- published: 02 Jul 2015
- views: 1600484
Turning is the process whereby a single point cutting tool is parallel to the surface. It can be done manually, in a traditional form of lathe, which frequently requires continuous supervision by the operator, or by using a computer controlled and automated lathe which does not. This type of machine tool is referred to as having computer numerical control, better known as CNC. and is commonly used with many other types of machine tool besides the lathe.
When turning, a piece of material (wood, metal, plastic, or stone) is rotated and a cutting tool is traversed along 2 axes of motion to produce precise diameters and depths. Turning can be either on the outside of the cylinder or on the inside (also known as boring) to produce tubular components to various geometries. Although now quite rare, early lathes could even be used to produce complex geometric figures, even the platonic solids; although until the advent of CNC it had become unusual to use one for this purpose for the last three quarters of the twentieth century. It is said that the lathe is the only machine tool that can reproduce itself.
[The women of Paris mourn their lost loved ones.]
Women
Did you see them
Going off to fight?
Children of the barricade
Who didn't last the night?
Did you see them
Lying where they died?
Someone used to cradle them
And kiss them when they cried.
Did you see them
Lying side by side?
Who will wake them?
No one ever will.
No one ever told them
That a summer day can kill.
They were schoolboys
Never held a gun
Fighting for a new world
That would rise up like the sun
Where's that new world
Now the fighting's done?
Nothing changes, nothing ever will
Every year another brat, another mouth to fill.
Same old story, what's the use of tears?
What's the use of praying if there's nobody who hears?
Turning, turning, turning, turning, turning
Through the years.
Turning, turning, turning through the years
Minutes into hours and the hours into years.
Nothing changes, nothing ever can
Round and round the roundabout and back where you began!