Physics Servo Drive Mounts 1. Why did Astro-Physics choose a servo motor drive system rather than stepper motors?
Stepper motors have limited slewing ability and lose torque at high slew rates. They can stall without warning while slewing. Even when driven in the micro-step mode, they are not as accurate as a zero-cogging servo drive. Steppers take more power to run and will drain batteries much more quickly. Back to top 2. What is the pointing accuracy? The inherent pointing accuracy of Astro-Physics mounts and the positioning software is very high. At two star parties in 1997, we used the following system: computerized 1200GTO mount, Astro-Physics 180 f7 StarFire EDF and IMG260 CCD camera (512 x 512 pixels) from Finger Lakes Instrumentation. Once polar alignment was achieved, we selected images from one side of the sky to the other. Each time the image appeared on the screen, it was located on the same part of the chip as the previous images. We were very impressed with the consistency of the system. The IMG260 chip is very fast, achieving excellent results in just 5 minutes for most objects. Th
