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Machining of Curved Geometries. Pelton cup. Impeller. Knee joint prothesis. Intake manifold. Forging die for Blade. Pinion. PARAMETRIC SURFACES. Surfaces of Known Form Plane surface Cylindrical surface Conical surface Spherical Surface Toroidal Surface . PARAMETRIC CURVES.
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Machining of Curved Geometries • Pelton cup • Impeller • Knee joint prothesis • Intake manifold • Forging die for Blade • Pinion
PARAMETRIC SURFACES Surfaces of Known Form Plane surface Cylindrical surface Conical surface Spherical Surface Toroidal Surface
PARAMETRIC CURVES Parametric Representation of Curve x = f ( u ); y = g( u ); z = 0; 0 u 1.0 u = 1 u = 0
PARAMETRIC CURVES Parametric Representation of Curve x = f ( u ); y = g( u ); z = 0; 0 u 1.0 u = 1 u = 0
OFFEST CURVE dx dy du du Parametric Representation of Curve x = f ( u ); y = g( u ); z = 0; 0 u 1.0 pn= - pu= dy dx du du 0 0
OFFEST CURVE nx pn ny n= = Parametric Representation of Curve x = f ( u ); y = g( u ); z = 0; 0 u 1.0 pn 0 Parametric Representation of Offset Curve X = f ( u ) + nx r Y = g( u ) + ny r Z = 0
CNC Programming Gouging
CNC Programming 1 kmax= rmin
TOOL SELECTION dx (pu x puu ) . (pux puu) du k2= pu= dy (pu. pu)3 Parametric Representation of Curve x = f ( u ); y = g( u ); z = 0; 0 u 1.0 du d2x 0 du2 puu= d2y du2 0
PARAMETRIC SURFACES Surfaces of Known Form Plane surface Cylindrical surface Conical surface Spherical Surface Toroidal Surface
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PARAMETRIC SURFACES Flat End Mill Ball End Mill
FREE-FORM SURFACES Parametric Surface x = f (u, w); y = g (u, w); z = (u, w); 0 u 1.0; 0 w 1.0 Offset Surface X = f (u, w) + nx.r; Y = g(u, w) + ny.r; Z = (u, w) + nz.r; 0 u 1.0; 0 w 1.0 δx δx δu δw δy δy (pu x pw ) pu = pw = δu δw n= (pu x pw) δz δz δu δw
FREE-FORM SURFACES Parametric Surface x = f (u, w); y = g (u, w); z = (u, w); 0 u 1.0; 0 w 1.0 E = (pu . pu ) F = (pu . pw ) G = (pw . pw ) L = (puu . n ) M = (puw . n ) N = (pww . n ) (LN – M2 ) = k1 k2 K = (EG – F2 ) (EN + GL -2FM) = 0.5(k1 + k2) H = 2 (EG – F2 ) (pu x pw ) n= (pu x pw)
p(u, 1) RULED SURFACE p(u, 0) Input Two curves p(u, 0), p(u, 1) p(u, w) = (1-w) p(u, 0) + w p(u, 1)
p(0, 1) BILINEAR SURFACE p(1, 0) p(1, 1) p(0, 0)
BILINEAR SURFACE(HYPERBOLIC PARABOLOID) Four Corner Points p(0, 0), p(1, 0), p(0, 1), p(1, 1) p(u, w) = (1-u) (1-w) p(0, 0) + u (1-w) p(1, 0) + (1-u) w p(0, 1) + u w p(1, 1)