3.1e machining

product design a level

machining

various processes in which a piece of raw material is cut into desired final shape and size by a controlled material-removed process
processes that are controlled material removal are known as subtractive manufacturing
part of the manufacture of metal products
cnc is used for most machining now where computers are used to control operation of mills, lathes etc.

milling

shaves off waste from block’s surface to form desired shape, many are only horizontal and vertical, can be controlled by cnc
metal is removed at a faster rate, accurate, various attachments, one-off or low-run batch production
expensive, highly skilled workforce, high cutting temps generated

plain milling machine vice

used for holding work which has parallel sides
vice is bolted to table using t-slots in machine table

swivel base vice

graduated in degrees and allows vice to swivel in horizontal plane, swivel base gives it a greater degree of versatility, but should be avoided when doing heavy rough cutting operations

universal vice

allows operator to tilt work piece 90 degrees in vertical plane as well as swivel 360 degrees in horizontal plane

slab mill cutter

for heavy cutting of large and flat surfaces

side and face mill cutter

has cutting edges on periphery and sides of teeth for cutting shoulders and slots

slitting saw mill cutter

for cutting deep slots or for parting off

end mill cutter

commonly used for facing, slotting and profile milling

slot drills

for producing pockets without drilling a hole before hand

face milling cutter

for heavy cutting and facing

routing

similar to milling, associated with woods, plastics and composites
when routing wood the work is clamped to bench and a fence is used to keep the cutter parallel to edge
faster than milling

drilling

process of making holes by using a rotating cutting tool that is secured in a hand-operated drill or drilling machine
when drilling wood, due to friction it can overheat and burn
less effort required, reduced time, drill speed can be changed, wide range of bits
chuck requires frequent changing, accuracy is down to skill of operator, difficult to drill holes in centre of cylinders

plain milling machine vice

used for holding work which has parallel sides
vice is bolted directly to table using t-slots in machine table

tilting drill vice

allows the operator to tilt the work piece 90 degrees in vertical plane

drill clamp

useful clamp for pillar drill, especially when drilling awkward metal components

hand vice

spring loaded vice, tightened by a large wing nut best suited for small items

drill shanks

parallel shank, taper shank

drill bits

twist drill, countersink bit, flat bit, hole saw, forstner bit, auger bit, tank cutter

centre lathe

turn cylindrical metal bars to reduce their thickness or to shape them, work is held in a chuck that is rotated while the tool is held firmly in tool post
as the work rotates against the cutting tool, the wedge action cuts away the material, the tools are made from high-speed steel
rotation speeds are set depending on material used, thickness of bar and speed of rotation, lubricant eases cutting process, cools the metal and flushes away the swarf
high tolerance, threads can be cut, wide range of tools
expensive, highly skilled workers, high temp generated

tail stock

commonly used for objective of primarily giving an outer bearing and support the circular job being turned on centres

tool post

important part of carriage, which fits in a t-slot in the compound rest and holds the tool holder in place by the tool post screw

centre lathe processes

facing, parallel turning, taper turning, parting, drilling, knurling

drilling and boring

starting by drilling with centre lathe, used t drill slightly into material and creates starting point for other drills that are going to be used
once a hole has been produced, machine twist drills enlarge and if necessary to drill all way through
important to use a coolant, should be fed onto drill bit to keep cool, will help prevent jamming and overheating

wood lathe

holds a piece of wood and spins it, operator holds a chisel on a rest and guides it over the spinning wood to chisel wood away

wood lathe tools

scrape, skew chisel, gouge, bowl scraper, parting tool, spear point chisel

stamping

where a piece is cut out of a sheet of material, usually to make a blank for further processing
usually done on cold metal sheet

pressing

once stamped out there are also a range of secondary processes that can be added to manufacture complex 3d parts

bending

material is deformed or bent along a straight line

flanging

material is bent along a curved line

embossing

material is stretched into a shallow depression
used for adding decorative patterns

reducing

used to gradually reduce diameter of open end of a vessel or tube

curling

deforming material into a tubular profile
door hinges are common example

hemming

folding an edge over onto itself to add thickness

stamping and pressing

precise method, speed of stamping out process is faster, stamping out can cut through more layers at once, automated, can be done rapidly and repetitively without distorting metal
expensive especially for short runs, longer lead times are necessary , costs if design changes