Abstract :
Measurement of the measuring stop position is by an electromagnetic digitizer and the control system is built-up from standard plug-in transistor logic units. The drive of the measuring stop is by a two speed pole amplitude modulated type pole-changing induction motor. Use is made of a fast traverse, slow approach cycle, and the final approach is always from one direction to eliminate back-lash errors. A pneumatic brake is used to bring the stop to rest at the final position. A repeatable accuracy of better than 1/16 in has been obtained on a stop capable of measuring length of up to 60 ft.
