# Numerical control lathe machines spherical error analysis to reach eliminate a method

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- source:MACKINNON CNC Machining

005mm less than, namely D=0.

01mm. To assure this precision, must control Y. By type (1) knows Y= ± ½(2Dd-d2)½(2) to pursue sketch map of 2 pairs of knives sets D=80mm, when machining ball bearing, computational earning | Y | ≤ 0.

63mm. If pursue,to knife method 2 are shown. The numerical value on dial gauge is Y value namely. The influence of error of the centre of a circle of interpolation of cutting tool circular arc and eliminate a method (with the car inside spherical for exemple) show 3 times like the graph, x is the distance of axis of Y of deviate of the centre of a circle of interpolation of cutting tool circular arc, d needs ball diameter for place, d1 is XOY plane to go up to machine a diameter actually: D/2 is radius of interpolation of cutting tool circular arc. Visible, on XOY plane, error D=D1-D=2X: On XOZ plane, the elliptical ball that shows long axis diameter to be D for diameter of D1, short axis, its error D=D1-D=2X compares a law to remove the effect of error of the centre of a circle of interpolation of cutting tool circular arc with pointwise. Graph the centre of a circle of interpolation of circular arc of 3 cutting tool affects sketch map (inside spherical) (A)2X>0, to compensation X(b)X<0, negative to compensation X graph 4 cutting tool compensate sketch map thick car to set D to need for place inside ball diameter, 1 ～ stays when thick car 1.

Half essence of 5mm car surplus, namely A1=D-(1 ～ 1.

5) . internal diameter of thick car ball A1 of diameter of interpolation of the circular arc in real measure and program is compared, get error of center of main shaft of deviate of the centre of a circle of interpolation of cutting tool circular arc to be 2X. Be like 2X>0, criterion direction of edge X axis to compensation X, be like 2X<0, lose along X axis direction to 4) of compensation X(graph. Half thick car stays 0.

Surplus of 5mm fine vehicle, namely A2=D-0.

5, measure next, quite, method of cutting tool compensatory is Alexandrine, give place to need till the car inside spherical. Spherical principle is same inside car spherical outside surface and car, compensation way is same, what what differ is cutting tool installation way is opposite. Because pace of numerical control lathe receives electromotor pulse equivalent,can amount to 0.

01, 0.

005, 0.

001mm, precision of curve of circular arc interpolation is in accordingly ± 0.

01, ± 0.

005, ± 0.

001mm, the basis is machined spare parts demand, choose corresponding numerical control lathe, can satisfy production to need actually. CNC Milling