Development of CMM auxiliary equipment for tiny hole measuring

According to the limited measurement range of specific coordinate measuring machine (CMM), a reverse test method was put forward, and an auxiliary measuring equipment for tiny hole was developed. A measuring method for tiny hole was formulated, which using gauge head trigger signal of CMM as the test signal. The principle which was the tiny hole moving but not moving gauge head was used and the corresponding measurement software was designed so that the small measurement range was expanded. The measurement precision influence factors were analyzed and the measurement scheme was optimized. The results indicate that: then the measurement range of tiny hole is expanded to 1.0mm based on the combination of auxiliary equipment and CMM. The precision error is 0.004 mm which meets the measurement requirements.