A PDC cutter is used as a cutting tool in a VTL where the working piece or piece being cut is a cylinder of granite. The PDC cutter moves radially inward removing a fixed amount of rock on each pass from the top surface of the spinning rock. The rpm of the rock is increased as the PDC cutter moves towards the center to keep the cutting action at a constant surface speed. As the cutter wears in the process of cutting the rock a load cell mounted on the vertical axis of the machine measures all the components of the cutting reaction force. When the normal reaction force crosses a high limit threshold the PDC cutter’s VTL score can be defined. A high RPM rock speed test is used to measure a PDC cutter’s thermal stability and a low RPM rock speed test is used to define a PDC cutter’s wear abrasion resistance.
Features / Benefits
Even though VTL PDC cutter testing is a widespread tool in the drill bit industry, Varel is perfecting this technology to better define PDC cutter characteristics. Through this technology the Varel engineers are defining PDC cutter choices for customer specific applications leading to better bit performance and reduced overall costs for our customers.