Method of Dimensional Points in Application to Flat and Spatial Curves,

The author reviews a method for designing turbine blades which permits programming and machine calculation of both blade and tool profiles and the direct use of computed data for automatic machining of models and templates. The design and production techniques comprise published research results at the Aviation Institute Instytut Lotnictwa. The basic design method is the superimposition of symmetric profile coordinates on a skeleton line representing an arc segment. Profiles C4 and NACA 65-010 for compressor blades were calculated and computation of any other profile is possible. The program was extended to computing the tangential circles for the profile whose radii correspond to that of tools used in producing the profile. A special advantage of the technique is eliminating conventional sample-making in finishing curved lines and surfaces, using for this purpose the more exact automatic tools. Scale up of drawings is not required and the accuracy of flat and spatial dimensions is of the same quality. After producing a half-finished sample with polished base and faces, the sample is reduced to dimensional points by an automatic drill and later surface finished and partially chrome plated. Additional development will permit continuous fabrication by programmed tools.