In the directive of commonly used treatment that introduces in front, each G instruction is general a movement of corresponding machine tool, it needs to come true with a block. To improve process designing work efficiency further, FANUC-Oi system design has fixed loop function, it stipulates to a few models aperture machines medium fixed, successive movement, with a G the instruction is conveyed, choose aperture to machine means namely with fixed loop instruction. Commonly used fixed loop dictates the work that can complete has: Bore, attack whorl and bore hole etc. These loops include normally following movement of 6 main operations: 1, locate in XY plane 2, sudden shift arrives R is planar 3, the cutting of aperture is machined 4, hole bottom movement 5, return R plane 6, return initial drop. The graph secures the solid line in the graph on main action of the loop to express cutting feed, dotted line shows rapid movement. R plane is when orifice, rapid movement changes the position with what feed moves. Commonly used fixed loop has high speed deep aperture to get boring of loop, whorl cutting loop, essence to wait circularly. In type of of; of ～ of K of ～ of F of ～ of P of ～ of Q of ～ of R of ～ of Z of ～ of Y of ～ of G89 X of ～ of G90/G91 G98/G99 G73 of process designing format: G90 /G91 -- absolutely coordinate process designing or increment coordinate process designing; G98 -- return knife dot; G99- returns R plane. G73 ～ G89 -- aperture machines means, like bore treatment, high speed deep Kong Zuan is machined, bore hole treatment; X, Y -- the positional coordinate of aperture; Z -- hole bottom coordinate; R -- safe face (R face) coordinate. When increment means, it is initial drop to be apart from to the increment of R face; When very kind, for the absolutely coordinate of R face; Q -- every time cutting deepness; P -- the suspensive time of hole bottom; F -- cutting feed speed; K -- the regulation repeats treatment time. Fixed loop is cancelled by G80 or code of 01 groups of G. CNC MillingCNC Machining