Drill bit manufacturers have substantially improved polycrystalline diamond (PCD) cutters and drag bit designs since their introduction in 1972. PCD drill bits are now approaching the rolling cone ...

At first glance, there probably doesn't seem to be much to drills. Simply install a bit, mark where you plan to drill, and drill away. However, the fact is there's a lot to consider when drilling, ...

The calculation method proposed in this series, using actual gear ratio for the cones, allows the designer to determine and optimize kinematic parameters of drill bits. The analysis is applicable to ...