MET 426 CNC Machining Resit 2022

About this paper

MET 426: A 2-page Resit Examination for CNC Machining (MET426), University of Buea, Level 400, instructor Tsamo Nestor, dated June 2022, 2 hours. A companion/expanded sitting of the same course as the August 2021 resit. Part One: four short questions on writing a Numerical Control program, the meaning of a Digital Order ADDRESS, application areas of G-code programming, and optimizing CAD/CAM programming costs. Part Two Exercise 1: a contextual multi-view diagram (front and top views) of a workpiece with six labelled tool-path points, requiring the student to fill a coordinates table and write an ISO G-code program for a milling cutter at S=2500 rpm, F=300 mm/min -- reusing the same geometry as the companion paper. Part Two Exercise 2: a more complex pocket-machining exercise on a 'Candle support' part (an 80x80 mm plate with rounded corners and a 4-lobed cross-shaped pocket), requiring the student to execute five sequenced machining steps (rough outer, centre drill, rough pocket, precision outer, precision pocket) using a table of five end-mill tools with their spindle speeds and feed rates.