Wasting Processes Flashcards
Milling
Milking involves using a high powered rotary cutters to remove material by advancing the cutter into a workpiece
The work is clamped I it the centre of the table
Table can run in the X, Y and Z directions to cut slots, shapes, shaped edges and thread holes
Can be CNC - CNC router
Turning
This is carried out on a centre lathe
The workpiece is held in a rotating chuck and machines to reduce diameter, square or ‘face off’ the end, thread and drill
Can be done manually or using CNC lathes
The material is machined by citing tools held in a tool post, which can be moved in and out and along the bar
Flame cutting
This method uses oxy-acetylene gas and a special torch to deliver a very intense and focuses flame above 3500 degrees C
Used to cut low carbon and alloy steel plate
Has an additional jet of oxygen to intensify the flame and pierce the metal
Doesn’t require electricity
Difficult to maintain a parallel line with high levels of tolerance
Plasma cutting
Plasma is an electrically conductive, super-heated ionised gas
A plasma cutter uses this conductive gas to transfer the energy from the power supply to a conductive material such as steel plate
Heat generated by the plasma can be 28000 degrees C which quickly burns through the material and blows it away
Resulting cut is fast and clean
Laser cutting
Can be used in industry for precision cutting metals
But lower powered lasers are available in school workshops to cut acrylic and manufactured boards
Uses a high powered laser beam that is directed through optics
Laser head contains a lens that focuses the laser into a fine beam for cutting and engraving
Laser beams have a very fine tolerance (<1mm)
More accurate and uses less energy than plasma cutting but can’t cut the same thickness of material
Can cut a broader range of materials than plasma cutting
Punching/stamping
Uses computer-controlled machines that stamp out sections of sheet material
Uses the shearing action of metal placed between an upper tool (punch) and a lower tool (die)
Suitable for small to medium size production runs of metals from 0.5mm to 6mm thickness
Advantages of laser cutter over milling/routering
Can cut faster
High level of accuracy and repeated accuracy
Less material wasted and less swarf to deal with
Finer tolerance - more intricate shapes can be cut
Tooling doesn’t need changing
Materials don’t need clamping
Can cut a wider range of materials
