Some shops would measure a productivity improvement in terms of the extra capacity freed up on a given machine tool. Texas Arai (Houston, Texas) measures its productivity gains in terms of the number of machines it no longer needs. This maker of machined oilfield couplings is now able to use 70 lathes to meet a workload that once demanded 90 lathes. A number of technology improvements all contributed to this more effective use of capital equipment, but one overriding factor is the company's close relationship with its lathe supplier, Mori Seiki (Irving, Texas). The machine tool builder has continually worked with Texas Arai over the years to tailor the turning machines to this manufacturer's particular application. The result has been a series of efficiency gains.
For example, on belt-driven headstocks used on smaller lathes, the builder modified machines that were already performing well for the company to use vee belts in place of typical flat belts. The resulting extra torque let Texas Arai achieve faster metal removal rates on some of its turned parts. Similarly, the builder was also able to modify some of its machines for this company's application to extend the size of the X- and Z-axis feed systems.
In addition, working with distributor JRP Machinery (also in Houston), the machine tool builder helped the company implement high pressure coolant for its turning processes. Significant savings in perishable tooling costs came as a result.
Texas Arai produces couplings in 20 different sizes, with diameters ranging from 2 3/4 to 14 5/8 inches. Within this range of sizes are the possibilities for 15 material grades and 15 different thread patterns. Given the type and range of parts, effective turning is fundamental to this company's business.
A commitment to tailor the equipment to Texas Arai's particular needs is one reason the company has remained with its lathe supplier. Another reason is more fundamental, according to Frank Carlin, company vice president and general manager. The company has watched the reliability of these machines over the years. The plant runs them 20 hours per day. "When you run a machine that much, durability becomes a big issue," he says.