Finally, the measures to reduce the radial circle run-out error of the crankshaft main journal have be presented.

Horizontal double sided NC combined drilling machine is specially designed for the machining of main shaft journal hole and crank arm journal straight oil hole of crankshaft with six cylinders.

The crankshafts shown in Fig 1-4 is actually made up of various parts such as main bearing journals, rod journal, crank arm, bearing, counter balanced weight and flywheel end.