Lecture 8: Material Removal Processes
A Coggle Diagram about MACHINING CENTRES
(Highly automated machine tool capable of performing multiple machining operations under CNC control in one setup with minimal human attention-Typical operations are lathe, milling and drilling
, Other features:
Automatic workpart positioning
Automatic feed of material for new part
Universal machining center (Haas CNC); highly automated, capable of multiple machining operations under computer control in one setup with minimal human attention
and Mill-Turn Machines
Highly automated machine tools that can perform turning, milling and drilling operations on a work part
• General configuration of a turning machine
• Capable of both rotating the work piece (turning) and rotating the tool (milling and drilling)
(Machining process by which a surface is generated by progressive chip removal.
Work is fed into a rotating tool with multiple cutting edgesAxis of tool rotation is perpendicular to feed directionCreates a planar surface; other geometries possible either by cutter path or shape
, Other Milling Processes include:Slab Milling
Conventional Face Milling
(Creates a round hole in a work part.
Cutting tool called a drill or drill bit.
Normally performed on a drill press.
Accounts for ~25% of all machining processes performed.
, Through Holes vs. Blind Holes
Through‑holes - drill exits the opposite side of work
Blind‑holes – drill does not exit work on opposite side
and Other Drilling Processes include:1-Reaming
(A single point cutting tool removes material from a rotating work-piece to generate a cylindrical or conical shape. Variations of turning that are performed on a lathe:-Facing
and Boring is an internal turning operation
Boring is performed on the inside diameter of an existing hole
Turning is performed on the outside diameter of an existing cylinder
), SHAPING AND PLANING
Both use a single point cutting tool moved linearly relative to the work piece
Creates a flat surface
Low cutting speed
(Power Hacksaw – linear motion of the saw blade against the work
Bandsaw – linear continuous motion of saw blade, which is in form of an endless flexible loop with teeth on one edge
) and BROACHINGMoves a multiple cutting toothed tool linearly relative to the work piece in the direction of tool axis
Good surface finish & close tolerances
Cutting tool is called a broach (expensive tool due to its complicated geometry)