Machine Tool Base
Machine tools and other high-precision machines rely upon high stiffness, long-term stability, and excellent damping characteristics of the base material for their static and dynamic performance. The most widely used materials for these structures are cast iron, welded steel fabrications, and natural granite. Due to the lack of long-term stability and very poor damping properties, steel fabricated structures are seldom used where high precision is required. Good-quality cast iron that is stress-relieved and annealed will give the structure dimensional stability, and can be cast into complex shapes, but needs an expensive machining process to form precision surfaces after casting.
Good-quality natural granite is becoming more and more difficult to find, but has a higher damping capacity than cast iron. Again, as with cast iron, the machining of natural granite is labour intensive and expensive.
Read more about this topic: Epoxy Granite
Famous quotes containing the words machine, tool and/or base:
“The white man regards the universe as a gigantic machine hurtling through time and space to its final destruction: individuals in it are but tiny organisms with private lives that lead to private deaths: personal power, success and fame are the absolute measures of values, the things to live for. This outlook on life divides the universe into a host of individual little entities which cannot help being in constant conflict thereby hastening the approach of the hour of their final destruction.”
—Policy statement, 1944, of the Youth League of the African National Congress. pt. 2, ch. 4, Fatima Meer, Higher than Hope (1988)
“One of the great reasons for the popularity of strikes is that they give the suppressed self a sense of power. For once the human tool knows itself a man, able to stand up and speak a word or strike a blow.”
—Charles Horton Cooley (1864–1929)
“Adolescence is a time when children are supposed to move away from parents who are holding firm and protective behind them. When the parents disconnect, the children have no base to move away from or return to. They aren’t ready to face the world alone. With divorce, adolescents feel abandoned, and they are outraged at that abandonment. They are angry at both parents for letting them down. Often they feel that their parents broke the rules and so now they can too.”
—Mary Pipher (20th century)