Research to the effect of machining parameter on form error in the milling of free form surface

Production of freeform surfaces is very important for transportation, electronics and aerospace industries. To increase the processing efficiency and to approach the ideal form for manufacturing of this surface is achieved through the optimization of processing parameters. In this study, we investigate the effects of different tool path on form error which appearance the manufacturing of freeform surface formed by the B-spline curves. B-spline curves were obtained using a program developed in MATLAB and generated surface of the tensor multiplication of the curve. With free-form surface has become solid at CAD (Computer Aided Design) and tool paths was created by using CAM(Computer Aided Manufacturing) program. Sample was machined three levels as rough cut, semi rough cut and finish cut. Rough cut (HM rough) which was same for all sample, three different semi rough method (semi rough, counter rough, parallel rough) and four finish cutting method (curve parallel, parallel scanning, parallel linear, parallel fixed z) was apllied and 12 samples was machined. The machining samples were scanned with a 3D surface scanning method have been mapped. Surface was divided by 9 different regions and 10-14 between point which was relatived to wide of surface was measured for cordinate point (X,Y,Z) on every region, later the measured was compared with measurements on the reference surface. The best semi rough tool path was determined by Counter Rough and finish tool path was determined by Curve Parallel. The worst semi rough tool path was determined by Parallel Rough and finish tool path was determined by Parallel Scanning. Improvements of up to 17 was obtained by feed was reduced %10 in the regions where intensive forms of error in the best results of tool path. KEY WORDS: Free form surface, B-Spline curve, form error, tool path.