Cutting performance of various CNC drilling cycles at diverse cutting speeds concerning hole dimension error, surface roughness, and cutting time

Many drilling cycles with various characteristics are available in CNC machining. This study empirically verified the distinctive drilling cycles with different cutting speeds to evaluate their cutting performance. The simple/spot drilling (G81 and G82) and peck drilling (G73 and G83) were operated at various cutting speeds on the ST-37 workpiece using the HSS drill bit. The drilled-hole dimension error, surface roughness, and drilling time were measured. The results confirmed that the peck drilling achieved lower dimension error and produced smoother surfaces than the simple/spot drilling. They revealed that G73 exhibited the slightest diameter error, and G83 achieved the finest surface roughness. Further, the results demonstrated that the diameter error decreased with increasing cutting speed. Still, the high cutting speed caused rapid wear on the cutting edge of the drill bit, resulting in a rougher drilled surface. In addition, various cutting speeds did not affect the drilling time required. However, it significantly impacted the diameter error and the surface roughness.