CNC Milling

Zach Burt
Andrew Bortz
Dhananjay Lodha

CNC Milling, or Computer Numerically Controlled milling (CNC) is the process of machining physical objects from 2D or 3D digital information, which is imported from CAD or other design programs converted to a specific language understood by the machine.

The process of CNC Milling is a 2-Step Procedure.

Step 1: Toolpathing

• Toolpathing is the process of translating a 2D or 3D computer model into a series of "paths" for the CNC mill bit to follow as it excavates the model from a block raw material

Step 2: Machining

• Machining involves translating the toolpaths into commands to small stepper motors in the milling machine that move the head incrementally in the X, Y and Z directions.
• Bit Size
• Bit Tip
• Flutes
  

Advantages of CNC Milling

• Very good for one-off or geometrically simple objects
• Virtually any material can be milled with a proper cutter, therefore costs are low
• Complex parts can be milled with high detail
• Tolerances of 0.001" to 0.003" are possible
• Weights of parts from a few grams to up to 100 lbs
  

Disadvantages of CNC Milling

• A more reduced set of features possible
• Certain features are not possible, including internal shapes or parts
• Size limitations depend on the actual CNC machine used
• More material waste than casting type processes
• Quite slow
  

03/11/2003