From Drawing to Part

Machining is the trade that makes the parts of every other machine. This chain shows how a single part moves from an idea to a working object.

Tolerance

A drawing does not say "make it 1 inch". It says 1.000 inch plus or minus 0.001 inch, because nothing can be made perfectly and the drawing must say how imperfect is acceptable. Tolerance is the language shared by the drafter, the machinist and the inspector. Interchangeable parts, one of the foundations of industrial production, depend on it.

From handwheels to code

For most of history a machinist turned handwheels. In 1952 MIT demonstrated a numerically controlled milling machine for the U.S. Air Force, following work by John T. Parsons; computer numerical control (CNC) followed as computers shrank. Today CAD models feed CAM software that writes G-code, the instructions a CNC machine follows. The machinist sets up the job, selects tools, proves the program, and watches the cut, because a crash can destroy a spindle.

Inspection

Parts are checked with calipers, micrometers, height gauges and, for complex work, a coordinate-measuring machine (CMM). Quality records show the part met the drawing.

Programs on this chain

Drafting/CAD, CNC machining, robotics/mechatronics, industrial maintenance, marine engine, and welding for fabricated parts. Credentials: NIMS Machining, Haas, Mastercam, Autodesk.