How good is the linear motor?
The linear motor is another case of a technology with mixed reviews. They are being used in greater numbers by some machine tool manufacturers. But there are still a lot of questions about their performance, reliability, and cost. In an effort to clarify the situation, NIST has developed a test bed that is looking at key performance characteristics such as accuracy, acceleration, stiffness, and heat generation. “This project was motivated by the difficulties encountered by the machine tool industry in implementing linear motors,” says Alkan Donmez, group leader for Machine Tool Metrology in the Manufacturing Metrology Division. “The project will also study the controller aspects of linear motors, failure modes, methods for predicting impending failure and remaining life, as well as estimating the mean time between failure.” First part, good part. The classical feedback quality assurance technique is to make a part, check it, then modify the process and try again until the resulting par
