1, workpiece size is exact, the surface is bright and clean spend difference Breakdown reason: Cutting tool point of a knife is damaged, not sharp; The machine tool produces resonance, place not smooth; The machine tool has creeping appearance; Treatment technology is bad. Solution: Cutting tool wears away or damage hind is not sharp, grind a knife afresh or the cutting tool with better choice is new not smooth to knife; machine tool produces resonance or be being placed, adjust a level, lay next foundations, what machinery of fixed and smooth; produces crawl is former because procrastinate board slideway wears away fierce, guide screw ball wears away or become loose, the machine tool should notice to maintain, iron wire should be swept after commuting, add lubricating oil in time, suit the cooling fluid that workpiece machines in order to reduce attrition; choice, below the condition that can obtain other working procedure to machine a requirement, choose higher main shaft rotate speed as far as possible. 2, phenomenon of differ in roll end diameter of workpiece generation taper Breakdown reason: The standard that the machine tool sets was not adjusted good, one tall one low, when generation places turning of not smooth; to grow an axis, contributive data is harder, cutting tool penetration of a cutting tool is deeper, cause thimble of tailstock of; of phenomenon letting a knife and main shaft different heart. Solution: Use gradienter adjusts the level of the machine tool to spend, lay next solid groundwork, had secured the machine tool raise its tenacity; to choose sound technology and proper cutting feed to avoid cutting tool to suffer force to let knife; adjust tailstock. 3, driver is phasic the lamp is normal, and the work measure size that treatment comes out Breakdown reason: The machine tool procrastinates board long-term high speed moves, bring about filar lever and bearing to wear away the repetition of; tool carrier locates precision produces deviation; to procrastinate in be used for a long time board every time can accurate return treatment start, but treatment work measure still changes. This kind of phenomenon is caused by main shaft commonly, the high speed roll of main shaft makes bearing wears away serious, bring about treatment dimension to change. The metal machines small letter, content is pretty good, be worth to pay close attention to. Solution: Lean in tool carrier bottom with dial gauge, edit program of a fixed loop through the system at the same time, the examination procrastinates board repeat fixed position precision, adjust filar lever clearance, change bearing; repeats fixed position precision with what dial gauge checks tool carrier, adjust machinery or change tool carrier; detects with dial gauge after processing work accurate return program start, it is OK to be like, overhaul main shaft, change bearing. Wanted to affirm rate of occurrence breakdown of lathe of numerical control of cutting of which part high speed, attaint only, we can undertake next plan solve a problem. Through these measure basically can find out the place of the problem.