in the length.

b. time required to cut the hole will be morte as compared to drilling.

c. a skilled labour is required to generate codes for helical milling in the CNC.