Brandon Fisher, Center Rock founder and CEO (left), with Richard Soppe, down-hole-drill project manager, and their worn 26-in. Low Profile drill that made the final bore to rescue 33 Chilean miners trapped 2,067 ft underground.
Center Rock uses GibbsCAM to program all its CNC machine tools, including Doosan MX2500 multi-task machines used to machine complex parts and all Low Profile drill bits. Here, GibbsCAM Cut Part Rendering displays multiple views of toolpath for machining the 7-7/8-in. LP drill bits loaded on the 26-in. and 28-in. LP drills.
From August through October, 33 Chilean miners earned the admiration of the world for their fortitude as they maintained composure and willed themselves to survive the mine’s collapse. Less widely celebrated have been the engineers who devised the miners’ rescue, and the equipment designers and manufacturers who made it possible. Among the latter is Center Rock Inc., which manufactures and distributes air-drilling equipment, including the Low Profile (LP) Hole Opener drills used in the rescue effort.
Among those noticing Center Rock’s contribution is Gibbs and Associates, the developer of GibbsCAM® software for programming CNC machine tools, which congratulated its customer for helping to shorten the rescued time by more than two months from the earliest estimates. Center Rock’s drills produced on machine tools programmed with GibbsCAM.
Center Rock has been using GibbsCAM at its Berlin, Penn., manufacturing center for almost six years. It has reduced it manufacturing costs significantly using multi-task machines programmed by GibbsCAM, eliminating the cost of fixtures and the time and cost of handling and multiple set-ups. More reasons for using GibbsCAM include its ease of use and its ability to program all configurations of CNC machining centers, turning centers, mill-turn and multi-task machine (MTM) tools.
The drill makers has been using the GibbsCAM mill-turn and 3-axis milling modules since 2005, and GibbsCAM rotary milling and advanced MTM modules since 2006. The integrated GibbsCAM modules open SolidWorks CAD models directly, so that Center Rock programmers can use and manipulate engineers’ solid-model geometry to program their seven CNCs.
For its turning operations, Center Rock uses three Doosan 2-axis lathes: a Puma 300, a Puma 400 and a Puma 480. Three-axis milling and rotary milling is done on two Mazak horizontal machining centers, while parts with complex geometry and parts that would otherwise require multiple set-ups on lathes and machining centers are made with two Doosan Puma MX2500 multi-task machine tools.
Center Rock’s drills use highly compressed air instead of fluids to drive drill bits and clear rock fragments. Other drills grind through rock, typically with roller cone bits, flushing and clearing the ground rock away from drill bits with water or other fluids. A Center Rock drill, representing newer technology, uses multiple pneumatic hammers, each steadily pounding a drill bit to crush rock as the drill rotates, much like a group of rotating jack hammers. In addition to driving the hammers, the compressed air is circulated to blow rock flakes and dust upward away from the bits. These newer DTH (down the hole) drills cut through hard rock much faster than older, fluid-operated systems.
In the Chilean mine rescue, Center Rock used three drill sizes to penetrate through 2,067 feet of the earth’s surface. The first was a 5.5 ×12 QL 120 hole opener, used to widen one of the ventilation holes from 5.5 inches diameter to 12 inches diameter, which larger drills could use as a guide or pilot hole. The second and third choices were LP (low profile) drills of 28-in. diameter and 26-in. diameter, respectively, both configured as hole openers, and each using four pneumatic hammers and four, 7-7/8-inch diameter, tungsten steel drill bits.
Among the components that Center Rock machined for the LP drills are the flange and receivers at the top, the flat plates, the chucks for the hammers, and a long, serrated pilot or “nose.” However, the hardest parts and those with the most complex geometry are the LP drill bits, which Center Rock manufactures with various face shapes for specific applications. In addition to turning operations, areas of each bit may require flat, contour, radial or axial milling, and each bit may require various holes at different angles. Combined, the features lend themselves well to multi-task machining. With GibbsCAM MTM software and the Doosan MX2500, Center Rock programmers and machinists make each bit in a single set-up, eliminating the cost of fixtures and the time and cost of handling and multiple set-ups.
Because GibbsCAM integrates all operations, the CNC programmer stays within the same user interface, without having to exit an active module to initiate another, when programming mill-turn or MTM. All operations – turning, milling, drilling, and non-cutting motion, such as tool changes, turret motion and transfers between spindles – are executed within the same interface.
GibbsCAM MTM provides automated and interactive ways to insert syncs (wait codes) and displays flows for each tool group side by side, making it easy for the programmer to optimize the toolpath. It also includes toolpath verification with dynamic display of tool motion and material removal, so the programmer can verify the toolpath whenever he wants: after each operation as it is completed, after a group of operations, or when the entire toolpath is completed.
Much as Center Rock used its own technology and expertise to cut in half the time to rescue the 33 miners – from five months to two and a half – Center Rock programmers and machinists speed up production of drills and drill bits every day, using GibbsCAM to drive their Mazak machining centers, Doosan Puma lathes and MX2500 MTM machines.